surface mems design project dr. lynn fuller, adam … mems design page 1 rochester institute of...

© October 16, 2016 Dr. Lynn Fuller

Surface MEMS Design

Rochester Institute of Technology

Microelectronic Engineering

ROCHESTER INSTITUTE OF TECHNOLOGYMICROELECTRONIC ENGINEERING

Surface MEMS Design Project

Dr. Lynn Fuller, Adam WardasWebpage: http://people.rit.edu/lffeee

Microelectronic EngineeringRochester Institute of Technology

82 Lomb Memorial DriveRochester, NY 14623-5604

Tel (585) 475-2035Email: [email protected]

Department webpage: http://www.microe.rit.edu

10-16-2016 SurfaceMEMsDesign.ppt

http://people.rit.edu/~lffeee

mailto:[email protected]

http://www.microe.rit.edu/


Surface MEMS Design



OUTLINE

IntroductionList of Possible MEMS DevicesKey EquationsDevice Cross SectionMEMS Switch ExampleMEMS Mirror ExampleDesign RulesPackagingMentor Graphics InstructionsMaskmakingStepper JobsFabrication DetailsSignal Processing Testing


Surface MEMS Design



INTRODUCTION

This document provides detailed information on RIT’s surface micromachine process. This process is capable of making many different types of MEMS devices. This MEMS fabrication process is CMOS compatible (with some modifications) back end module that can be added to realize compact microsystems (CMOS plus MEMS).


Surface MEMS Design



LIST OF MEMS DEVICES MADE WITH THIS PROCESS

Resistors – Micro BolometerHeaters – Chemical SensorsMicro Mirror - Two Axis MirrorThermally Actuated Two Arm CantileverChevron ActuatorsElectrostatic Comb DriveMEMS SwitchAccelerometerGas Flow Sensor, Anemometer, ThermionicLight ModulatorBio ProbesSpeakerHumidity SensorsPressure Sensors - MicrophoneTemperature Sensors – Thermopile, ResistorInductors, Capacitors – Humidity SensorHall Effect Sensors – other Magnetic Field Sensors


Surface MEMS Design



POSSIBLE NEW DEVICE – PROCESS MODIFICATIONS

Etch grooves in wafer to eliminate wafer sawing.

Nickel Metal for magnetic devices, instead of Aluminum?

Solder Bumps

Coils for Inductors

Tubes

Closed diaphragms for static pressure sensors

Spin Coat Polyimide to fill holes

Deposit or grow oxide to fill holes

Bimetallic actuators

Latching Chevron Actuators

Gears, Wheels, Rotary Structures

Folding Mirrors and Structures

Different Drop Cast Materials

Valves and Pumps


Surface MEMS Design



POSSIBLE NEW DEVICE – PROCESS MODIFICATIONS

Two Axis Accelerometer

Three Axis Accelerometer

Gyroscope

Diffraction Grating

Optical Modulator

Microbolometer Array


Surface MEMS Design



DEVICE CROSS SECTION

Starting Wafer

Field

Oxide

Bottom Poly

Mechanical Poly Layer Metal

Bottom Poly 1 (Red) Layer 1Sacrificial Oxide (Blue Outline) Layer 2Anchor (Green) Layer 3Mechanical Poly 2 (Purple) Layer 4Contact Cut (White) Layer 6Metal (Blue) Layer 7Outline (Yellow Outline) Layer 9No Implant Yellow Layer 15Holes Layer 16 (combined with Poly 2)Release

Sacrificial Oxide


Surface MEMS Design



KEY EQUATIONS

Cantilever Deflection - YmaxF = force at end of cantileverE = Youngs Modulusb = beam widthL = beam Lengthh = beam thickness

Stress for Cantilevers = stress at anchor

Electrostatic Force - Feo = 8.85e-14 V/cmer = relative permitivittyd = distance between platesV = voltsA = area of plates

