Understanding and Mitigating Stress Memorization Technique of Induced Layout Dependencies for NMOS HKMG Device

Abstract

For the first time, this research addresses the notable layout proximity effects induced by stress memorization technique in planer high-k/Metal gate NMOS device systematically, including width effect, different shallow trench spacing effect, and length of diffusion effect. Based on the oxygen diffusion mechanism analysis of layout proximity effects in high-k/Metal gate NMOS device, an optimized process is proposed to suppress the layout dependency. The experiment result indicates that modified low temperature stress memorization technique process can suppress layout dependency efficiently without performance degradation of the devices.

Keywords

• Layout proximity effects
• high-k HfO₂
• stress memorization technique
• Al diffusion