Enhanced hot-carrier-induced degradation of 0.25-um P-MOSFETs with oxideitride composite spacer compared to those with oxide spacer

摘要

Abstract: Nitride LDD spacer material presents itself as a viable option for oxide spacer because of two important reasons; 1) possibility of reducing in the contact-poly spacing 2) possibility of achieving higher drive current. However, as the Si-Si$-3$/N$-4$/ barrier height is lower than that of Si-SiO$-2$/, hot-carrier degradation could be worse. To overcome this problem, it has been suggested that a thin layer SiO$-2$/ be deposited under the nitride spacer to improve the hot-carrier response. Tomohisa et al. showed that oxide LDD spacer and oxideitride composite spacer N- MOSFETs show better hot-carrier response than those with nitride spacer. In this paper, we show that hot-carrier degradation of P-MOSFETs with oxide/Nitride composite spacer is significantly worse than that of oxide spacer devices. !3