resistance switching materials and devices

Resistance Switching Materials and Devices

Patent Landscape by Blaise Mouttet

3/21/2014 1

Quick Links to Companies

• 4D-S Ltd. • Adesto Technologies • Axon Technologies • Contour Semiconductor • Crossbar, Inc. • Elpida Memory, Inc. • Hewlett-Packard Co. • IBM • Intel Corporation • Intermolecular, Inc. • Macronix International • Micron Technology, Inc. • Ovonyx, Inc.

3/21/2014 2

• Panasonic • Qimonda Ag • Samsung Electronics Co., Ltd. • Sandisk • Seagate Technology • Sharp • SK Hynix • Sony Corporation • Spansion LLC • Symetrix Corp. • Toshiba • Unity Semiconductor

Quick Links to Graphs/Tables

• Patented Resistance Switching Materials • Patented Resistance Switching Applications • Top Assignees • Other Notable Companies/Start-Ups • Top Academic Patent Assignees • Top Assignees vs. Patent Expiration Years • Materials vs. Patent Expiration Years • Assignees vs. Claimed Resistance Switching Material • Assignees vs. Claimed Metal Oxide ReRAM Material • Assignees vs. Claimed Silicon-Based ReRAM Material • Assignees vs. Claimed Carbon-Based ReRAM Material • Assignees vs. Claimed Application

3/21/2014 3

Scope of Patent Landscape

• Results include issued US Patents spanning from the 1960s until February 25, 2014. Foreign patents and pre-grant published applications were not included.

• Primary focus of patents collected is PCRAM (phase change), ReRAM (metal oxide), CBRAM (ionic/electrolytic), and other non-volatile memory materials based on a resistance switching effect.

• Patents claiming MRAM or a magnetic material for resistance switching were excluded except in cases where an independent claim was broad enough to encompass PCRAM, ReRAM, or CBRAM.

• Optically (e.g. laser) driven resistance switching materials were excluded except in cases where an independent claim was broad enough to encompass electrically driven resistance switching.

3/21/2014 4

3/21/2014 5

25 31 38 62 65 113 122 224 242 194 162 25

1 4 6 12 10 11 14 45 60 53 101 7

4 17 24 26 23 31 14 35 24 35 33 4

8 13 18 8 5 3 2 2 6

2 2 4 10 9 15 1

1 5 2 8 3 5 2 3

1 1 3 1 6 1 4 2

1 1 3 3 7 1

3 2 1

3 2 1

2002 2004 2006 2008 2010 2012 2014

Patented Resistance Switching Materials (Granted US Patents, Jan. 2003-Feb. 2014)

phase change

metal oxide

ionic/electrolytic (e.g. metal doped chalcogenide,CBRAM)

molecular or polymer

elemental carbon (e.g. graphene, nanotube)

nanoparticles

organic

silicon-based

metal nitride

other

Notes: 1)Some overlap exists between categories such as ionic/electrolytic and metal oxides when oxygen vacancies act as ions. 2)The categorization was determined based on how the material was claimed in the patent. 3)The ionic/electrolytic category primarily includes the metal doped chalcogenides used in CBRAM.

3/21/2014 6

1 1 2 4 3 9 6 5 12 1

2 1 5 1 6 4 4 5 9 1 5

1 1 4 4 5 9

2 3 5 1 5 4

1 3 2 3 1 1 1 3

1 1 4 2 1

1 2 2 1

1 4 2 1

1 1

2002 2004 2006 2008 2010 2012 2014

Patented Resistance Switching Applications (Granted US Patents, Jan. 2003-Feb. 2014)

3D stacking

logic/computation

3-terminal device

neuromorphic

encoder/decoder/mux

electromagnetic/radio wave (e.g. RFID)

microcontroller/signal processing

test circuit

error correction

Notes: the categorization is based on a claimed application other than just memory or manufacturing memory

3/21/2014 7

5 9 9 22 24 53 69 99 110 108 70 9

18 30 39 49 40 40 29 45 44 62 78 16

1 3 8 5 29 61 73 100

1 4 8 10 9 21 31 32 51 44 21 2

1 8 2 13 25 24 41 31 36 7

1 8 2 13 25 24 41 31 36 7

1 4 3 3 4 21 34 36 56 3

3 7 6 27 22 35 42 7

3 9 29 24 37 29 11 3

10 5 20 6 14 10 1 3 12 18 35 1

1 2 4 10 15 33 55 1

1 5 13 18 14 10 8 8 9 5 15 2

15 42 30 18 1

7 7 1 4 10 5 7 7 13 6 11 2

4 6 5 3 7 2 8 21

3 11 16 12 7 3 1

2 4 4 6 5 4 7 8 3 1

2002 2004 2006 2008 2010 2012 2014

Top Assignees for Resistance Switching Materials (Granted US Patents, Jan. 2003-Feb. 2014)

Samsung

Micron

Toshiba

Macronix

Ovonyx

IBM

SK Hynix

Sandisk

Qimonda

Hewlett Packard

Panasonic

Sharp/Xenogenic LLC

Seagate

Intel

Sony

Elpida

Spansion

3/21/2014 8

5 12 21 5 13 5 8 17 9 8 1

1 2 7 15 29 6

4 3 6 6 1 4 3 4

7 18 5

1 2 2 4 3 3 1 2 2 3

1 1 1 3 2 3 3

2 3

1 1 1

2002 2004 2006 2008 2010 2012 2014

Other Notable Companies or Start-ups for Resistance Switching Materials (Granted US Patents, Jan. 2003-Feb. 2014)

Unity Semiconductor

Intermolecular, Inc.

Adesto Technologies

Crossbar, Inc.

Axon Technologies

Contour Semiconductor

4D-S Ltd.

Symetrix

3/21/2014 9

2 1 2 1

2 3

1 1 1 1

1 1 2

1 1 1

3

2 1

1 1

1 1

2002 2004 2006 2008 2010 2012 2014

Academic Institutions having Resistance Switching Material Patents (Granted US Patents, Jan. 2003-Feb. 2014)

Korea Institute of Science and Technology

University of California

Stanford

Boise State University

Yonsei University

Seoul National University

University of Pennsylvania

University of Houston

University of Michigan

Top Assignees vs. Patent Expiration Years

3/21/2014 10

Count of Publication Number Expiration Year

Current Assignee 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 Expired Grand Total

Samsung Electronics Co., Ltd. 6 6 2 9 41 65 55 86 85 83 74 50 19 8 589

Micron Technology, Inc. 1 9 2 4 65 68 38 31 58 27 16 45 41 45 32 9 2 493

Toshiba 1 11 2 5 1 10 30 74 63 69 18 2 286

Ovonyx, Inc. 2 3 16 2 4 17 24 16 23 16 22 19 10 21 20 10 5 17 247

Macronix International Co. Ltd. 10 10 17 13 43 53 25 28 21 13 1 234

International Business Machines 3 7 18 17 21 27 36 23 18 7 13 190

Hynix Semiconductor Inc 1 4 3 7 7 28 37 34 35 9 165

Sandisk 3d Llc 2 3 1 14 8 22 15 30 31 17 6 149

Qimonda Ag 6 23 29 26 34 17 6 2 1 1 145

Hewlett-packard Company 7 2 5 8 9 3 19 5 3 1 20 23 18 4 10 137

Panasonic Corporation 3 2 2 12 23 21 36 21 1 121

Seagate Technology 11 67 25 2 1 106

Unity Semiconductor Corporation 14 27 15 2 7 3 10 5 13 4 2 2 104

Intel Corporation 9 8 7 4 8 10 7 10 4 6 4 3 1 81

Round Rock Research, Llc 8 36 11 4 1 4 4 4 1 73

Xenogenic Development LLC 5 6 17 12 12 7 3 4 66

Intermolecular, Inc. 4 5 24 5 15 7 60

Sony Corporation 1 1 2 10 9 3 1 8 9 9 4 57

Elpida Memory, Inc. 1 1 10 10 9 7 7 7 1 53

Spansion Llc 6 3 3 8 5 9 3 7 44

Renesas Electronics Corporation 3 8 10 10 4 2 1 1 2 2 43

Sharp 1 2 1 2 2 9 3 2 5 8 6 1 42

Stmicroelectronics Inc. 1 5 3 2 4 2 2 9 8 5 1 42

Adesto Technologies 7 6 4 2 7 1 2 2 31

Crossbar, Inc. 11 16 3 30

Industrial Technology Research Institute 1 6 5 3 4 5 4 2 30

Infineon Technologies 1 1 10 9 3 3 1 1 29

Axon Technologies 19 2 1 1 1 1 1 1 27

Notes: patent expiration years were estimated assuming maintenance fees will be paid, already expired patent includes patents which prematurely expired based on a failure to pay a maintenance fee

