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

We discuss characteristics variance in detail, caused by probing stress in 28 nm High-K and Metal Gate process. The V_th variation of nch large size transistor increases by 20% comparing with weak probing pressure (≃ 0). Regarding small size transistors, probing stress impact both on V_th fluctuation and on T_pd 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.