Low resistive tungsten dual polymetal gate process for high speed and high density memory devices

Abstract

We developed ultra-low resistive tungsten dual polymetal gate memory device by using Ti-based diffusion barrier and a unique tungsten chemical vapor deposition (CVD) process with B2H6-based nucleation layer. The low resistive CVD-W (LRW) polymetal gate process not only reveals good gate oxide reliability comparable to PVD-W process, but also highly improved transistor performances such as signal delay characteristics.