Impact of buffer layers on thermal properties of AlGaN/GaN-on-SiC high electron mobility transistors (HEMTs)

摘要

In this work, a combination of Raman thermography and finite element thermal modelling was used to examine the thermal conductivities of different buffer layers in four AlGaN/GaN ungated high electron mobility transistors (HEMTs). The parameterisation of the thermal conductivities of iron-doped GaN, carbon-doped GaN and Al0.04Ga0.96N buffer layers gave good agreement in thermal simulations to experimentally-measured GaN temperatures obtained by Raman thermography. This shows the viability of the combined experimental and modelling method used in this work, for the extraction of layer thermal conductivities in complex AlGaN/GaN device heterostructures.