Materials vs. Patent Expiration Years

3/21/2014 11 Notes: patent expiration years were estimated assuming maintenance fees will be paid, already expired patent includes patents which prematurely expired based on a failure to pay a maintenance fee

Count of Publication Number Expiration Year

Row Labels 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 Expired Grand Total

(blank) 8 28 29 2 10 12 55 68 104 79 139 166 180 210 366 307 274 84 34 2155

phase change 3 20 7 2 1 22 27 32 50 96 142 125 167 194 179 132 74 24 47 1344

metal oxide 1 1 2 8 9 14 20 21 46 52 50 49 42 9 3 327

ionic/electrolytic (e.g. metal doped chalcogenide, CBRAM) 22 3 1 1 34 44 17 13 36 13 9 19 29 16 15 5 3 280

molecular/polymer 8 6 18 11 3 3 5 1 2 2 2 12 73

carbon 1 2 2 3 3 14 11 6 1 1 44

nanoparticles 1 8 4 3 3 2 3 3 1 1 2 31

silicon 1 1 1 2 2 6 3 2 9 27

organic 1 1 6 4 5 1 1 19

metal nitride 3 2 1 6

metal hydride 2 2

hydrogen 2 2

porous 1 1

titanium alloy 1 1

metal alloy 1 1

ceramic 1 1

Grand Total 11 71 37 9 21 41 137 163 191 210 351 338 415 490 647 527 416 126 113 4314

Assignee vs. Claimed Resistance Switching Material

3/21/2014 12

Current Assignee (blank) phase change

metal oxide ionic/electrolytic (e.g. metal doped chalcogenide, CBRAM)

molecular/polymer

carbon nanoparticles silicon organic metal nitride

metal hydride

Samsung Electronics Co., Ltd. 257 275 34 6 11 1 1 4

Micron Technology, Inc. 234 112 9 132 1 5

Toshiba 243 15 17 4 4 1 2

Ovonyx, Inc. 80 167

Macronix International Co. Ltd. 126 94 12 2

International Business Machines 59 110 10 4 2 2

Hynix Semiconductor Inc 33 125 5 1 1

Sandisk 3d Llc 100 7 19 20 2

Qimonda Ag 98 39 1 3 1 1 1 1

Hewlett-packard Company 82 7 3 13 25 3 3 1

Panasonic Corporation 66 2 51 1 1

Seagate Technology 85 4 1 15

Unity Semiconductor Corporation 77 24 3

Intel Corporation 12 68 1

Round Rock Research, Llc 48 20 5

Xenogenic Development LLC 36 29 1

Intermolecular, Inc. 22 37 1

Sony Corporation 42 1 12 1 1

Elpida Memory, Inc. 24 29

Spansion Llc 35 1 8

Renesas Electronics Corporation 22 21

Sharp 30 9 2 1

Stmicroelectronics Inc. 12 28 1 1

Adesto Technologies 11 18 2

Crossbar, Inc. 21 1 8

Industrial Technology Research Institute

10 13 1 2 4

Infineon Technologies 19 7 1 1 1

Axon Technologies 27

Assignee vs. Claimed Metal Oxide ReRAM material

3/21/2014 13

Current Assignee (blank) perovskite crystal structure (e.g. PCMO, SrZrO3, LaNiO3)

tantalum oxide

nickel oxide

titanium oxide

hafnium oxide

copper oxide

iron oxide

aluminum oxide

zirconium oxide

vanadium oxide

ZnMnO tungsten oxide

NiCoO magnesium oxide

tin oxide Grand Total

Panasonic Corporation 37 9 2 3 51

Intermolecular, Inc. 30 2 2 2 1 37

Samsung Electronics Co., Ltd. 28 1 3 2 34

Xenogenic Development LLC 1 28 29

Unity Semiconductor Corporation 23 1 24

Sandisk 3d Llc 15 1 1 1 1 19

Toshiba 17 17

Macronix International Co. Ltd. 11 1 12

International Business Machines 7 2 1 10

Sharp 7 1 1 9

Micron Technology, Inc. 8 1 9

Fujitsu Limited 5 1 1 7

4d-s Ltd. 5 5

Hynix Semiconductor Inc 5 5

National Institute Of Advanced Industrial Science And Technology 3 1 4

Winbond Electronics Corp. 2 2 4

Nec Corporation 2 1 1 4

Hewlett-packard Company 3 3

Assignee vs. Claimed Silicon-Based ReRAM Material

3/21/2014 14

Current Assignee (blank) silicon-carbon alloy

silicon oxide

silicon carbide

doped polysilicon

crystalline silicon

amorphous silicon

Grand Total

Crossbar, Inc. 8 8

Dow Corning Corporation 4 4

Toshiba 1 1 2

British Telecommunications Public Limited Company 2 2

National University Corporation Tokyo University Of Agriculture And Technology 1 1

British Petroleum Company P.l.c., The 1 1

National Institute Of Advanced Industrial Science And Technology 1 1

Nxp B.v. 1 1

Callahan Cellular L.l.c. 1 1

Qimonda Ag 1 1

Semiconductor Energy Laboratory Co., Ltd. 1 1

Energy Conversion Devices, Inc. 1 1

University Of Michigan 1 1


Matsushita Electric Industrial Co., Ltd. 1 1

Grand Total 5 1 5 1 1 1 13 27

Assignee vs. Claimed Carbon-Based ReRAM Material

3/21/2014 15

Current Assignee (blank) nanotube graphene Grand Total

Sandisk 3d Llc 11 7 2 20


Toshiba 3 1 4


Energy Conversion Devices, Inc. 1 1

Industry-university Cooperation Foundation 1 1

Symetrix Corporation 1 1

Infineon Technologies 1 1

Samsung Electronics Co., Ltd. 1 1

Lockheed Martin Corporation 1 1

Stmicroelectronics Inc. 1 1

Applied Materials, Inc. 1 1

The Invention Science Fund I, Llc 1 1

Hynix Semiconductor Inc 1 1

Rising Silicon, Inc. 1 1

Qimonda Ag 1 1

Grand Total 24 13 7 44

Assignee vs. Claimed Application

3/21/2014 16

Current Assignee memory manufacturing process logic/computation 3D stacking neuromorphic 3-terminal device encoder/decoder/mux

Samsung Electronics Co., Ltd. 480 100 1 4 2


Toshiba 273 7 1 4

Ovonyx, Inc. 184 36 12 3 2 3

Macronix International Co. Ltd. 170 60 1 3

International Business Machines 126 46 4 2 6 5

Hynix Semiconductor Inc 128 32 1

Sandisk 3d Llc 99 34 15

Qimonda Ag 137 4 3

Hewlett-packard Company 80 12 13 4 3 5 10

Panasonic Corporation 110 10 1

Seagate Technology 99 6 1

Unity Semiconductor Corporation 93 7 1 1 2

Intel Corporation 64 14 2 1

Round Rock Research, Llc 44 29

Xenogenic Development LLC 34 28 3 1

Intermolecular, Inc. 24 33

Sony Corporation 56 1

Elpida Memory, Inc. 51 2

Spansion Llc 36 6

Renesas Electronics Corporation 42 1

Sharp 39 3

Stmicroelectronics Inc. 28 12 1

Adesto Technologies 25 4 1

Crossbar, Inc. 16 14

Industrial Technology Research Institute 27 3

Infineon Technologies 28 1

Axon Technologies 22 1 1

Samsung - Overview

• Top US patent holder overall for resistance switching materials (587 patents since 2003)

• Possesses patent for almost every resistance switching material type (phase change, metal oxide, CBRAM, molecular/polymer) with a primary interest in PCRAM (275 US patents) and a secondary interest in metal oxide ReRAM (34 patents). Several molecular resistance switching patents were obtained from Hewlett-Packard.

• Some variations of nickel oxide and copper oxide ReRAM have been patented by Samsung.