Capacitance - C

Ymax 3 E bh3

F =12L3

12 F Lsx=0 =

2b h2

2d2

o r AV2F =

d

o r AC =


Surface MEMS Design



KEY EQUATIONS

Force due to Accelerationm = massa = accelerationd = densityV = volume

Resistance - RRhos = Sheet ResistanceL = LengthW = Widthq = 1.6E-19u = mobility

m a = d V aF =

Rhos L/W

Rhos=1/(qu Dose)

R =

For single crystal silicon


Surface MEMS Design



CALCULATIONS


Surface MEMS Design



MENTOR GRAPHICS LAYOUT OF CANTILEVER


Surface MEMS Design



SWITCH CALCULATIONS PLUS DIMENSIONS

Each project has 5mm x 5mm layout space


Surface MEMS Design



SWITCH LAYOUT

Bottom Poly

Sacrificial Oxide

Anchor Cuts

Mechanical Poly

CC

Metal


Surface MEMS Design



MEMS MULTICHIP PROJECT TEMPLATE

5mm by 5mmdesign spacefor each project

Total 15 mm by 15 mm plus 500 um for sawing into 9 chips for overall 16.5mm by 16.5mm size.

Wafer sawing is easier if all chips are the same size


Surface MEMS Design



TEST STRUCTURES

One of the cells will have test structures along the bottom edge for resolution/overlay, etc.

Lithographic overlay and resolution test structure


Surface MEMS Design



TEST STRUCTURES

Test structures:

Maximum Poly2 simple cantilever width over SacOx that releases with no etch holes.

Minimum etch hole size that works. 1x1um 2x2um 3x3um 4x4umCrossover using SacOxCrossover no SacOxResistance of No_Implant Poly2 Resistor L=2WResistance of Poly2 Resistor L=2W no holesResistance of Poly2 Resistor with holes L=2WResistance of Poly1 Resistor L=2WContacts to Poly2Contacts to Poly1Contact between Poly1 and Poly2Substrate connection metal/anchor/cut to Substrate

More


Surface MEMS Design



LAYOUT RULES

Perfect Overlay Slight Overlay

Not Fatal

Misalignment

Fatal

Layout rules prevent slight misalignment from being fatal. Also, rules help make device performance consistent (minimum width for resistor will make values more consistent)


Surface MEMS Design



DESIGN RULES (GUIDELINES)

1. Outline is used to define the 5mm x 5mm work space.

2. Minimum metal pad size for probing and wirebond connections is 150 µm by 150 µm, bigger may be better except for capacitor sensor connections. Pads should be placed around the perimeter of the 5mm x 5mm workspace if possible.

3. Use Poly1 Layer for PG Text lettering.

4. If mechanical Poly2 has sacrifical oxide under it and you plan to remove the sacrifical oxide then 4um by 4um etch holes on a 10um grid (offset) need to be included. Draw the holes on separate layer. We will combine with mechanical Poly2 at maskmaking.

5. Smallest gap in Poly2 is 1 or 2um (2um gap works, 1um works sometimes)


Surface MEMS Design




6. Electrical connections to Poly1 could be Metal over Cut over Poly2 over Anchor over Poly 1. (Poly 2 must be bigger than Anchor)


Surface MEMS Design




7. Electrical connections to Poly2 could be Metal over Cut over Poly 2.


Surface MEMS Design



8. Poly2 should be anchored to Poly1 through Anchor which also electrically connects Poly2 to Poly1. Poly 1 should extend beyond Anchor by 10um or more. Poly 2 should extend beyond anchor by 10um.


9. Electrical contacts to Poly2 could be metal over Cut over Anchor to Poly1 which is indirectly connected to Poly2 through another anchor. Although this way to connect has more resistance it is okay for low (zero) current use. It does allow for cross overs.


Surface MEMS Design



10. Poly2 can cross over Poly1 with no electrical connection with SacOx between the two poly conductors.Should also work with no SacOx.


