Status of the Wide Bandgap Working Group – Gallium Nitride Leif Scheick Jet Propulsion Laboratory, California Institute of Technology, Pasadena, Ca Copyright 2015 California Institute of Technology. U.S. Government sponsorship acknowledged. This research was carried out in part by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration under the NASA Electronic Parts and Packaging Program (Code AE). Other data was collected from NASA flight projects.
Transcript
Status of the Wide Bandgap Working Group – Gallium Nitride
Leif ScheickJet Propulsion Laboratory, California Institute of Technology,
Pasadena, CaCopyright 2015 California Institute of Technology. U.S. Government sponsorship
acknowledged. This research was carried out in part by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National
Aeronautics and Space Administration under the NASA Electronic Parts and Packaging Program (Code AE). Other data was collected from NASA flight projects.
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
Current activities
• Working group discusses best methods for evaluating new wide band gap technologies for infusion into space– GRC, JPL, JSC, GSFC, AFRL– Monthly meeting to share data and resources for radiation
effects testing and reliability analyses• Previous efforts have been broad stroke testing
– Heavy ion testing• Gallium Nitride HEMTs (JPL)• Silicon Carbide MOSFETs (JPL)
– Reliability screening• Temperature cycling of GaN and SiC
• On going and future efforts– Continues radiation testing and analysis– Reliability test screens for new devices– Guidelines for implementation and testing
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
Previous body of knowledge on GaN
• Current silicon power solutions are at their innate limits for space applications– Silicon devices are at efficiency
limit– Best hi-rel devices are less then
~400 V drain-to-source• GaN devices are becoming
available– Reliability effects are a concern– Gate stress is limited (abs max
of Vgs +6, -5 V)• Integrated devices increase
robustness (GaNSystems)– Thermal effects and aging are
under study at GRC
Status of Radiation Effects in GaN
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
Previous body of knowledge on GaN• SEEs in GaN have been
observed • Used the NEPP guideline:
The Test Guideline for Single Event Gate Rupture (SEGR) of Power MOSFETs [JPL Publication 08-10 2/08]– No post irradiation stress tests
between – Testing at angle required
0 500 1000 1500 2000 2500Elapsed time [AU]
10-10
10-9
10-8
10-7
10-6
10-5
10-4
10-3
10-2
Cur
rent
(Id)
[A]
0
40
80
120
160
200
Dra
in-to
-sou
rce
Volta
ge (V
ds) [
V]
K7352 1569 MeV Xe EPC2012 200V/3A 0deg
0 0.4 0.8 1.2 1.6 2Gate-to-source Voltage (Vgs) [V]
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
Previous body of knowledge on GaN
0 2 4 6 8Wafer lot
0
40
80
120
160
200
240
Vsee
[V]
LDC1_EPC2
LDC2_EPC2
LDC3_EPC2
LDC4_EPC2
LDC1_EPC1
LDC2_EPC1
LDC3_EPC1
Average Vsee for Several Lotsof GaN HEMTs
EPC1 is EPC1012EPC2 is EPC2012
-6 -4 -2 0 2Vgs [V]
0
40
80
120
160
200
VSee
(Vd)
[V]
VSee vs. VgsXe @ 25 MeV/amu
EPC2012
0 20 40 60 80 100Cr [uF]
20
40
60
80
100
VSee
[V]
VSee vs. CrXe @ 25 MeV/amu
0.0x100 4.0x105 8.0x105 1.2x106 1.6x106
Fluence [p/cm2]
0.1
1
Frac
tion
Surv
ivin
g
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
Current investigations
• Gate to source interaction– Looking at shorting the gate to source– Parameterization of test circuits– Establishment of SEE operating area
• Angular Effects– Devices are lateral, and some effects have been seen
• Testing of emerging parts– GaNSystems– Fujitsu– Northup Grumman
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
GATE TO SOURCE INTERACTION
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
EPC with SMU holding VGS=0 V