• Primary application focus is on alternative solution to non-volatile memory.

3/21/2014 17

Samsung – Patent Distribution for Resistance Switching Materials

3/21/2014 18

Count of US patents Patent Year

Claimed resistance switching material 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

phase change 1 2 8 19 20 41 40 54 40 35 13 2 275

(blank) 1 2 3 3 9 22 36 57 67 48 7 255

metal oxide 1 2 4 7 10 4 6 34

copper oxide 1 1 2

nickel oxide 1 1 1 3

perovskite crystal structure (e.g. PCMO, SrZrO3, LaNiO3) 1 1

(blank) 1 2 3 6 9 3 4 28

molecular/polymer 3 5 1 1 1 11

ionic/electrolytic (e.g. metal doped chalcogenide, CBRAM) 1 1 1 1 2 6

organic 1 1 1 1 4

carbon 1 1

nanotube 1 1

nanoparticles 1 1

Grand Total 5 9 9 22 24 53 69 99 110 108 70 9 587


Samsung – Patent Distribution for Resistance Switching Applications

3/21/2014 19


Claimed Application 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

memory 2 8 9 20 24 43 55 83 92 81 52 9 478

manufacturing process 3 1 2 10 13 13 16 26 16 100

3D stacking 1 3 4

3-terminal device 1 1 2

test circuit 1 1

digital-to-analog converter 1 1

logic/computation 1 1

Grand Total 5 9 9 22 24 53 69 99 110 108 70 9 587

Samsung – Key US Patents for Resistance Switching Devices

US Patent Number

Patent Claim Comments

6456525 A data storage device comprising a resistive cross point array of memory cells, each memory cell including a memory element; and a linear resistive element connected in series with the memory element.

Assignment transferred to Samsung from Hewlett Packard; a similar resistive cross point array was disclosed in 1987 by CalTech researchers in US Patent 4839859 (not considered during the patent examination).

7417271 An electrode structure, comprising: a lower electrode; a first oxide layer formed on the lower electrode, wherein the first oxide layer is formed of an oxide having a variable oxidation state; a second oxide layer formed on the first oxide layer; and an upper electrode formed on the second oxide layer, wherein at least one of the first and second oxide layers are formed of a resistance-varying material.

Claims a bilayer metal oxide ReRAM cell similar to that popularized in the paper “The missing memristor found” written by researchers owned by Hewlett-Packard. An earlier patent from Sharp (US6972238) describes a similar structure (not considered during the patent examination).

8456889 A semiconductor device, comprising: a variable resistance layer; a gate insulating layer on the variable resistance layer; and a gate on the gate insulating layer, the gate being configured to induce a channel region, the channel region including the variable resistance layer.

Appears to include basic claims to a 3-terminal field effect transistor structure including variable resistance material in the channel. Similar to US Patent 4839700 from Caltech (not considered during the patent examination)

See http://tinytechip.blogspot.com/search?q=memory+resistor+patent+thicket for a further review of potentially invalid ReRAM and related patents 3/21/2014 20

http://tinytechip.blogspot.com/search?q=memory+resistor+patent+thicket



Micron - Overview

• 490 US patents for resistance switching materials since 2003

• Patents are almost equally divided between PCRAM (phase change) with 112 patents and CBRAM with 132 patents along with a few recent carbon-based ReRAM patents

• Several PCRAM patents originally assigned to Intel and STMicroelectronics are now assigned to Micron

• Primary application focus is on alternative solution to non-volatile memory

3/21/2014 21

Micron – Patent Distribution for Resistance Switching Materials

3/21/2014 22




(blank) 11 11 16 23 19 15 16 17 20 28 51 6 233

ionic/electrolytic (e.g. metal doped chalcogenide, CBRAM) 3 14 19 21 15 21 8 12 6 5 5 2 131

phase change 4 5 3 5 4 4 3 16 17 25 19 6 111

metal oxide 1 1 4 2 1 9

titanium oxide 1 1

(blank) 1 1 4 2 8

carbon 2 1 1 1 5

graphene 1 1 2

(blank) 2 1 3

molecular/polymer 1 1

Grand Total 18 30 39 49 40 40 29 45 44 62 78 16 490

Micron – Patent Distribution for Resistance Switching Applications

3/21/2014 23



memory 11 17 24 33 30 20 25 35 35 38 52 13 333

manufacturing process 7 13 15 16 10 20 4 10 9 24 25 3 156

encoder/decoder/mux 1 1

Grand Total 18 30 39 49 40 40 29 45 44 62 78 16 490

Micron – Key US Patents for Resistance Switching Devices

US Patent Number


6891749 A memory element comprising: a resistance variable material; and first and second electrodes connected to said resistance variable material, said first and second electrodes comprising materials capable of stabilizing said element in a low resistance state.

The resistance switching memory cell is taught to be stabilized by having electrodes with different electrochemical potential. A similar concept was earlier described in an a patent assigned to AMD (US6781868).

7700485 A method of forming a resistance variable material, comprising: plating a metal material onto a chalcogenide material; and diffusing metal ions from the metal material into the chalcogenide material to form a resistance variable material.

Relatively early priority date (2001) for a basic method of manufacturing CBRAM/ programmable metallization cell devices.

8345478 A memory device comprising: an array of transistor-based non-volatile memory having emerging non-volatile memory for storing programming data into the array using sense circuitry.

Surprisingly broad claims for using ReRAM or PCRAM (i.e. “emerging non-volatile memory”) to reduce the amount of sense circuitry required for Flash memory transistor arrays.

3/21/2014 24 See http://tinytechip.blogspot.com/search?q=memory+resistor+patent+thicket for a further review of potentially invalid ReRAM and related patents




Toshiba - Overview

• 286 US patents for resistance switching materials since 2003 with 100 issued in 2013 alone

• Most of Toshiba’s patents are not limited to a specific resistance switch type but PCRAM, metal oxide ReRAM, and CBRAM variations are included with some focus on carbon-based ReRAM

• Primary application focus is on alternative solution to non-volatile memory with an emphasis on 3D stacking solutions

3/21/2014 25

Toshiba – Patent Distribution for Resistance Switching Materials

3/21/2014 26



Claimed resistance switching material 2004 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

(blank) 3 4 5 16 55 70 84 6 243

metal oxide 2 8 1 6 17

(blank) 2 8 1 6 17

phase change 1 1 3 4 1 5 15

ionic/electrolytic (e.g. metal doped chalcogenide, CBRAM) 1 2 1 4

carbon 1 1 2 4

nanotube 1 1

(blank) 1 2 3

silicon 1 1 2

silicon oxide 1 1

(blank) 1 1

nanoparticles 1 1

Grand Total 1 3 8 5 29 61 73 100 6 286

Toshiba – Patent Distribution for Resistance Switching Applications

3/21/2014 27


Claimed Application 2004 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

memory 1 3 8 4 26 58 70 97 6 273

manufacturing process 1 2 2 2 7

3D stacking 1 1 1 1 4

test circuit 1 1


Grand Total 1 3 8 5 29 61 73 100 6 286

Toshiba – Key US Patents for Resistance Switching Devices

US Patent Number


7606059 A programmable resistance memory device comprising: a semiconductor substrate; at least one cell array, formed above said semiconductor substrate, which comprises a plurality of bit lines arranged in parallel with each other, a plurality of word lines arranged in parallel with each other in such a direction as crossing said bit lines, and memory cells connected between the bit lines and the word lines at cross portions of the bit lines and the word lines, each said memory cell having a stack structure of a programmable resistance element and an access element, said programmable resistance element and an access element, said programmable resistance element being applied a voltage greater than a certain threshold to develop a high resistance state or a low resistance state and storing the high resistance state or the low resistance state in a non-volatile manner, said access element having a resistance value in an off-state that is ten times or more as high as that in a select state; and a read/write circuit formed on said semiconductor substrate as underlying said cell array and connected to the bit lines and word lines through vertical wirings for data reading and data writing in communication with said cell array.

Patent describes a type of 3D stacked ReRAM. A high number of forward citations (198) indicate this patent may have high technical importance.

8014188 An electric element, comprising: a pair of electrodes; and a plurality of powder-condensed and solidified carbon nanotubes of three-dimensional network structure which are located between the pair of electrodes.

