Reliability issues of InAlAs/InGaAs high-electron-mobility transistors

Abstract

The effects of thermally stressing submicron In/sub x/Ga/sub 1-x/As/InAlAs/InP (x>or=0.53) HEMTs for storage periods of up to 100 h at 200 degrees C are discussed. DC characteristics are found to degrade. I/sub DSS/ decreased from 299 mA/mm to 182 mA/mm. G/sub m/ decreased from 513 mS/mm to 209 mS/mm. Decreases in microwave performance were also measured. f/sub T/ and f/sub max/ decreased by more than 30% and 20%, respectively. Evidence indicates that changes in the channel/buffer interface and layers manifested by the presence of additional trapping are responsible for this. Measurements of ohmic contacts show an increase from 0.19 Omega -mm to 0.26 Omega -mm. Results of X-ray analysis and Hall characterization are presented.<>