• This is a typical response – SEE occurred at 60 V• SMU establish virtual ground
0 50 100 150 200 250
1E-007
1E-006
1E-005
0.0001
0.001
0.01
0
20
40
60
80k8748 EPC2012 Xe@41 MeV.cm2/mg
Gate current [A]Drain current [A]Drain voltage [V]Gate Voltage [V]
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
EPC with Gate Shorted to Source
• Gate current is high due to the sense line test• No SEE until 200 V• Irrelevant to space flight
0 100 200 300 400 500
1E-007
1E-006
1E-005
0.0001
0.001
0.01
0
40
80
120
160
200
k8766 EPC2012 Xe@41 MeV.cm2/mg Gate current [A]Drain current [A]Drain voltage [V]Gate Voltage [V]
Shorted gate to source
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
Investigation of SET on gate
• The real time evolution of an SEE shows gate and drain transients
• Gate surges positive, then follows the drain in negative current– Possible coupling to the
power supply• Parameterization of
test circuit (LRC etc) is next step -10 0 10 20 30
Elapsed Time [us]
-1
0
1
2
3
Cur
rent
[A]
SEE of EPC1012Vds=200 V, Vgs=0 V
Drain CurrentGate Current
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
TESTING OF GANSYSTEMSPARTS
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
SEE in 100 V GS61008
• Irradiation with Ag at LBL
• Leakage increase• One SEE out of eight
devices below 100 V• Confirmation at TAM• Variety of failure
modes
0 200 400 600 800
1E-011
1E-010
1E-009
1E-008
1E-007
1E-006
1E-005
0.0001
0.001
0.01
0
20
40
60
k2297 GS61008 Ag@48 MeV.cm2/mg Gate current [A]Drain current [A]Drain voltage [V]Gate Voltage [V]
0 200 400 600 800 1000
1E-012
1E-011
1E-010
1E-009
1E-008
1E-007
1E-006
1E-005
0.0001
0.001
0.01
0
20
40
60
80
100k2294 GS61008 Ag@48 MeV.cm2/mg
Gate current [A]Drain current [A]Drain voltage [V]Gate Voltage [V]
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
TID Results – GS61008
• HDR with 2 hr anneal• No change in subthreshold behavior
0 1000000 2000000 3000000Dose level [rad(Si)]
-0.3
-0.2
-0.1
0
0.1
Thre
shol
d Vo
ltage
(Vth
) [V]
Vgs=Vds=0 VVgs=10 V Vds=0 V
To be presented at the 5th NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop June 23-26, 2014, NASA GSFC, Greenbelt, MD.
Conclusion
• Gate to source interaction– Gate shorted to source fails at 180 V – Gate and source at virtual ground fail at 60 V– Parametrization of test setup next step
• Testing of GaNSystems parts– Ion increases the drain leakage– Low cross-section for SEE (less then 10-7 cm2)– TID looks good but more susceptible than EPC
• Future plans– Measurement of LRC circuit in testers– Development of an SOA– High voltage issues are becoming more visible– Continual search for GaN IGFET
Status of Reliability Effects in GaN
National Aeronautics and Space Administration
www.nasa.gov
Reliability Assessment of WideBandgap Power Devices
Kristen Boomer, NASA GRCLeif Scheick, JPL
Jean-Marie Lauenstein & Megan Casey, NASA GSFCAhmad Hammoud, Vantage Partners LLC
NEPP 6th Electronics Technology WorkshopNASA Goddard Space Flight Center
June 23 – 26, 2015
National Aeronautics and Space Administration
www.nasa.gov 18
Scope of Work
• A NEPP collaborative effort among NASA Centers to address reliability of new COTS wide bandgap power devices
Approach
• Identify, acquire, and evaluate performance of emerging GaN (Gallium Nitride) & SiC (Silicon Carbide) power devices under the exposure to radiation, thermal cycling, and power cycling
• Document results and disseminate findings
Presentation
• Radiation & thermal cycling effects on GaN power FETs
• Wear-out board for dynamic power/thermal cycling
National Aeronautics and Space Administration
www.nasa.gov
Radiation & Thermal Cycling Effects on GaN Power FETs
19
Manufacturer Part # Parameters # Samples(control/Irradiated) Radiation Cycling
EPC 2012 200V, 3A, 100mΩ 15/26
GaN SystemsGS61008P 100V, 90A,
7.4mΩ 11/10