Includes basic claims to a carbon-based form of ReRAM





Macronix - Overview


• Mostly focused on PCRAM (phase change) but some metal oxide and other forms of ReRAM devices are also patented

• Has partnered with IBM and Infineon in phase change memory development

• Primary application focus is on alternative solution to non-volatile memory with some focus on 3D stacking solutions

3/21/2014 29

Macronix – Patent Distribution for Resistance Switching Materials

3/21/2014 30




(blank) 1 2 4 5 4 10 20 14 24 29 13 126

phase change 2 4 5 5 11 11 14 23 11 7 1 94


(blank) 3 4 2 1 1 11

tungsten oxide 1 1

ionic/electrolytic (e.g. metal doped chalcogenide, CBRAM) 2 2

Grand Total 1 4 8 10 9 21 31 32 51 44 21 2 234

Macronix – Patent Distribution for Resistance Switching Applications

3/21/2014 31



memory 1 8 8 6 18 20 27 36 30 15 1 170

manufacturing process 4 2 3 3 11 5 15 12 4 1 60

3D stacking 2 1 3


Grand Total 1 4 8 10 9 21 31 32 51 44 21 2 234

Macronix – Key US Patents for Resistance Switching Devices

US Patent Number


6579760 A memory device, comprising: a substrate; a first plurality of conductive lines on the substrate extending in a first direction; a second plurality of conductive lines above the first plurality of conductive lines, and extending in second direction and crossing over the first plurality of conductive lines at intersections; a plurality of memory cells at said intersections and in electrical contact with the first and second pluralities of conductive lines, the memory cells comprising self-aligned structures including a selection device, and a phase change memory element.

Describes a self-alignment technique to achieve a smaller memory cell area for PCRAM. A very large number of forward citations (343) indicates a high technical importance.

7777215 A memory device comprising: a first electrode and a second electrode; a metal oxide resistive random access memory element and a buffer layer located between and electrically coupled to the first and the second electrodes, the memory element comprising one or more metal oxygen compounds; and the buffer layer comprising SiO2.

Describes improving data retention and cycle endurance for metal oxide ReRAM by including a SiO2 buffer layer.





Ovonyx - Overview


• Focused on PCRAM (phase change)

• Several patents (34) owned by Ovonyx were assigned from Energy Conversion Devices, a company formed by Stanford Ovshinsky who has been a major contributor to phase change material research since the 1960’s

• A few patents were obtained from Intel and STMicroelectronics

• Application focus includes programmable logic (12 patents) using phase change devices

3/21/2014 33

Ovonyx – Patent Distribution for Resistance Switching Materials

3/21/2014 34




phase change 9 9 15 12 10 19 11 17 18 17 11 2 150

(blank) 6 8 9 4 2 6 3 7 11 6 6 68

Grand Total 15 17 24 16 12 25 14 24 29 23 17 2 218

Ovonyx – Patent Distribution for Resistance Switching Applications

3/21/2014 35



memory 9 11 16 14 8 17 10 18 23 20 15 2 163


logic/computation 1 1 2 1 4 9

3D stacking 1 1 1 3

3-terminal device 1 1 1 3

error correction 1 1 2

ESD protection 1 1

Security device 1 1

neuromorphic 1 1

Grand Total 15 17 24 16 12 25 14 24 29 23 17 2 218

Ovonyx – Key US Patents for Resistance Switching Devices

US Patent Number


6087674 An electrically operated, single-cell memory element comprising: a volume of memory material comprising a heterogeneous mixture of a phase-change material and a dielectric material, said phase-change material programmable to a plurality of detectable resistivity values in response to an electrical signal, said dielectric material being between about 60 and 90 percent of said volume of memory material; and means for delivering said electrical signal to at least a portion of said volume of memory material.

Early patent originally from Energy Conversion Devices, has been cited 706 times by later patents indicating a high level of technical importance.

6987688 An integrated circuit chip, comprising: one or more electrically programmable phase-change memory elements; one or more latches electrically coupled to said phase-change memory elements; and a programmable logic device electrically coupled to said latches such that the states of said latches configure the logic of said programmable logic device.

A basic patent for a programmable logic device formed from phase change memory elements

7936593 An apparatus comprising: a first material having a first variation of an electrical characteristic with time; and a second material in electrical series with said first material, said second material having a second variation of said electrical characteristic with time, said second variation counteracting said first variation.

Teaches the use of a solid electrolyte oxide to counteract the variation of a phase change chalcogenide over time and increase memory stability and retention.

8228719 An apparatus, comprising: electronic circuitry integrated in a device; and a thin film electronic switching device configured to receive input signals from the electronic circuitry and to drive signals off the device, the thin film electronic switching device including a three-terminal ovonic threshold switch.

A basic patent for 3-terminal ovonic switch used in electronics.

3/21/2014 36 See http://tinytechip.blogspot.com/search?q=memory+resistor+patent+thicket for a further review of

potentially invalid ReRAM and related patents




IBM - Overview


• Mostly focused on PCRAM (phase change) but some metal oxide ReRAM (10) and CBRAM (4)

• 15 patents now owned by IBM were originally assigned to Macronix

• Application focus includes neuromorphic processing (6 patents) using phase change devices

3/21/2014 37

IBM – Patent Distribution for Resistance Switching Materials

3/21/2014 38


Claimed resistance switching material 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

phase change 1 4 1 8 14 11 22 18 27 4 110

(blank) 2 1 3 8 11 11 10 8 3 57


magnesium oxide 1 1


(blank) 1 3 1 2 7


nanoparticles 2 2

hydrogen 1 1 2

metal nitride 1 1 2

metal alloy 1 1

Grand Total 1 8 2 13 25 24 41 31 36 7 188

IBM – Patent Distribution for Resistance Switching Applications

3/21/2014 39


Claimed Application 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

memory 1 7 2 7 18 15 29 16 23 6 124

manufacturing process 1 6 5 6 9 11 7 1 46

neuromorphic 3 3 6


logic/computation 1 2 1 4

3D stacking 1 1 2

precision resistor 1 1

Grand Total 1 8 2 13 25 24 41 31 36 7 188

IBM – Key US Patents for Resistance Switching Devices

US Patent Number


7221579 A memory cell, comprising: a phase change material (PCM) element; and a heating element external to said PCM element, wherein said heating element causes one of a presence of and an absence of a phase boundary within said PCM element for storing information in said PCM element.

Describes improved switching speed obtained by an external heating element applied to a thin layer of phase change material.

7560721 A memory device comprising: a phase change memory cell; a first electrode; and a layer of filamentary resistor material positioned between the phase change memory cell and the first electrode, wherein at least one bistable conductive filamentary pathway is present in at least a portion of the layer of filamentary resistor material that provides electrical communication between the phase change memory cell to the first electrode.

Describes combining a phase change layer with a transition metal oxide material to provide filament formation to improve the high-to-low resistance ratio and the retention time.

8203873 A crosspoint architecture comprising: a plurality of electrodes; and a plurality of crossbar elements, each crossbar element disposed between a first and a second electrode in said plurality of electrodes, and each crossbar element comprising at least an asymmetrically programmed memory material used as a rectifier in series with a resistive memory node, said rectifier, in an ON state, supplying an ultrahigh current density that is greater than 106 A/cm2.

Describes obtaining a high-to-low resistance ratio >10000 and a high current density while using a solid electrolyte material having a rectifying diode effect.






SK Hynix - Overview


• Mostly focused on PCRAM (phase change) but some metal oxide ReRAM (5)


3/21/2014 41

SK Hynix – Patent Distribution for Resistance Switching Materials

3/21/2014 42




phase change 4 3 3 4 18 29 29 34 1 125

(blank) 1 2 3 6 19 2 33

metal oxide 1 1 3 5

carbon 1 1

nanotube 1 1


Grand Total 1 4 3 3 4 21 34 36 56 3 165

SK Hynix – Patent Distribution for Resistance Switching Applications

3/21/2014 43


Claimed Application 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

memory 1 4 3 2 4 17 30 22 42 3 128

manufacturing process 1 4 4 9 14 32

test circuit 2 2

reference voltage circuit 1 1

3-terminal device 1 1

electromagnetic/radio wave (e.g. RFID) 1 1

Grand Total 1 4 3 3 4 21 34 36 56 3 165

SK Hynix – Key US Patents for Resistance Switching Devices

US Patent Number


8422282 A phase change memory apparatus comprising: a plurality of row control cells; and a plurality of phase change memory cells formed on the row control cells while being electrically connected to the row control cells, wherein the plurality of row control cells and the plurality of phase change memory cells are vertically stacked in a cell array area.

