Plasma Charging Damage in HK-First and HK-Last RMG NMOS Devices

This work reports on charging damage induced by gate antennae in high-κ (HK) Replacement Metal Gate (RMG) technology for the HK-first and HK-last integration flows, comparing plate and comb layouts. For the HK-first devices, a significant degradation of the Gate Induced Drain Leakage (GIDL) occurs for both types of antennae, which is analyzed in terms of activation energy and corresponding trap characteristics. The degradation of the HK-last transistors is attributed to top oxide deposition which causes a different degradation pattern. In this case, charging damage leads to a degradation of the gate leakage which correlates with the “aspect ratio” of the antenna. These differences are explained and analyzed based on the plasma characteristics.