GS66508P 650V, 30A, 52mΩ 4/0 Planned
Radiation ExposureDevice Ion Energy (MeV) LET Range (μm) Dose (rads) Facility
EPC Xe 1569 40 124.5 8719.6 TAMU
GaN Systems Ag 1569 41 121 6634 LBL
10 ºC/min
10 min
10 min
+125 ºC
-55 ºC
Thermal Cycling: 120 cycles (Ongoing) Rate: 10 ºC/min Range: -55 ºC to +125 ºC Soak time: 10 min
EPC2012Pre-cycling Post-cycling RemarksCont Irrad Cont Irrad • Control & irradiated parts remained functional after
exposure to radiation & thermal cycling• Slight reduction in threshold voltage, modest
increase in drain-source resistance & varyingincrease in leakage current with radiation
• Insignificant effects of cycling on properties• Part-to-part variation in output characteristics• No alteration in device packaging or terminations
VTH (V) 1.21 0.90 1.02 0.84
IGSSF (µA) 0.69 0.84 0.71 0.85
IGSSR (nA) 540 779 664 881
IDSS (µA) 0.17 383 0.19 440
RDS(on) Normalized 1.0 1.33 1.06 1.04
Control Irradiated Post-cyclingVDS (V)VDS (V)
0.0 0.4 0.8 1.2 1.6 2.0
I D (A
)I D
(A)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0VGS = 2.0V
1.8V
1.2V
1.4V
1.6V
VDS (V)VDS (V)0.0 0.4 0.8 1.2 1.6 2.0
I D (A
)I D
(A)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0VGS = 2.0V
1.8V
1.2V
1.4V
1.6V
VDS (V)VDS (V)0.0 0.4 0.8 1.2 1.6 2.0
I D (A
)I D
(A)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0VGS = 2.0V
1.8V
1.2V
1.4V
1.6V
National Aeronautics and Space Administration
www.nasa.gov 22
GaN Systems Enhancement Mode Power FET
GS61008PPre-cycling Post-cycling RemarksCont Irrad Cont Irrad • Control & irradiated parts remained functional after
exposure to radiation & thermal cycling• Slight reduction in threshold voltage & modest
increase in drain-source resistance with radiation; 1 device had significant increase in leakage current
• Insignificant effects of cycling on properties• Part-to-part variation in output characteristics• No alteration in device packaging or terminations
VTH (V) 1.21 0.95 0.97 1.04
IGSSF (µA) 58.8 35.9 35 68
IGSSR (nA) 1.54 1.41 1.21 1.31
IDSS (µA) 1.40 1.24 4.94 72.2
RDS(on) Normalized 1.0 1.33 1.02 0.87
Control Irradiated Post-cycling
VDS (V)VDS (V)0.0 1.0 2.0 3.0 4.0
I D (A
)I D
(A)
0.0
0.5
1.0
1.5
1.6V
1.5V
1.7V
1.8V
1.9V
VGS = 2.0V
VDS (V)VDS (V)0.0 1.0 2.0 3.0 4.0
I D (A
)I D
(A)
0.0
0.5
1.0
1.5
2.0
1.6V
1.4V
1.5V
1.7V
1.8V
1.9V
1.3V
VGS = 2V
VDS (V)VDS (V)0.0 1.0 2.0 3.0 4.0
I D (A
)I D
(A)
0.0
0.5
1.0
1.5
1.6V
1.5V
1.7V
1.8V
1.9V
VGS = 2.0V
National Aeronautics and Space Administration
www.nasa.gov 23
GaN Systems Enhancement Mode Power FET
GS66508PPre-cycling Post-cycling Remarks
Control Control • Parts remained functional after exposure to thermal cycling with no significant changes in properties
• Part-to-part variation in output characteristics• No alteration in device packaging or terminations
VTH (V) 1.59 1.41
IGSSF (µA) 471.5 465.7
IGSSR (nA) 0.41 0.33
IDSS (µA) 6.37 5.53
RDS(on) Normalized 1.0 1.08
Pre-cycling Post-cycling
VDS (V)VDS (V)0.0 1.0 2.0 3.0 4.0
I D (A
)I D
(A)
0.0
0.5
1.0
1.5
2.0
2.1V
2.3V
2.2V
2.0V
1.9V
2.4V
VGS = 2.5V
1.8V
VDS (V)VDS (V)0.0 1.0 2.0 3.0 4.0
I D (A
)I D
(A)
0.0
0.5
1.0
1.5
2.0
2.1V
2.3V
2.2V
2.0V
1.9V
2.4V
VGS = 2.5V
1.8V
National Aeronautics and Space Administration
www.nasa.gov 24
Wear-out board for dynamic power/thermal cycling
National Aeronautics and Space Administration
www.nasa.gov
Planned Work
Continue multi-stress tests on control and irradiated GaN & SiC power devices
Power Cycling Static (Gate DC voltage) Dynamic (Gate AC voltage)
ACKNOWLEDGMENT
This collaborative work was performed in support of the NASA Electronic Parts and Packaging Program. Guidance and funding provided by the Program’s co-managers Michael Sampson and Kenneth LaBel are greatly appreciated. Part of this work was done at the NASA Glenn Research Center under GESS-3 Contract # NNC12BA01B.