Claims a vertical stacking solution for PCRAM to improve integration density.






Sandisk- Overview


• Patents covering PCRAM (phase change), metal oxide ReRAM, and carbon-based ReRAM

• Primary application focus is on alternative solution to non-volatile memory including a strong patent position in 3D stacking of ReRAM

3/21/2014 45

Sandisk– Patent Distribution for Resistance Switching Materials

3/21/2014 46



Claimed resistance switching material 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

(blank) 3 5 6 13 15 27 26 5 100

carbon 2 5 3 10 20

graphene 1 1 2

nanotube 2 2 3 7

(blank) 2 2 1 6 11


hafnium oxide 1 1

NiCoO 1 1


ZnMnO 1 1

(blank) 6 2 2 4 1 15

phase change 2 2 2 1 7

metal nitride 2 2

titanium alloy 1 1

Grand Total 3 7 6 27 22 35 42 7 149

Sandisk– Patent Distribution for Resistance Switching Applications

3/21/2014 47


claimed application 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

memory 2 6 6 24 15 21 19 6 99


3D stacking 1 1 1 3 1 7 1 15

voltage reference 1 1

Grand Total 3 7 6 27 22 35 42 7 149

Sandisk– Key US Patents for Resistance Switching Devices

US Patent Number


8503215 A memory cell comprising: a steering element; and a non-volatile state change element coupled in series with the steering element, wherein the steering element and state change element are disposed in a vertically-oriented pillar.

Patent includes basic claims to ReRAM cells including a steering element (e.g. diode) vertically aligned with the resistance switching material. Priority goes back to 1998.

8507315 A method of forming a memory cell, the method comprising: forming a steering element above a substrate; and forming a reversible resistance-switching element coupled to the steering element, wherein: the reversible resistance-switching element comprises one or more of TiOx, Ta2O5, Nb2O5, Al2O3, HfO2, and V2O5, and the reversible resistance switching element is formed without being etched.

Patent describes simplifying the manufacturing of metal oxide ReRAM.

8536015 A method of forming a metal-insulator-metal (“MIM”) stack, the method comprising: forming a first conducting layer; forming a resistivity-switching carbon-based material above the first conducting layer; and forming a second conducting layer above the carbon-based material, wherein the carbon-based material has a thickness of not more than ten atomic layers.

Patent includes basic claims to manufacturing carbon-based ReRAM






Qimonda - Overview


• Mostly focused on PCRAM (phase change)

• Several patents have been reassigned to Qimonda from Infineon (43), IBM (8) and Macronix (4)


3/21/2014 49

Qimonda – Patent Distribution for Resistance Switching Materials

3/21/2014 50




(blank) 1 6 18 20 26 18 7 2 98

phase change 2 1 7 4 11 9 4 1 39

ionic/electrolytic (e.g. metal doped chalcogenide, CBRAM) 1 2 3

nanoparticles 1 1

silicon 1 1

(blank) 1 1

metal oxide 1 1

carbon 1 1

(blank) 1 1


Grand Total 3 9 29 24 37 29 11 3 145

Qimonda – Patent Distribution for Resistance Switching Applications

3/21/2014 51


Claimed Application 2006 2007 2008 2009 2010 2011 2012 2013 Grand Total

memory 3 9 29 23 33 27 10 3 137

manufacturing process 1 2 1 4

3-terminal device 1 2 3

switch 1 1

Grand Total 3 9 29 24 37 29 11 3 145

Qimonda – Key US Patents for Resistance Switching Devices

US Patent Number


7214958 A memory cell device comprising: a first electrode; phase-change material adjacent the first electrode; a second electrode adjacent the phase-change material; a diffusion barrier adjacent the phase-change material; and isolation material adjacent the diffusion barrier for thermally isolating the phase-change material, wherein the diffusion barrier prevents diffusion of the phase-change material into the isolation material, wherein the isolation material comprises a dielectric material that limits the heat leakage from the phase change material, and wherein the dielectric material comprises a porous oxide film having a thermal conductivity between 0.1 and 0.8 W/mk.

This patent has been cited 214 times by later patents indicating a high level of technical importance.

7679980 A memory comprising: an array of phase change memory cells; and a first circuit for refreshing only memory cells within the array of phase change memory cells that are programmed to non-crystalline states in response to a request for a refresh operation.

Patent describes reducing the temperature accumulation in PCRAM by reducing the number of refresh operations per memory cell.

8059446 An integrated circuit having a memory cell, the memory cell comprising: a programmable resistivity layer; a writing line; and a switch arranged between the resistivity layer and the writing line, the switch comprising a control input connected to a select line, the switch limiting a current through the resistivity layer for a write operation.

Patent describes a transistor in series with a programmable resistivity layer to limit current during data writing.






Hewlett-Packard - Overview


• Originally focused on molecular resistance switching but now focusing on metal oxide systems

• Often claim their form of ReRAM using an old circuit theory concept of a “memristor” which HP has popularized in recent years but the memristor theory is a technically incorrect circuit model for ReRAM1

• Has patented in logic/computational, neouromorphic, and various other application areas

3/21/2014 53

1P. Meuffels, R. Soni, “Fundamental issues and Problems in the Realization of Memristors,” 31 July 2012, arXiv:1207.7319

Hewlett-Packard – Patent Distribution for Resistance Switching Materials

3/21/2014 54




(blank) 3 1 9 2 12 9 1 2 7 9 26 1 82

molecular/polymer 5 3 9 2 2 1 1 23

ionic/electrolytic (e.g. metal doped chalcogenide, CBRAM) 1 3 5 4 13

phase change 2 1 2 1 1 7

metal oxide 1 2 3

carbon 2 1 3

graphene 2 1 3

nanoparticles 1 1 1 3

silicon 1 1

crystalline silicon 1 1

Grand Total 10 5 20 6 14 10 1 3 12 18 35 1 135

Hewlett-Packard – Patent Distribution for Resistance Switching Applications

3/21/2014 55


Row Labels 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

memory 9 2 11 4 6 3 2 4 13 25 79

logic/computation 1 3 1 4 2 1 1 13

manufacturing process 1 5 1 2 1 1 1 12

encoder/decoder/mux 1 2 3 1 2 9


3D stacking 2 2 4

neuromorphic 1 1 1 3

electromagnetic/radio wave (e.g. RFID) 2 2

display (e.g. LCD) 1 1

protection circuit 1 1

packaging 1 1

waveguide 1 1

switch 1 1

frequency source 1 1

light sensor 1 1

negative differential resistance 1 1

Grand Total 10 5 20 6 14 10 1 3 12 18 35 1 135

Hewlett-Packard – Key US Patents for Resistance Switching Devices

US Patent Number


6128214 A two-dimensional memory array comprising a plurality of nanometer-scale devices, each device comprising a junction formed by a pair of crossed wires where one wire crosses another and at least one connector species comprising at least one bi-stable molecular switch and connecting said pair of crossed wires in said junction, said junction having a functional dimension in nanometers, wherein said at least one connector species and said pair of crossed wires form an electrochemical cell, with one set of wires formed above another set of wires.

This patent was cited 669 times by later patents indicating technical importance to molecular switching types of ReRAM.

6891744 A device comprising an electrode-insulator-electrode and selected from the group consisting of metal-insulator-metal, metal-insulator-semiconductor, and semiconductor-insulator-semiconductor, wherein each said electrode comprises a nanoscale line and wherein said insulator comprises a solid layer of configurable material between each said electrode.

Includes basic claims covering a nanoscale crossbar ReRAM architecture. Many earlier crossbar structures were known for resistance switching (e.g. US Patent 3445823, US Patent 4677742) and it would have been arguably obvious to reduce the wire dimensions using nanolithography or e-beam lithography (e.g. US Patent 5772905).

7203789 An architecture for computing, comprising: nanometer scale crossbar switches configured to perform a logical function in response to a sequence of pulses that encode logic values in the nanometer scale crossbar switches as impedances, wherein input data is latched at input latches within the nanometer scale crossbar switches and wire-AND junctions are open/closed with the result being driven out of an output latch.

