medium voltage sic mosfet jedec reliability qualification › ~neil › sic_workshop ›...
TRANSCRIPT
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© 2018 Cree, Inc. All rights reserved© 2018 Cree, Inc. All rights reserved
Dave Grider, Edward Van Brunt , Shadi Sabri,Jim Richmond, Brett Hull, Scott Allen, and John W. PalmourWolfspeed, a Cree Company; Research Triangle Park, NC [email protected]
Medium Voltage SiC MOSFETJEDEC Reliability Qualification
13th Annual SiC MOS Workshop, UMD, Aug. 16-17, 2018
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© 2018 Cree, Inc. All rights reserved 2
Overcoming Adversity
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© 2018 Cree, Inc. All rights reserved 3
• Packaged parts tested• 3 lots / 25 parts each, no failures allowed• Typically at or near rated voltage levels, rated temperature, 1000hrs• Automotive qualification (AEC) successful for E-Series 900V MOSFET and 1200V Diode
JEDEC Qualification of Wolfspeed SiC Power Devices
• HOWEVER, lifetime prediction requires taking parts to failure• Use accelerated (field, temperature,…) conditions• Extrapolate to use conditions for lifetime prediction
HTGB HTGS ESDThermal
ShockH3TRB
Gate Mechanical StructureActive Structure,Passivation, Edge
HTRB
Stressed Device Component
JEDEC Qualification Tests
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© 2018 Cree, Inc. All rights reserved 4
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• Completed on PowerAmerica-BP1/BP2 –Fabrication & JEDEC Qualification ofNew Design 3.3kV/50mOhm SiC MOSFETs and10kV/300mOhm SiC MOSFETs on 100 mm 4HN-SiC Wafers
‒ High Temperature Reverse Bias (HTRB)
‒ High Temperature Gate Bias (HTGB)
‒ Time Dependent Dielectric Breakdown (TDDB)
‒ Thermal Shock (TS)
‒ Body Diode Operating Lifetime (BDOL)
‒ Electrostatic Discharge (ESD)
‒ High Humidity High Temperature Reverse Bias (H3TRB)
• Underway on PowerAmerica-BP3 –Fabrication & JEDEC Qualification of6.5kV/100mOhm SiC MOSFETs on 150 mm 4HN-SiC Wafers
‒ High Temperature Reverse Bias (HTRB)
‒ High Temp Gate Bias (HTGB)
‒ Time Dependent Dielectric Breakdown (TDDB)
New Design 3.3kV/50m SiC MOSFET8.1mm
8.1
mm
New Design 10kV/300m SiC MOSFET
New Design 6.5kV/100m SiC MOSFET
8.1mm
8.1
mm
Medium Voltage SiC Power MOSFET JEDEC Qualification
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© 2018 Cree, Inc. All rights reserved 5
HTRB In-Situ Monitor:3.3kV/50mOhm SiC MOSFETs
No fails post 1000 Hr HTRB testFor 3.3kV/50mOhm SiC MOSFETs (3x25 Group)– Passed JEDEC HTRB Qualification Test
No fails post 1000 Hr HTRB testFor 10kV/300mOhm SiC MOSFET (3x25 Group)– Passed JEDEC HTRB Qualification Test
HTRB at 80% of Vrated , 175°C , 3 Fab Lots x 25* Devices/LotHTRB In-Situ Monitor:10kV/300mOhm SiC MOSFETs
Lot II had 20/20 passing devicesdue to lower packaging yield
Completed HTRB JEDEC Qualification Testing of3.3kV/50mOhm SiC MOSFETs and 10kV/300mOhm SiC MOSFETs
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© 2018 Cree, Inc. All rights reserved 6
No fails post 1000 Hr HTRB testFor 3.3kV/50mOhm SiC MOSFETs (3x25 Group)– Passed JEDEC HTRB Qualification Test
No fails post 1000 Hr HTRB testFor 10kV/300mOhm SiC MOSFET (3x25 Group)– Passed JEDEC HTRB Qualification Test
Lot II had 20/20 passing devicesdue to lower packaging yield
HTRB Post Measurement:3.3kV/50mOhm SiC MOSFETs
HTRB at 80% of Vrated , 175°C , 3 Fab Lots x 25* Devices/Lot
HTRB Post Measurement:10kV/300mOhm SiC MOSFETs
Completed HTRB JEDEC Qualification Testing of3.3kV/50mOhm SiC MOSFETs and 10kV/300mOhm SiC MOSFETs
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© 2018 Cree, Inc. All rights reserved 7
HTGB In-Situ Monitor:10 kV/300 mOhm SiC MOSFETs
HTGB In-Situ Monitor:3.3 kV/50 mOhm SiC MOSFETs
HTGB at Vgs-ated = 15V , 175°C , 3 Fab Lots x 25 Devices/Lot
No HTGB Failures in 1000 hrsFor 3.3kV/50mOhm SiC MOSFETs (3x25 Group)– Passed JEDEC HTGB Qualification Test
No HTGB Failures 1000 hrsFor 10kV/300mOhm SiC MOSFET (3x25 Group)- Passed JEDEC HTGB Qualification Test
