1. Electrical Tests on GaN devices
Giorgio Spiazzi
University of Padova
Dept. of Information Engineering – DEI

2. Dynamic circuit test Goal:
DUT
DRIVER
VCC Rs L CF +
Io(t) iL
Goal:
Simultaneous measurement of device voltage and current during switching intervals with an inductive load

3. Dynamic circuit test VDS measurement Vpol Vmis VCC DRIVER DUT Rs L CF+
Io(t) iL
VDS measurement
Vpol
Vmis

4. EPC 2015: VDS and IDS VDC = 20V, IDS = 10A, Vgate = 5V, Ton = 412 ms
IDS [2 A/div]
VDS [21 mV/div]
VDS [21 mV/div]
Voltage measured with clamp circuit and 21:1 coaxial probe

5. Dynamic RDSon: EPC 2015 (40 V) VCC = 20 V, fsw = 5 Hz 4 devices1 2 3 4
x 10 -4 10 -3 -2 -1
DYNAMIC RDSon
[W]
Time [s]
RDSon = 4 mW
4 devices

6. EPC 2010: VDS and IDS
VDC = 160V, IDS = 16A, Vgate = 5V, Ton = 55.8 ms. Voltage measured with clamp circuit and 21:1 coaxial probe
IDS [2 A/div]
VDS [105 mV/div]
VGS [1 V/div]

7. Dynamic RDSon : EPC 1010 (200 V) VCC = 80 V, fsw = 5 Hz 4 devices1 2 3 4 5 6 7 8
x 10 -5 10 -2 -1
4 devices
[W]
RDSon = 25 mW
Time [s]

8. Dynamic RDSon: EPC 2010_06 (200 V)
VCC = V, fsw = 5 Hz
RDSon = 25 mW
4 dispositivi misurati 1 2 3 4 5 6
x 10 -5 10 -2 -1
DYNAMIC RDSon
[W]
Time [s]
120 V
160 V
80 V

9. Irradiation with 3-MeV protons at difference fluence (1-4∙1014 p/cm2)
GaN radiation test
Irradiation with 3-MeV protons at difference fluence (1-4∙1014 p/cm2)
EPC2015 (VDMAX=40V)
#1  1E14 p/cm2
#2  2E14 p/cm2
#6  3E14 p/cm2
#7  4E14 p/cm2
EPC2010 (VDMAX=200V)
#5  3E14 p/cm2
#6  1E14 p/cm2

10. EPC 2010 #6 (1E14 p/cm2 )
Floating Drain. VGS swept from 0 to -4V and back to zero. Then, from 0 to +4V and back to zero again

11. EPC 2010 #6 (1E14 p/cm2 )
Drain connected to a 0.5V voltage generator. Gate voltage swept from 0 to 3V (for any VGS value a pulsed measurement is taken so as to avoid device heating)

12. EPC 2010 #6 (1E14 p/cm2 )
VGS=3V
VGS=2V
VGS=1V

13. EPC 2010 #5 (3E14 p/cm2 )

14. EPC 2010 #5 (3E14 p/cm2 )

15. EPC 2010 #5 (3E14 p/cm2 )
VGS=3V
VGS=2V
VGS=1V

16. EPC 2015 #1 (1E14 p/cm2 )

17. EPC 2015 #1 (1E14 p/cm2 )

18. EPC 2015 #1 (1E14 p/cm2 )
VGS=3V
VGS=2V
VGS=1V

19. EPC 2015 #2 (2E14 p/cm2 )

20. EPC 2015 #2 (2E14 p/cm2 )

21. EPC 2015 #2 (2E14 p/cm2 )
VGS=3V
VGS=2V
VGS=1V

22. Irradiation results
After irradiation with 3-MeV protons at the highest fluence (4∙1014 p/cm2), the devices exhibited an increase of up to one order of magnitude in gate leakage, almost 1 V of threshold voltage reduction, degradation of the subthreshold slope, and drop in transconductance