Describes a computing system based on nanoscale resistance switch crossbars.






Panasonic - Overview


• Mostly focused on metal oxide ReRAM particularly tantalum oxide based


3/21/2014 57

Panasonic – Patent Distribution for Resistance Switching Materials

3/21/2014 58




(blank) 2 4 4 7 21 27 1 66

metal oxide 4 8 11 28 51

hafnium oxide 1 1 2

iron oxide 3 3

tantalum oxide 3 3 3 9

(blank) 1 5 7 24 37

phase change 1 1 2

metal nitride 1 1

nanoparticles 1 1

Grand Total 1 2 4 10 15 33 55 1 121

Panasonic – Patent Distribution for Resistance Switching Applications

3/21/2014 59


Claimed Application 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

memory 1 2 4 10 14 33 45 1 110

manufacturing process 1 9 10


Grand Total 1 2 4 10 15 33 55 1 121

Panasonic – Key US Patents for Resistance Switching Devices

US Patent Number


7577022 An electric element, comprising: a first electrode; a second electrode; and a layer connected between the first electrode and the second electrode and having a diode characteristic and a variable resistance characteristic, wherein the layer conducts a substantial electric current in a forward direction extending from one of the first electrode and the second electrode to the other electrode as compared to a reverse direction opposite of the forward direction, and the resistance value of the layer for the forward direction increases or decreases according to a predetermined pulse voltage applied between the first electrode and the second electrode.

Patent describes a memory resistance cell having both variable resistance and diode characteristics. This was earlier described by US Patent 4646266 from Energy Conversion Devices, US Patent 6891749 from Micron, and US Patent 7157732 from Spansion.

8022502 A nonvolatile memory element comprising: a first electrode; a second electrode; and a resistance variable layer which is disposed between the first electrode and the second electrode, a resistance value of the resistance variable layer varying reversibly according to electric signals having different polarities which are applied between the electrodes; wherein the resistance variable layer has a first region comprising a first oxygen-deficient tantalum oxide having a composition represented by TaOx (0<x<2.5) and a second region comprising a second oxygen-deficient tantalum oxide having a composition represented by TaOy (x<y<2.5), the first region and the second region being arranged in a thickness direction of the resistance variable layer.

Claims a form of ReRAM based on tantalum oxide which is described to not need a forming process and has a high speed and reversibly stable rewrite characteristic.






Sharp/Xenogenic - Overview


• 66 of the 108 patents were originally assigned to Sharp but are currently assigned to “Xenogenic LLC” assumed to be a licensing or development company for Sharp

• Focus on metal oxides, primarily perovskites (e.g. PCMO, SrZrO3, LaNiO3)


3/21/2014 61

Sharp/Xenogenic – Patent Distribution for Resistance Switching Materials

3/21/2014 62




(blank) 1 8 10 9 4 6 5 7 5 9 2 66

metal oxide 1 4 5 8 5 4 2 2 1 6 38

perovskite crystal structure (e.g. PCMO, SrZrO3, LaNiO3) 1 4 5 8 5 4 1 1 29

titanium oxide 1 1

(blank) 1 1 6 8

nanoparticles 2 1 3

metal nitride 1 1

Grand Total 1 5 13 18 14 10 8 8 9 5 15 2 108

Sharp/Xenogenic – Patent Distribution for Resistance Switching Applications

3/21/2014 63



memory 2 7 11 7 4 6 7 8 5 14 2 73


3D stacking 1 2 3

neuromorphic 1 1

Grand Total 1 5 13 18 14 10 8 8 9 5 15 2 108

Sharp/Xenogenic – Key US Patents for Resistance Switching Devices

US Patent Number


6531371 A method of manufacturing a resistive memory structure comprising the steps of: a) providing a semiconductor substrate; b) forming a plurality of bottom electrodes; c) depositing a layer of perovskite material overlying the bottom electrodes; d) removing the layer of perovskite material from regions outside a memory array area and leaving perovskite material intact within the memory array area, whereby the layer of perovskite material remains over more than one bottom electrode; and e) forming a plurality of top electrodes overlying the layer of perovskite material.

Basic patent for fabricating metal oxide ReRAM based on oxides with a perovskite crystal structure.

6673691 A method of changing the resistance of a perovskite metal oxide thin film device with a resistance-change-producing pulse comprising changing the resistance of the device by varying the duration of a resistance-change-producing pulse.

Basic patent for setting the resistance of a metal oxide ReRAM based on oxides with a perovskite crystal structure using pulse width modulation.

7148533 A memory resistance film with controlled oxygen content, the film comprising: an oxygen-deficient manganite region; and, an oxygen-rich manganite region, adjacent the oxygen-deficient manganite region.

Patent describes bilayer oxide ReRAM to improve the high to low resistance change ratio.






Seagate - Overview


• Focus on CBRAM and PCRAM materials


3/21/2014 65

Seagate – Patent Distribution for Resistance Switching Materials

3/21/2014 66



Claimed resistance switching material 2010 2011 2012 2013 2014 Grand Total

(blank) 9 38 24 13 1 85


phase change 2 2 4

metal oxide 1 1


porous 1 1

Grand Total 15 42 30 18 1 106

Seagate – Patent Distribution for Resistance Switching Applications

3/21/2014 67


Claimed Application 2010 2011 2012 2013 2014 Grand Total

memory 14 41 28 15 1 99


3D stacking 1 1

Grand Total 15 42 30 18 1 106

Seagate – Key US Patents for Resistance Switching Devices

US Patent Number


8097874 A programmable metallization memory cell comprising: an electrochemically active electrode and an inert electrode, the electrochemically active electrode comprising silver filament forming metal; an ion conductor solid electrolyte material between the electrochemically active electrode and the inert electrode; and a sacrificial metal disposed between the electrochemically active electrode and the inert electrode, the sacrificial metal having a more negative standard electrode potential than the silver filament forming metal and the sacrificial metal comprising nickel or chromium.

Patent has been cited 17 times by more recent patents indicating a relative technical importance in comparison to other ReRAM patents from Seagate.






Intel - Overview


• Focus on PCRAM materials


3/21/2014 69

Intel – Patent Distribution for Resistance Switching Materials

3/21/2014 70




phase change 6 5 1 3 9 5 6 7 11 6 7 2 68

(blank) 1 2 1 1 1 1 4 11


Grand Total 7 7 1 4 10 5 7 7 13 6 11 2 80

Intel – Patent Distribution for Resistance Switching Applications

3/21/2014 71


claimed application 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

memory 7 4 1 3 5 3 7 6 10 6 10 1 63

manufacturing process 2 1 4 2 1 3 1 14

3D stacking 1 1 2

3-terminal device 1 1

Grand Total 7 7 1 4 10 5 7 7 13 6 11 2 80

Intel – Key US Patents for Resistance Switching Devices

US Patent Number


6512241 A phase change memory comprising: an electrode on said substrate, said electrode having a substantially planer surface with a closed geometric shape; a layer covering substantially all of the closed geometric shape with the exception of an exposed portion; and a phase change material contacting said exposed portion.

This patent was cited by 520 later patents indicating a high level of technical importance. Describes reducing the size of the lower electrode for more effective heating.

6576921 A memory comprising: a phase change memory element including a first and second node; a bipolar transistor coupled to said first node; and a N-channel field effect transistor coupled to said bipolar transistor.

This patent was cited by 223 later patents indicating a high level of technical importance. Describes coupling an N-channel field effect transistor to a bipolar transistor of a phase change memory element to minimize leakage current.






Sony - Overview


• Focus on CBRAM materials


3/21/2014 73

Sony – Patent Distribution for Resistance Switching Materials

3/21/2014 74




(blank) 4 5 5 2 3 1 8 14 42


organic 1 1


Grand Total 4 6 5 3 7 2 8 21 56

Sony – Patent Distribution for Resistance Switching Applications

3/21/2014 75



memory 4 5 5 3 7 2 8 21 55


Grand Total 4 6 5 3 7 2 8 21 56

Sony – Key US Patents for Resistance Switching Devices

US Patent Number


7307270 A memory element comprising: a memory layer and an ion source layer positioned between first and second electrodes, wherein said ion source layer contains any of elements selected from Cu, Ag and Zn, and any of elements selected from Te, S and Se, and said memory layer is made of any of tantalum oxide, niobium oxide, aluminum oxide, hafnium oxide and zirconium oxide, or is made of mixed materials thereof.