Repeated at Vgs = +19V for both voltage classes with no failures
Completed HTGB JEDEC Qualification Testing of3.3kV/50mOhm SiC MOSFETs and 10kV/300mOhm SiC MOSFETs
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TDDB Life Projection:10 kV/300 mOhm SiC MOSFETs
TDDB Life Projection:3.3 kV/50 mOhm SiC MOSFETs
1e+4
1e+5
1e+6
1e+7
1e+8
1e+9
1e+10
1e+11
1e+12
1e+13
1e+14
1e+15
15 20 25 30 35 40 45 50
Gate Voltage (V)
10%, 50%, 90%Projected Failures
10%, 50%, 90%
Projected Failures
TDDB at 175°C , 1 Fab Lot x 30 Devices/Lot
Completed TDDB Gate Dielectric Testing of3.3kV/50mOhm SiC MOSFETs and 10kV/300mOhm SiC MOSFETs
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© 2018 Cree, Inc. All rights reserved 9
No Failures per JEDEC Standards for Visual Standards of Thermal Shock Test- For 3.3kV/50mOhm SiC MOSFETs (3x25 Group)- For10kV/300mOhm SiC MOSFETs (3x25 Group)
Thermal Shock (TS) Test at -55°C/175°C , 3 Fab Lots x 25 Devices/Lot
TS Pre/Post Die Images:3.3 kV/50 mOhm SiC MOSFETs
TS Pre/Post Die Images:10 kV/300 mOhm SiC MOSFETs
Completed Thermal Shock (TS) JEDEC Qualification Testing of3.3kV/50mOhm SiC MOSFETs and 10kV/300mOhm SiC MOSFETs
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SiC MOSFET Body Diode Operating Lifetime (BDOL) Test System
• 2 systems Have Been Assembled for the BDOL Test• Forced-Air Cooling with LED Power Supplies• Each BDOL Test System Configured for Either 3.3 kV (40 A) or 10 kV (15 A) Current Rating• BDOL Test System has In-Situ, Per-Die Drain Voltage and Temperature Monitoring
Completed Body Diode Operating Lifetime BDOL Qualification TestingOf 3.3kV/50mOhm SiC MOSFETs and 10kV/300mOhm SiC MOSFETs
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© 2018 Cree, Inc. All rights reserved 11
No BDOL Failures in 1000 hrsFor 3.3kV/50mOhm SiC MOSFETs
- No BDOL Failures in 1000 hrsFor 10kV/300mOhm SiC MOSFETs- Steps in Data Due to Changes in
Room Temperature, Notably at Startupof 3.3kV BDOL System at ~ 240 hrs
BDOL In-Situ Monitor:10kV/300mOhm SiC MOSFET BD @ 15A
BDOL In-Situ Monitor:3.3kV/50mOhm SiC MOSFET BD @ 40A
Completed Body Diode Operating Lifetime (BDOL) Qualification TestingOf 3.3kV/50mOhm SiC MOSFETs and 10kV/300mOhm SiC MOSFETs
BDOL Qual at Irated , 3 Fab Lots x 25* Devices/Lot
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© 2018 Cree, Inc. All rights reserved 12
• Threshold voltage shift
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© 2018 Cree, Inc. All rights reserved 13
• Completed ESD Testing of 3.3kV/50mOhm SiC MOSFETSAnd 10kV/300mOhm A SiC MOSFETs‒ HBM rated class 3B (8kV) – highest classification
‒ CDM rated Class IV (1kV) – highest classification
• Completed H3TRB Testing of 3.3kV/50mOhm SiC MOSFETSAnd 10kV/300mOhm SiC MOSFETs‒ No In-Situ Monitor for H3TRB Test System
‒ H3TRB Complete for 3.3kV/50mOhm SiC MOSFETs
‒ 72/75 pass all specs
‒ 3 failures noted with significant damage to die in-package
‒ H3TRB Complete for 10kV/300mOhm SiC MOSFETs, 75/75 parts passing
Completed ESD and H3TRB JEDEC Qualification TestingOf 3.3kV/50mOhm SiC MOSFETs and 10kV/300mOhm SiC MOSFETs
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© 2018 Cree, Inc. All rights reserved 14
• 8.1 x 8.1 mm 6.5kV/100mOhmSiC MOSFET Developed onONR SiC HEPS Program‒Over 2x Number of Die
Fabricated on 150 mm4HN-SiC Wafer
• 6.5kV/100mOhm SiCMOSFETs on 150mm 4HN-SiCWafers - Fabrication LotsUnderway In Preparation forHTRB, HTGB, and TDDBQualification
• Automated High VoltagePackage AssemblyModifications Completed Established XHV-8 Packagefor 3.3kV, 6.5kV, & 10kV SiCMOSFETs 6.5kV/100mOhm SiC MOSFET
6.5kV/100mOhm SiC MOSFETShot Map on
150 mm 4HN-SoC Wafer
6.5kV/100mOhm SiC MOSFETShot Map on 100 mm
4HN-SoC Wafer
6.5kV/100m SiC MOSFET Fabrication Underway on150mm 4HN-SiC Wafers for HTRB, HTGB, and TDDB JEDEC Qualification
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© 2018 Cree, Inc. All rights reserved© 2018 Cree, Inc. All rights reserved
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