Measuring Temperature in GaN HEMTs: An Approach Based on Raman Spectroscopy

This article describes a new technique for measuring temperatures in GaN HEMTs. The method is based on Raman spectroscopy and the use of cerium oxide particles that act like micro-Raman thermometers when scanned with a UV laser. As the article explains, phonon line shifts due to Raman scattering are used to estimate the temperature of GaN layers while surface temperatures are obtained through the cerium oxide particles. The results presented also verify that the particles, which are distributed over semiconductor and metal surfaces, do not modify the electric characteristics of the GaN devices.