Patent describes a metal oxide ReRAM including an ion source layer to maintain a high off state resistance with thin films <10nm.






Elpida - Overview


• Focus on PCRAM materials


3/21/2014 77

Elpida – Patent Distribution for Resistance Switching Materials

3/21/2014 78



Claimed resistance switching material 2008 2009 2010 2011 2012 2013 2014 Grand Total

phase change 1 6 11 6 1 3 1 29

(blank) 2 5 5 6 6 24

Grand Total 3 11 16 12 7 3 1 53

Elpida – Patent Distribution for Resistance Switching Applications

3/21/2014 79


claimed application 2008 2009 2010 2011 2012 2013 2014 Grand Total

memory 3 11 16 10 7 3 1 51

manufacturing process 2 2

Grand Total 3 11 16 12 7 3 1 53

Elpida – Key US Patents for Resistance Switching Devices

US Patent Number


7502252 A nonvolatile semiconductor memory device comprising: first and second regions formed in parallel to each other to define a first channel region therebetween; a first word line formed over the first channel region with an intervention of a first gate insulating film therebetween, the first word line extending in a first direction; a first bit line extending in a second direction crossing the first direction, the first bit line crossing over the first and second regions and the first word line and having an electrical contact with the first region; a plurality of first element select lines extending in parallel to each other in the second direction, each of the first element select lines crossing over the first and second regions and the first word line; and a plurality of first memory elements, each of the first memory elements being disposed at an intersection of an associated one of the first element select lines and the second region and having electrical contacts with the associated one of the first element select lines and the second region.

This patent was cited 42 times by later patents indicating a relatively higher technical importance than other patents from Elpida.






Spansion - Overview


• Focus on polymeric resistance switching materials


3/21/2014 81

Spansion – Patent Distribution for Resistance Switching Materials

3/21/2014 82




(blank) 2 2 4 4 4 7 8 3 1 35

molecular/polymer 2 2 1 2 1 8

metal oxide 1 1

Grand Total 2 4 4 6 5 4 7 8 3 1 44

Spansion – Patent Distribution for Resistance Switching Applications

3/21/2014 83


claimed application 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Grand Total

memory 1 3 3 5 5 3 6 6 3 1 36

manufacturing process 1 1 1 1 1 1 6

test circuit 1 1

temperature compensation 1 1

Grand Total 2 4 4 6 5 4 7 8 3 1 44

Spansion – Key US Patents for Resistance Switching Devices

US Patent Number


7706168 A method for forming a resistive memory device which has a first resistance in an erased state, the method comprising providing that the memory device has in the erased state a second resistance different from the first resistance.

The patent describes using an annealing step during manufacture to increase the off state resistance of a ReRAM material.

7835172 A semiconductor device comprising: a data storage element having a variable resistance and an electrode; and a controller that selects between a first mode that stores data by a resistance value of the variable resistance, and a second mode that stores data by an amount of electrical charge stored in the electrode.

The patent describes controlling a memory cell to operate in either as ReRAM in a non-volatile mode or as DRAM in a volatile mode.

8289750 A semiconductor device comprising: a plurality of first memory cells arranged in a first memory layer, the first memory cells comprising a plurality of selection transistors and a plurality of variable resistance elements; a plurality of second memory cells arranged in a plurality of second memory layers, the plurality of second memory cells comprising a plurality of selection diodes and a plurality of variable resistance elements; wherein the plurality of first memory cells are configured to store data when reliable storage is desirable; and further wherein the plurality of second memory cells are configured to store data when large storage volume is desirable.

Describes an ReRAM arrangement using transistor selection elements in a first memory array for storing data reliably and diode selection elements in another memory array for storing data in high density.






Unity Semiconductor - Overview


• Focus on metal oxide resistance switching materials

• Acquired by Rambus in February 2012


3/21/2014 85

Unity Semiconductor – Patent Distribution for Resistance Switching

Materials

3/21/2014 86



Claimed resistance switching material 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

(blank) 5 11 18 4 12 3 5 8 6 4 1 77

metal oxide 1 3 1 1 1 3 8 2 4 24

tin oxide 1 1

(blank) 1 3 1 1 1 3 8 1 4 23


Grand Total 5 12 21 5 13 5 8 17 9 8 1 104

Unity Semiconductor – Patent Distribution for Resistance Switching

Applications

3/21/2014 87


claimed application 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Grand Total

memory 4 10 21 3 12 5 6 16 9 6 1 93

manufacturing process 1 2 1 1 2 7

encoder/decoder/mux 1 1 2

3D stacking 1 1


Grand Total 5 12 21 5 13 5 8 17 9 8 1 104

Unity Semiconductor – Key US Patents for Resistance Switching Devices

US Patent Number


6753561 A cross point memory array comprising: a first group of substantially parallel conductive array lines; a second group of substantially parallel conductive array lines, oriented substantially perpendicular to the first group of parallel conductive lines; and a plurality of memory plugs located at the intersections of the first group of parallel conductive array lines and the second group of parallel conductive array lines, wherein each memory plug includes multiple layers of thin films including a thin film layer of a memory element that switches from a first resistance state to a second resistance state upon application of a first write voltage pulse to the memory element and reversibly switches from the second resistance state back to the first resistance state upon application of a second write voltage pulse to the memory element having opposite polarity of the first write voltage pulse; and at least one thin film layer constituting a non-ohmic device that, upon application of low magnitude voltages to the non-ohmic device, imparts a relatively high resistance to the memory plug.

This patent has been cited by later patents 229 times indicating a high level of technical importance.






Intermolecular - Overview


• Focus on metal oxide resistance switching materials

• Primary application focus is on manufacturing and testing ReRAM non-volatile memory

3/21/2014 89

Intermolecular– Patent Distribution for Resistance Switching Materials

3/21/2014 90



Claimed resistance switching material 2009 2010 2011 2012 2013 2014 Grand Total

metal oxide 1 2 4 11 17 2 37

aluminum oxide 1 1

hafnium oxide 1 1 2

nickel oxide 1 1 2

titanium oxide 1 1 2

(blank) 1 2 4 8 13 2 30

(blank) 2 4 12 4 22


Grand Total 1 2 7 15 29 6 60

Intermolecular – Patent Distribution for Resistance Switching Applications

3/21/2014 91


claimed application 2009 2010 2011 2012 2013 2014 Grand Total

manufacturing process 1 2 5 7 15 3 33

memory 2 7 13 2 24

test circuit 1 1 1 3

Grand Total 1 2 7 15 29 6 60

Intermolecular – Key US Patents for Resistance Switching Devices

US Patent Number


8648418 A non-volatile resistive switching memory element comprising: a first electrode; a metal oxide layer over the first electrode, wherein the metal oxide layer comprises a material having a bandgap greater than 4 eV, and non-metallic defect paths in localized regions of the metal oxide layer; and a second electrode of the metal oxide layer.

Patent describes higher bandgap metal oxide ReRAM for higher resistivity with dopants to improve retention and on/off current ratios.






Adesto - Overview


• Patents originally assigned to Qimonda (5) and Infineon (10) are currently assigned to Adesto.

• Focus on CBRAM resistance switching materials


3/21/2014 93

Adesto – Patent Distribution for Resistance Switching Materials

3/21/2014 94




ionic/electrolytic (e.g. metal doped chalcogenide, CBRAM) 1 1 2 4 1 4 3 2 18

(blank) 3 2 3 1 2 11

nanoparticles 1 1 2

Grand Total 4 3 6 6 1 4 3 4 31

Adesto – Patent Distribution for Resistance Switching Applications

3/21/2014 95



memory 3 3 5 4 3 3 4 25


voltage reference 1 1


Grand Total 4 3 6 6 1 4 3 4 31

Adesto – Key US Patents for Resistance Switching Devices

US Patent Number


7215568 A method for writing to a CBRAM resistance element of a resistive memory arrangement having a cell array structured in rows and columns with resistive memory cells connected to a drive element, each drive element jointly being connected to a plurality of CBRAM resistive elements forming a memory cell, the method comprising; opening a word line of a corresponding memory cell; placing all plate lines and bit lines of unselected resistance elements at a specific plate potential; increasing the plate line voltage of a selected resistance element by a specific write voltage; and decreasing the voltage of an associated bit line by the write voltage.

