Self-aligned InGaP/InGaAs/GaAs heterostructure MESFET technology for analog-digital hybrid type ICs

Abstract

This paper describes a new pseudomorphic InGaP/InGaAs/GaAs heterostructure MESFET (HMESFET) technology combined with a refractory self-aligned gate process for ultra-high-speed analog-digital hybrid type ICs. InGaAs is used as the thin channel layer for its higher carrier concentration. An undoped InGaP thin layer is used to improve breakdown voltage. A planar device process has been successfully developed by using self-aligned n/sup +/-implantation technology with refractory gate metal and oxygen ion implantation for device isolation. Symmetric and asymmetric FETs can be produced with the same technology by only changing the implantation angle.