Temperature measurement in AlGaN/GaN High-Electron-Mobility Transistors using micro-Raman scattering spectroscopy

¹ Thales Research and Technology, Domaine de Corbeville, 91404 Orsay Cedex, France
² CRHEA-CNRS, rue Bernard Gregory, 06560 Valbonne, France

Corresponding author: raphael.aubry@thalesgroup.com

Received: 19 June 2003
Revised: 28 July 2004
Accepted: 21 December 2004
Published online: 11 March 2005

Abstract

High power RF device performance decreases as operation temperature increases (e.g. decreasing electron mobility affects cut-off frequencies and degrades device reliability). Therefore determination of device temperature is a key issue for device topology optimisation. In this work the temperature variation of AlGaN/GaN high-electron-mobility transistors grown either on silicon or sapphire substrate under bias operation was measured by micro Raman scattering spectroscopy. Temperature measurements up to power dissipation of 16 W for 4 mm development devices were carried out and a peak temperature of 650 K was determined. The difference of thermal resistance for similar devices grown on the two different substrates was assessed. The thermal resistances of different device topologies were compared to optimise the component design.