Highest forward citations of Adesto’s CBRAM patents (49) indicating relatively higher technical importance.

8426839 A conductive bridging memory cell, comprising: an ion conductor layer formed over an active electrode that is a source of conductive ions for the ion conductor layer; a conductive layer formed in a vertical opening in a lower insulating layer and a barrier layer; and the barrier layer is formed below the active electrode and in contact with the conductive layer, and formed on the top surface of the lower insulating layer, the barrier layer substantially preventing a movement of conductive ions therethrough.

A barrier layer is described to allow more control of electrical properties (e.g. resistances, switching thresholds) in CBRAM memory cell.






Crossbar - Overview


• Company formed based on research conducted at the University of Michigan on resistance switching in amorphous silicon.

• Current investors include Kleiner Perkins Caufield & Byers

• Focus on amorphous silicon resistance switching materials


3/21/2014 97

Crossbar – Patent Distribution for Resistance Switching Materials

3/21/2014 98



Claimed resistance switching material 2012 2013 2014 Grand Total

(blank) 5 12 4 21

silicon 2 5 1 8

amorphous silicon 2 5 1 8

metal oxide 1 1


Crossbar – Patent Distribution for Resistance Switching Applications

3/21/2014 99


claimed application 2012 2013 2014 Grand Total

memory 2 10 4 16

manufacturing process 5 8 1 14


Crossbar – Key US Patents for Resistance Switching Devices

US Patent Number


8088688 A method of forming a non-volatile memory device, comprising: providing a semiconductor substrate having a surface region; forming a first dielectric material overlying the surface region; forming a first wiring material comprising at least an aluminum material overlying the first dielectric material; forming a silicon material overlying the first wiring material; forming an intermix region using at least an anneal process, the intermix region consuming a portion of the silicon material and a portion of the aluminum material, the annealing process causing formation of a first alloy material from the intermix region and a polycrystalline silicon material having a p+ impurity characteristic overlying the first alloy material, the polycrystalline silicon material having the p+ impurity being derived from an aluminum species from the aluminum material and the silicon material; forming a first wiring structure from at least a portion of the first wiring material; forming a resistive switching element comprising an amorphous silicon material overlying the polycrystalline silicon material having the p+ impurity characteristic; and forming a second wiring structure comprising at least a metal material overlying the resistive switching element.

Claims method of forming amorphous silicon form of ReRAM






Axon - Overview


• Company formed based on research conducted at Arizona State University in the 1990’s

• Focus on CBRAM materials


3/21/2014 101

Axon – Patent Distribution for Resistance Switching Materials

3/21/2014 102




ionic/electrolytic (e.g. metal doped chalcogenide, CBRAM) 1 2 2 4 3 3 1 2 2 3 23

Grand Total 1 2 2 4 3 3 1 2 2 3 23

Axon – Patent Distribution for Resistance Switching Applications

3/21/2014 103


claimed application 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Grand Total

memory 1 2 1 3 3 2 1 2 2 3 20

photonics 1 1



Grand Total 1 2 2 4 3 3 1 2 2 3 23

Axon – Key US Patents for Resistance Switching Devices

US Patent Number


5761115 A programmable metallization cell comprising a body formed of a fast ion conductor material having metallic ions disposed therein, a plurality of conducting electrodes deposited on said body of material, said electrodes adapted to have a first voltage applied between two of said electrodes to program the cell by growing a metallic dendrite from the negative of the two electrodes toward the positive of the two electrodes while the first voltage is applied thereto.

Basic patent claim to programmable metallization cell/CBRAM technology, has been cited 506 times by later patents, estimated to expire May 30, 2016

7728322 A microelectronic programmable structure comprising: an insulating layer; an ion conductor comprising an oxide formed at least partially within a via in the insulating layer; a first electrode proximate the ion conductor; and a second electrode proximate the ion conductor.

Continuation patent estimated to expire May 30, 2016, it is notable that earlier ion conductor resistance switching materials based on oxides are known (US Patent 4945257, US Patent 5278636)






Contour Semiconductor - Overview



3/21/2014 105

Contour Semiconductor – Patent Distribution for Resistance Switching

Materials

3/21/2014 106



Claimed resistance switching material 2005 2008 2009 2010 2011 2012 2013 Grand Total

(blank) 1 1 3 2 3 3 13

phase change 1 1

Grand Total 1 1 1 3 2 3 3 14

Contour Semiconductor – Patent Distribution for Resistance Switching

Applications

3/21/2014 107


claimed application 2005 2008 2009 2010 2011 2012 2013 Grand Total

memory 1 1 2 2 2 2 10

encoder/decoder/mux 1 1 2

manufacturing process 1 1 2

Grand Total 1 1 1 3 2 3 3 14

Contour Semiconductor – Key US Patents for Resistance Switching

Devices US Patent Number


6956757 An electronic memory device comprising two or more layers of memory circuitry, each layer comprising circuitry for storing and facilitating retrieval of information and decoding circuitry for addressing specific information within said information storage circuitry, wherein said two or more layers are interconnected by conductors at least some of which are also connected to said decoding circuitry.

Includes broad claims which may be relevant to forming multilayer ReRAM on top of a CMOS substrate.

7826244 An electronic memory device comprising: a plurality of layers of memory circuitry, wherein each layer of memory circuitry comprises a plurality of storage locations; and error detection and correction logic interconnected to at least one of the layers of memory circuitry, wherein the error detection and correction logic is disposed on a substrate disposed beneath the plurality of layers of memory circuitry.


8116109 An electronic memory device comprising a plurality of layers of circuitry, wherein: a first layer comprises (i) storage circuitry for storing and facilitating retrieval of information and (ii) non-storage circuitry contributing to the access of the storage circuitry; and a substrate layer, disposed beneath the first layer, comprises a plurality of transistors which receive signals from the first layer.







4D-S - Overview


• Primary material for resistance switching is a perovskite-type metal oxide


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4D-S – Patent Distribution for Resistance Switching Materials

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Claimed resistance switching material 2011 2013 Grand Total

metal oxide 2 3 5

perovskite crystal structure (e.g. PCMO, SrZrO3, LaNiO3) 2 3 5

Grand Total 2 3 5

4D-S – Patent Distribution for Resistance Switching Applications

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claimed application 2011 2013 Grand Total

memory 2 1 3


Grand Total 2 3 5

4D-S – Key US Patents for Resistance Switching Devices

US Patent Number


7985960 A memory cell comprising: a plurality of crystals wherein the plurality of crystals comprise one of Praseodymium Calcium Manganese Oxide (PCMO) and or a chalcogenite material with similar Rex Cay MnO crystals; and at least two conductors, the at least two conductors being orthogonal to each other; wherein at least one of plurality of crystals are bounded by the orthogonal intersection of the at least two conductors.

It is not clear how the claims of this and related 4D-S patents overcome earlier patents based on PCMO resistance switching (e.g. US Patent 6531371) which were not considered during examination.






Symetrix - Overview



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Symetrix – Patent Distribution for Resistance Switching Materials

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Claimed resistance switching material 2009 2010 2011 Grand Total

(blank) 1 1 2

carbon 1 1

(blank) 1 1

Grand Total 1 1 1 3

Symetrix – Patent Distribution for Resistance Switching Applications

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claimed application 2009 2010 2011 Grand Total

memory 1 1 1 3

Grand Total 1 1 1 3

Symetrix – Key US Patents for Resistance Switching Devices

US Patent Number


7872900 A resistive switching integrated circuit memory comprising: a resistive switching memory cell including a correlated electron material (CEM); a write circuit for placing said resistive switching memory cell in a first resistive state or a second resistive state depending on information input into said memory, wherein the resistance of said CEM is higher in said second resistance state than in said first resistance state; and a read circuit for sensing the state of said memory cell and providing an electrical signal corresponding to the sensed state of said memory cell; wherein said memory is capable of being read 10

8 times with less than 50% fatigue.

Describes an alleged new type of resistance switching mechanism not requiring electroforming based on nickel oxide doped with extrinsic ligands.






Further Information

For a copy of the complete patent data used to generate this review send an e-mail to:

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with the subject “Resistance Switching Materials and Device Patent Landscape”

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