12. Electrical contacts to Poly2 should be metal through Cut. Metal should extend beyond Cut by 10um or more, Poly2 should extend beyond metal by 10 um if there is no SacOx or 20um if there is Sac Ox.

11. Minimum Poly2 that is not released is 2um. Minimum Poly 2 that is released is 10um.


Surface MEMS Design




13. Best not to make electrical contacts to Poly2 where Poly2 is over SacOx and Poly2 has holes. (might be necessary for some devices)

15. Metal can not survive the release etch (until we move to gold) so metal should not extend on Poly2 where holes exist for SacOx etch Inside of a Release box.

Release box

14. Release box extends beyond Poly2 (where etch holes exist) by 10u.


Surface MEMS Design



SOME EXAMPLES OF DEVICES


Surface MEMS Design



2014 MEMS MULTICHIP PROJECT DESIGN


Surface MEMS Design



2015 MEMS MULTICHIP PROJECT DESIGN


Surface MEMS Design



MEMS 2016 LAYOUT


Surface MEMS Design



VLSI DESIGN LAB


Surface MEMS Design



USING THE VLSI LAB WORKSTATIONS AND MENTOR GRAPHICS CAD TOOLS

Usually the workstation screen will be blank, press any key to view a login window. Login or switch user and then login.

Login: username (RIT computer account) Password: ********

The screen background will change and your desktop will appear. On the top of the screen click on Applications then System Tools then Terminal. A window will appear that has a Unix prompt inside.

Type module load mentor <ENTER>

Type ic <ENTER>, it will take a few seconds, then the Pyxis Layout user interface will appear. Maximize the Pyxis Layout window.


Surface MEMS Design



PYXIS WORKSPACE

It is convenient to show the Layer Palette and Session banners on the right side of the workspace. If they are not visible go to Setup > Windows> and check Layer Palette and Session. You should also check Command Shell, Message Area and Status Line.


Surface MEMS Design



USING THE HP WORKSTATIONS AND MENTOR GRAPHICS CAD TOOLS - PROCESS AND GRID

In the session menu palette on the right hand side of the screen, under Layout, select New, using the left mouse button. (also under file on top banner) For cell name type name-device. Set the process by typing /tools/ritpub/process/mems-2014 in the process field (or browse to mems-2014). Leave the Rules field blank. Click OK

At the top left of the window check that the process is mems-2014 not Default. If not correct go to top banner click on Context>Process>Set Process

The Layer Palette should now show the layers you expect to used for your device layout.

On top banner select Setup>Preferences>Display>Rulers/Grid Set Snap to 10 and 10 as shown. (or other values as necessary)


Surface MEMS Design



USING THE HP WORKSTATIONS AND MENTOR GRAPHICS CAD TOOLS – WORKSPACE, LOCATION

The plus mark + is

(0,0) the small dots

are the 10 um grid the

large dots are the

100um grid. The

mouse curser is

shown by the

diamond and is at

(100um,100um) as

indicated by the

cursor position at the

top of the workspace.


Surface MEMS Design



USING THE HP WORKSTATIONS AND MENTOR GRAPHICS CAD TOOLS – SELECTING OBJECTS

Select easy edit, Select Shape. Draw boxes by click and drag of mouse. Unselect by pressing

F2 function key. The highlighted layer in the layer palette is selected prior to drawing.

Unselect by pressing F2. Exit drawing by pressing ESC.

Selecting multiple objects is defined in

Setup>Selection

Unclick Surrounding the select

rectangle to not select the cell outline


Surface MEMS Design



DRAWING BOXES AND OTHER SHAPES

Select easy edit, right click and select Show Scroll Bars, scroll through the various edit

commands.

DRAW BOXES by click and drag of mouse. Unselect by pressing F2 function key. The

following command will draw a 3000 µm by 3000 µm box with layer 4 color/shading. Put

the curser in the workspace and start typing. A text line window will pop up. If the

command has a typo just start typing again and use the up arrow to recall previous text.

