Mechanism of Vfb roll-off with High Work function Metal Gate and Low Temperature Oxygen Incorporation to Achieve PMOS Band Edge Work function

摘要

Vfb roll-off phenomena in high work function (WF) metal gate on high-k is successfully explained by progressive oxygen vacancy (VO⁺) generation in high-k as bottom oxide scales. Based on this understanding, low temperature O incorporation (LTOI) process has been developed, which reduces PMOS Vt significantly by enriching high-k with O without increasing equivalent oxide thickness (EOT).