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

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

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

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

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

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]

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

Dynamic RDSon: EPC 2010_06 (200 V) VCC = 80-120-160 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

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

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

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)

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

EPC 2010 #5 (3E14 p/cm2 )

EPC 2010 #5 (3E14 p/cm2 )

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

EPC 2015 #1 (1E14 p/cm2 )

EPC 2015 #1 (1E14 p/cm2 )

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

EPC 2015 #2 (2E14 p/cm2 )

EPC 2015 #2 (2E14 p/cm2 )

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

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