$add_shape([[0,0],[3000,3000]],4)

The Notch command is useful to change the size of a selected box or alter rectangular

shapes into more complex shapes.

Location of lower

left corner

Location of upper

right cornerBox Color


Surface MEMS Design



DRAWING CIRCLES

DRAW CIRCLES by typing $set_location_mode(@arc) return. The following command will draw a 100µm radius circle centered at (0,0) using 300 straight line segments.$add_shape($get_circle([0,0],[100,0],300),3)

To reset to rectangles type $set_location_mode(@line) return.

MOVE, COPY, DELETE, NOTCH, etc: Selected objects will appear to have a bright outline. Selected objects can be moved (Move), copied (Copy), deleted (Del), notched (Notc). When done unselect objects, press F2.

Change an Object to another layer: Selected object(s) click on Edit on the top banner, select Change Attributes, change layer name to the name you want. When done press F2to unselect


Surface MEMS Design



USING THE HP WORKSTATIONS AND MENTOR GRAPHICS CAD TOOLS - OTHER

ZOOM IN OUT: pressing the + or - sign on right key pad will zoom in or out. Also pressing shift + F8 will zoom so that all objects are in the view area. Select View then Area and click and drag a rectangle will zoom so that the objects in the rectangle are in the view area.

MOVING VIEW CENTER: pressing the middle mouse button will center the view around the pointer.

ADDING TEXT: Add > Polygon Text click on layout where you want it located. Select the text box and Edit > Change > Attributes, change pgtext, change scale to 3.0

SCREEN PRINT: Click on MGC and select Capture Screen. Enter file name and location such as Lynn.png and Desktop. After saving you can use a flash drive and transfer the file.

EXIT: Close all tabs save changes. MGC Exit.

SESSION LOCKED: If you do not save and exit correctly your design will be locked so you do not loose changes. To recover close ic pyxis and other Mentor tools. In a terminal type cd to list directory of files. Lock files end with .lck they can be removed with commandrm *.lck If you have a hierarchical design you need to remove all .lck files from the various directories find . –r *.lck


Surface MEMS Design



EXPORT CELL DESIGN AS GDS II FILE

Export as filename.gds

Email to Dr. Fuller

[email protected]

Cell layout name

Save to your desktop


Surface MEMS Design



GDS II LAYER NUMBERS

The design layer names and colors are lost when converting to GDS II. Only the layer number is kept.

Individual Student Designs are converted to GDS-II files and emailed to course instructor.

Layer

Number

1

2

3

4

7

9

6

15

16

10


Surface MEMS Design



MEMS 2016 LAYOUT


Surface MEMS Design



MASK ORDER FORM

x

770MEMS2016.gds 27MB816.5mm x 16.5mmMEMS_Template_2016

Dr FullerRIT


Surface MEMS Design



MASK ORDER FORM DETAILS

Reticle

Number

Reticle

Name

Design

Layer #’s

Boolean Function Dark/

Clear

Comment

1 Poly1 1 None Clear

2 Anchor 3 3 Inverted Dark

3 SacOx 2 None Clear

4 Poly2 4,16 4 AND (16 Inverted) Clear

5 No Implant 15 None Clear

6 Cut 6 6 Inverted Dark

7 Metal 7 None Clear

8 Release 10 Inverted Dark

Design Layer 9 Out (outline) is not used. It is only for placement of projects on the multi-project reticle template.


