InGaAs QW-MOSFET Performance Improvement Using a PEALD-AlN Passivation Layer and an In-Situ NH3 Post Remote-Plasma Treatment

Abstract

In this letter, we report on the impact of a PEALD-AlN interfacial passivation layer (IPL) and an in-situ NH3 post remote-plasma (PRP) treatment onto InGaAs quantum-well MOSFETs with Ti/HfO2/InGaAs gate stack. Transistors with gate lengths down to 80 nm have been fabricated and characterized. Due to the excellent interfacial quality of HfO2/AIN/InGaAs, the subthreshold swing and the peak effective channel mobility have been improved to 93 mV/decade and 4253 cm2/Vs, respectively. The drain current has also shown a 4.6-fold enhancement, to 164mA/mm(I-OFF = 100 nA/mu m DD = 0.5V), compared with the HfO2 control device. The results also show that the HfO2/AIN device exhibits better immunity to short-channel effects (SCEs) than the HfO2 control device. Furthermore, during positive bias temperature instability stress, a smaller V-TH and a lower Gm were observed for the sample with an AIN IPL and NH3 PRP treatment, indicating that it is more reliable than the sample without any IPL or plasma treatment.