IG- and VGS-Dependent Dynamic RON Characterization of Commercial High-Voltage p-GaN Gate Power HEMTs

The dynamic on-resistance (
r
_ON
) of two mainstream 600 V/650 V
p
-GaN gate power high-electron-mobility transistors (HEMTs) with Ohmic- and Schottky-type
p
-GaN gate contacts are characterized under the hard-switching condition and show strong dependences on the gate driving conditions under both double-pulse and multipulse testing modes. The statistical measurement of multiple samples indicates this is a representative phenomenon in these two types of commercial
p
-GaN gate power HEMTs. For Ohmic-type
p
-GaN gate HEMT, gate injection current (
I
_G
) at the
on
state from the
p
-GaN gate facilitates a faster detrapping process and contributes to a smaller dynamic
r
_ON
. For Schottky-type
p
-GaN gate HEMT, the dynamic
r
_ON
shows a strong dependence on the gate overdrive voltage (
V
_GS
) because the higher
V
_GS
can compensate the increase in dynamic
r
_ON
induced by the positively shifted
V
_TH
under high drain bias. A larger
I
_G
(from 1.2 to 22 mA) and higher
V
_GS
(from 5 to 7 V) play the most important role in suppressing the dynamic
r
_ON
under high switching frequency and high drain bias condition (i.e., 400 kHz/400 V), where the reduction of dynamic
r
_ON
is 13.6% and 17.1% for Ohmic-type and Schottky-type
p
-GaN gate HEMTs, respectively.