Surface MEMS Design



RETICLE 1 – DESIGN LAYER 1 - POLY 1


Surface MEMS Design



RETICLE 2 - LAYER 3 (INVERTED) - ANCHOR


Surface MEMS Design



RETICLE 3 – DESIGN LAYER 2 – SAC OX


Surface MEMS Design



RETICLE 4 – LAYER 4 + LAYER 16 (INV) - POLY2 + HOLES


Surface MEMS Design



LAYER 16 - HOLES (COMBINED WITH POLY2)

INVERT HOLES (LAYER 16) THEN

AND WITH POLY2 (LAYER 4) TO

MAKE HOLES IN POLY2


Surface MEMS Design



RETICLE 5 – DESIGN LAYER 15 – NO IMPLANT


Surface MEMS Design



RETICLE 6 - LAYER 6 (INVERTED) - CUT


Surface MEMS Design



RETICLE 7 – DESIGN LAYER 7 - METAL


Surface MEMS Design



RETICLE 8 – LAYER 10 (INVERTED) - RELEASE


Surface MEMS Design



ALL LEVELS AND LAYERS


Surface MEMS Design



MASK PROCESS FLOW

GDSII CATS

Computer Aided

Transcription Software

MEBES

FileMEBES

Job

Coat

PlateExposeInspectEtch Cr

Inspect

Develop

Clean

IC Graph by Mentor

Graphics

CAD

Data Prep

Ship out

Maskmaking

This process can take weeks and cost between $1000 and

$20,000 for each mask depending on the design complexity.


Surface MEMS Design



MEBES - Manufacturing Electron Beam Exposure System


Surface MEMS Design



CLEAR FIELD RETICLE FOR ASML

Poly One Non-Chrome Side Metal Chrome Side


Surface MEMS Design



ASML 5500/200

NA = 0.48 to 0.60 variables= 0.35 to 0.85 variable

With Variable Kohler, orVariable Annular illuminationResolution = K1 l/NA

= ~ 0.35µm for NA=0.6, s =0.85

Depth of Focus = k2 l/(NA)2

= > 1.0 µm for NA = 0.6i-Line Stepper l = 365 nm

22 x 27 mm Field Size


Surface MEMS Design



STEPPER JOB

Mask Barcode:

Stepper Jobname: MCEE770-MEMSLevel 0 (combi reticle)Level Clearout (combi reticle)

Level SacOx Level Poly 1Level AnchorLevel Poly 2Level CCLevel MetalLevel No ImplantLevel Release


Surface MEMS Design



RECIPES FOR RESIST COAT AND DEVELOP

Level Level

Name

Resist Coat Recipe Develop

Recipe

Resist

Thicknes

s

0 Zero OIR-620 Coat Develop 1.0um

1 Poly 1 OIR-620 Coat Develop 1.0um

2 Sac Ox OIR-620 Coat Develop 1.0um

3 Anchor S1827 MEMS-COAT MEMS-DEV 4.5um

4 Poly 2 S1827 MEMS-COAT MEMS-DEV 4.5um

5 CC S1827 MEMS-COAT MEMS-DEV 4.5um

6 Metal 1 S1827 MEMS-COAT MEMS-DEV 4.5um

7 Release S1827 MEMS-COAT MEMS-REL 4.5um

MEMS-COAT.rcp 2500rpm, 1min Hand Dispense

Exposure for S1827, 375mj/cm2, NA=0.46, s=0.45

MEMS-DEV.rcp has 200 second develop time, no hardbake


Surface MEMS Design



SURFACE MEMS 2015 PROCESS

1. Starting wafer2. PH03 – level 0, Marks3. ET29 – Zero Etch4. ID01-Scribe Wafer ID, D1…5. ET07 – Resist Strip, Recipe FF6. CL01 – RCA clean7. OX04 – 6500Å Oxide Tube 18. CV01 – LPCVD Poly 5000Å9. IM01 – Implant P31, 2E16, 60KeV10. PH03 – level 1 Poly-111. ET08 – Poly Etch12. ET07 – Resist Strip, Recipe FF13. CL01- RCA Clean 14. CV03 – OX05 700Å Dry Oxide15. CV02- LPCVD Nitride 4000Å16. PH03 – level 2 Anchor17. ET29 – Etch Nitride18. ET07 - Resist Strip, Recipe FF19. CL01 – RCA Clean20. CV03-TEOS SacOx Dep 1.75um

