Simulation Research on Single Event Burnout Performances of p-GaN Gate HEMTs With 2DEG AlxGa1-xN Channel

In this article, the single event burnout (SEB) performances for 2DEG Al
_x

$\text{Ga}_{{1}-{x}}\text{N}$
channel p-GaN gate high electron mobility transistors (HEMTs) have been investigated comprehensively to reveal the failure mechanisms and broaden applications in harsh environments. As Al composition
${x}$
increases from 0.0 to 0.4,
${V}_{\text {BR}}$
increases from 500 to 730 V, and the corresponding SEB voltage
${V}_{\text {SEB}}$
at linear energy transfer (LET) = 10 pC/
$\mu \text{m}$
increases from 300 to 450 V. Possible mechanisms of Al
_x
$\text{Ga}_{{1}-{x}}\text{N}$
channel HEMTs from the perspective of electric field (
${E}$
-field) are proposed.
${E}$
-field near source and drain side after radiation would have a high peak
${E}$
-field and that of p-GaN layer exceeds 3.3 MV/cm of critical
${E}$
-field for GaN material, causing SEB to occur (LET = 10 pC/
$\mu \text{m}$
). When SEB occurs in HEMTs,
${E}$
-field would increase rapidly and cannot be recovered. A new phenomenon has been first discovered when SEB occurs in Al
_x
$\text{Ga}_{{1}-{x}}\text{N}$
channel HEMTs with p-GaN gate (
${x} = {0.0}$
–0.4, step = 0.1). In addition to the back-channel effect, an excess of holes would be left in the buffer layer after electrons flow toward the drain. It allows the injection of an excess of holes in the buffer layer into the gate with low potential, resulting in a sharp increase in
${I}_{\text {G}}$
. Simulation results indicate that AlGaN channel HEMTs have great advantages in SEB performances compared with the traditional GaN channel HEMTs.