METHOD TO ENHANCE CMOS TRANSISTOR PERFORMANCE BY INDUCING STRAIN IN THE GATE AND CHANNEL

摘要

A method of manufacturing complementary metal oxide semiconductor transistors forms different types of transistors such as N-type metal oxide semiconductor (NMOS) transistors and P-type metal oxide semiconductor (PMOS) transistors (first and second type transistors) on a substrate (12). The method forms an optional oxide layer (52) on the NMOS transistors and the PMOS transistors and then covers the NMOS transistors and the PMOS transistors with a hard material (50) such as a silicon nitride layer. Following this, the method patterns portions of the hard material layer (50), such that the hard material layer remains only over the NMOS transistors. Next, the method heats (178, 204) the NMOS transistors and then removes the remaining portions of the hard material layer (50). By creating compressive stress in the gates (22) and tensile stress (70) in the channel regions of the NMOS transistors (NFETs), without creating stress in the gates (20) or channel regions of the PMOS transistors (PFETs), the method improves performance of the NFETs without degrading performance of the PFETs.