21. PH03 – level 3 SacOx Define22. ET06 - wet etch SacOx Define Etch23. ET07- Resist Strip, Recipe FF24. CL01 – RCA Clean25. CV01-LPCVD Poly 2um, 140 min26. PH03 - level 4 No Implant27. IM01-P31 2E16 100KeV28. ET07 Resist Strip, Recipe FF29. OX04-Anneal Recipe 11930. DE01 Four Point Probe31. PH03 - level 5 Poly232. ET68 - STS Etch33. ET07 - Resist Strip, Recipe FF34. CV02 – LPCVD Nitride 4000Å35. PH03 – level 6 Contact Cut36. ET29 – Etch Contact Cut37. ET06 – Etch Oxide38. ET07 – Resist Strip, Recipe FF39. CL01 – RCA Clean40. ME01 – Metal Deposition - Al

41. PH03 – level 7 Metal42. ET55 – Metal Etch - wet43. ET07 – Resist Strip44. PH03 – level 8 – Final SacOx45. ET66 – Final SacOx Etch46. ET07 - Resist Strip, Recipe FF47. SEM1 – Pictures48. TE01 - Testing

9-1-15

Etch rates

LPCVD Si3N4 in 5:1 BHF 120Å/min

N+Poly in BHF 50Å/min

PECVD SiO2 in 5:1 BHF 2000Å/min


Surface MEMS Design



SURFACE MEMS 2015 PROCESS

21. PH03 – level 3 SacOx Define22. ET06 - wet etch SacOx Define Etch23. ET07- Resist Strip, Recipe FF24. CL01 – RCA Clean25. CV01-LPCVD Poly 2um, 140 min26. PH03 - level 4 No Implant27. IM01-P31 2E16 100KeV28. ET07 Resist Strip, Recipe FF29. CL01 – RCA Clean30. OX05- 500Å pad oxide31. CV02 – 2000Å nitride32. PH03 - level 5 Poly233. ET29 – Plasma Etch Nitride34. ET06 – Wet Etch pad oxide35. ET68 - STS Etch Poly236. ET07 - Resist Strip, Recipe FF37. PH03 – level 6 Contact Cut38. ET29 – Etch Nitride Contact Cut39. ET06 – Etch Oxide Contact Cut40. ET07 – Resist Strip, Recipe FF

41. 39. CL01 – RCA Clean two HF 42. ME01 – Metal Deposition - Al43. PH03 – level 7 Metal44. ET55 – Metal Etch - wet45. ET07 – Resist Strip46. PH03 – level 8 – Release47. SA01 – Saw wafers ½ Thru48. Special Soap Clean49. ET66 – Final SacOx Etch50. ET07 - Resist Strip with Acetone51. Rinse and Dry w Isopropyl Pull52. TE01 – wafer level testing53. SEM1 – Pictures54. Packaging and Testing

2-22-16

1. Starting wafer2. PH03 – level 0, Marks3. ET29 – Zero Etch4. ID01-Scribe Wafer ID, D1…5. ET07 – Resist Strip, Recipe FF6. CL01 – RCA clean7. OX04 – 6500Å Oxide Tube 18. CV01 – LPCVD Poly 5000Å9. IM01 – Implant P31, 2E16, 60KeV10. PH03 – level 1 Poly-111. ET08 – Poly Etch12. ET07 – Resist Strip, Recipe FF13. CL01- RCA Clean 14. OX05 – 700Å Dry Oxide15. CV02- LPCVD Nitride 4000Å16. PH03 – level 2 Anchor17. ET29 – Etch Nitride18. ET07 - Resist Strip, Recipe FF19. CL01 – RCA Clean20. CV03-TEOS SacOx Dep 1.75um


Surface MEMS Design



FABRICATION PROCESS

Starting Wafer with Electronics

5000Å Poly n-Type

Sac Oxide from TEOS 1.7µm

6500Å Field OxideLPCVD Nitride and Pad Ox

Wet Etch Stop for Sac Ox

Poly One Photo

Etched Poly Bottom Electrode

1.

