The effectiveness of heat extraction by the drain metal contact of β-Ga2O3 MOSFETs

Beta-phase gallium oxide (β-Ga
₂
O
₃
) has garnered considerable attention for power devices due to (i) its large critical electric field strength and (ii) the availability of low cost/high quality melt-grown substrates, both of which are advantages over silicon carbide (SiC) and gallium nitride (GaN). However, because of the low thermal conductivity of β-Ga
₂
O
₃
, thermal management strategies at the device-level are required to achieve high-power operation. In this work, electrically identical MOSFETs (fixed current channel length) with varying spacings between the gate electrode and drain metal contact (thus, thermally different) have been fabricated, to study the effectiveness of heat extraction by the drain metal electrode. Results show that the topside features of lateral β-Ga
₂
O
₃
MOSFETs are important in both electrical and thermal design perspectives.