Tr variance evaluation induced by probing pressure and its stress extraction methodology in 28nm High-K and Metal Gate process

Abstract

We discuss characteristics variance in detail, caused by probing stress in 28 nm High-K and Metal Gate process. The Vth variation of nch large size transistor increases by 20% comparing with weak probing pressure (≃ 0). Regarding small size transistors, probing stress impact both on Vth fluctuation and on Tpd fluctuation is small. Moreover, we extracted the space distribution of probing stress quantitatively. It is useful to calibrate a stress simulation methodology and to facilitate evaluation of the mechanical strength of the material.