2.

4.

3.

5.

6.


Surface MEMS Design



FABRICATION PROCESS

1.7µm Mechanical No Implant

Masking, then implant n+ PolyPhoto for SacOx Define

Wet Etch TEOS Sacrificial Oxide

Photo Anchor Holes

Plasma Etch Anchor Holes

7. 9.

8. 10.

Etch Poly STS Etcher


Surface MEMS Design



FABRICATION PROCESS

CC Photo

Etch Contact CutsPhoto Release

Etch SacOx

LPCVD Nitride Deposit Metal

Photo and Etch Metal

11. 13.

12.

14.


Surface MEMS Design



FABRICATION PROCESS

Final Cross Section


Surface MEMS Design



CANTILEVER, MIRROR OR ACCELEROMETER

Electrostatic ActuationCapacitor SensorResistor SensorAccelerometer or Mirror

R

CYmaxm

V+


Surface MEMS Design





Surface MEMS Design



THERMALLY ACTUATED SPEAKER

Starting Wafer


Surface MEMS Design



THERMALLY ACTUATED SPEAKER


Surface MEMS Design



MICROPHONE

Fixed bottom plate

with holes

Top plate diaphragmOutput

Capacitance

Sound Pressure

Starting Wafer


Surface MEMS Design



MICROPHONE


Surface MEMS Design



CHEMICAL SENSOR OR HUMIDITY SENSOR

Interdigitated fingers form electrodes

for either resistive or capacitive

sensors. For capacitive sensors the

fingers are closely spaced. The

chemically sensitive coating is

resistive and the resistance changes in

the presence of some chemical to be

sensed or the coating is not conductive

but the dielectric constant changes in

the presence of some chemical to be

sensed.DC or DR


Surface MEMS Design



CHEMICAL SENSOR OR HUMIDITY SENSOR

1µm gap490µm length82 fingers500µm Heater L460µm Heater W


Surface MEMS Design



MIRROR


Surface MEMS Design



MIRRORS


Surface MEMS Design



RESISTOR - BOLOMETER

Resistor is suspended in air.


Surface MEMS Design



THERMAL FLOW SENSORS

SacOx

Silicon Substrate

Si3N4

PolysiliconAluminum

Spring 2003

EMCR 890 Class Project

Dr. Lynn Fuller

Flow

Downstream

Temp Sensor

Heater

Upstream

Temp Sensor

gas


Surface MEMS Design



GAS FLOW SENSOR

Overall Size 5000um x 1400um

Heater 700um x 200um

Sensors 700um x 50um

gas


Surface MEMS Design



HEATERS AND TEMPERATURE SENSORS

SacOx

Oxide

PolysiliconAluminum

Resistor HeaterThermocouple SensorResistor Sensor


Surface MEMS Design



SEEBECK EFFECT

When two dissimilar conductors are connected together a voltage may be generated if the junction is at a temperature different from the temperature at the other end of the conductors (cold junction) This is the principal behind the thermocouple and is called the Seebeck effect.

DV

Material 2Material 1

Hot

Cold

Nadim Maluf, Kirt Williams, An Introduction to

Microelectromechanical Systems Engineering, 2nd Ed. 2004

DV = a1(Tcold-Thot) + a2 (Thot-Tcold)=(a1-a2)(Thot-Tcold)

Where a1 and a2 are the Seebeck coefficients for materials 1 and 2


Surface MEMS Design



HEATER AND TEMPERATURE SENSORS


Surface MEMS Design



MEMS SWITCH

Electrostatic actuation (V) pulls down contactor to make connection along the signal line.

