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

In this letter, we report on the impact of a PEALD-AlN interfacial passivation layer (IPL) and an in-situ NH
₃
post remote-plasma (PRP) treatment onto InGaAs quantum-well MOSFETs with Ti/HfO
₂
/InGaAs gate stack. Transistors with gate lengths down to 80 nm have been fabricated and characterized. Due to the excellent interfacial quality of HfO
₂
/AlN/InGaAs, the subthreshold swing and the peak effective channel mobility have been improved to 93 mV/decade and 4253 cm
²
/Vs, respectively. The drain current has also shown a 4.6-fold enhancement, to 164 mA/mm (IOFF = 100 nA/μm and VDD = 0.5V), compared with the HfO
₂
control device. The results also show that the HfO
₂
/AlN device exhibits better immunity to short-channel effects (SCEs) than the HfO
₂
control device. Furthermore, during positive bias temperature instability stress, a smaller VTH and a lower Gm were observed for the sample with an AlN IPL and NH
₃
PRP treatment, indicating that it is more reliable than the sample without any IPL or plasma treatment.