Recoverable degradation in InAs/AlSb high-electron mobility transistors: The role of hot carriers and metastable defects in AlSb

Recent observations of electrical stress-induced recoverable degradation in InAs/AlSb high-electron mobility transistors (HEMTs) have been attributed to metastable defects in the AlSb layer generated by the injected holes. Here we present a detailed theoretical analysis of the degradation mechanism. We show that recoverable degradation does not require the presence of hot carriers in the vicinity of the defects but the degradation is enhanced when the injected holes become more energetic. The metastable degradation arises without the presence of an energy barrier. A comprehensive survey of candidate defects suggest that substitutional and interstitial oxygen are responsible for the degradation. Therefore, reducing the oxygen contamination during device fabrication is likely to significantly improve the reliability of InAs/AlSb HEMTs. © 2010 American Institute of Physics