V

Signal LineSignal Line

Signal Line Signal Line


Surface MEMS Design



SWITCH CALCULATIONS PLUS DIMENSIONS

Each project has 5mm x 5mm layout space

Artur

Nigmatulin

2011


Surface MEMS Design



AC MEMS SWITCH


Surface MEMS Design



CHEVRON ACTUATOR

1000um10° Angle

Thermal Expansion for Si is 2.33E-6/°C

Current flow causes heating and movement


Surface MEMS Design



CHEVRON ACTUATOR

1000um10° Angle


Surface MEMS Design



POLYSILICON THERMAL ACTUATORS

No current flow Current flow


Surface MEMS Design



TWO ARM THERMAL ACTUATOR

Dots on 100µm


Surface MEMS Design



MICRO GRIPPER

2000µm


Surface MEMS Design



MICRO GRIPPER


Surface MEMS Design



MEMS CLASS PROJECT FALL 2015


Surface MEMS Design



SINGLE RESISTOR SENSOR AMPLIFIER DESIGN

-V

-

+

+V

-V

R1

R4

Vout

-

+

+V

-V

+V

267

0.00004%/°C with gain of 1000 and 100C


Surface MEMS Design



SINGLE SUPPLY OSCILLATOR (MULTIVIBRATOR)

-

+Vo

C

+V

R2R1

R

VT

+VR3

Vo

t

t1

+V

0

Let R1 = 100K, R2=R3=100K

and +V = 3.3

Then VT = 2.2 when Vo = 3.3

VT = 1.1 when Vo = 0


Surface MEMS Design



UNIVERSAL PUMP & FLOW SENSOR ASSEMBLY

1” by 3” PCB 0.0125” thick with 0.005”copper

Pin strip header

Hose nipples

Plastic cover


Surface MEMS Design



CROSSECTION

Pin strip header

Hose nipples

ThermosettingGlue on Plastic cover

1” by 3” PCB 0.0125” thick with 0.005”copper

MEMS chip mounted flush with PCB surface, wire bonds from MEMS chip to copper traces

Photoresist (film) channel wallsThickness 50µm to 150µm


Surface MEMS Design



AFTER WIRE BONDS, HEADER AND NIPPLES


Surface MEMS Design



SUMMARY

This project allows students to see the entire process for design, fabrication, packaging and testing of a MEMS based Microsystem.


Surface MEMS Design



REFERENCES

1. Dr. Lynn Fuller’s webpage2. more


Surface MEMS Design



HOMEWORK – PROJECT OVERVIEW

1. Where do design rules come from? What are they for?

2. Why do all individual student designs have to use the same

layout layer number for multichip project designs.

3. What are reticles, what are they used for, and how are they

made?

4. What does clear field and dark field mask mean? What

determines if the reticle should be clear field or dark field?

5. How much does a reticle cost?


Surface MEMS Design



HOMEWORK – DESIGN AND LAYOUT

1. Design And Layout a simple cantilever as shown on the following pages.

2. Use the process /tools/ritpub/process/mems-20143. Start by drawing an5000um x

5000um outline with lower left corner at (0,0)

4. Setup>Preferences>Selection only check boxes inside the selection rectangle and Intersecting the selection rectangle.


Surface MEMS Design



HOMEWORK – DESIGN AND LAYOUT

5. Draw the simple cantilever similar to that shown in the

pictures below.

6. Calculate the force needed to bend the cantilever down by 2um

7. Calculate the electrostatic force created by 10 volts

8. Describe how the resistor sensor works

9. Describe how the capacitor sensor works

10. Print out your final layout.

11. Export the GDS-II file and email to your instructor. Name

your files with yourname_cantilever.gds if you send screen

captures name it yourname_assignment.png (or .jpg, etc.)


Surface MEMS Design





Surface MEMS Design




10

00

µm


Surface MEMS Design




surface mems design project dr. lynn fuller, adam … mems design page 1 rochester institute of...

Documents