Kapitza Resistance at the Two-Dimensional Electron Gas Interface

Thermal resistance at interfaces in high electron mobility transistors (such as GaN-based devices) presents a significant problem. Recent investigations report much greater thermal resistance between GaN and substrate than theory predicts. However, in devices that leverage a two-dimensional electron gas (2DEG), such as the interface between Al
_x
Ga
_(1-x)
N and GaN, little exploration has been performed regarding the effect of thermal resistance at the interface where the 2DEG is formed, and there are no experimental reports of the value of interface thermal resistance between Al
_x
Ga
_(1-x)
N and GaN. This work reports interface thermal resistance between Al
_x
Ga
_(1-x)
N and GaN to be 12.8 m
²
K/GW, and projects the effect of this resistance on temperature buildup in GaN HEMT devices.