InGaAs QW-MOSFET Performance Improvement Using a PEALD-AlN Passivation Layer and an <italic>In-Situ</italic> NH3Post 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/AlN/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 164 mA/mm ( ${I}_{ \mathrm{\scriptscriptstyle OFF}} \,\,{=}\,\,{100}$ nA/ $\mu \text{m}$ and ${V} _{\mathrm {DD}} \,\,{=}\,\,{0.5}$ V), compared with the HfO2 control device. The results also show that the HfO2/AlN device exhibits better immunity to short-channel effects (SCEs) than the HfO2 control device. Furthermore, during positive bias temperature instability stress, a smaller ${V}_{\mathrm {TH}}$ and a lower ${G}_{\mathrm {m}}$ were observed for the sample with an AlN IPL and NH3 PRP treatment, indicating that it is more reliable than the sample without any IPL or plasma treatment.