PMOS Hole Mobility Enhancement Through SiGe Conductive Channel and Highly Compressive ILD- SiNₓ Stressing Layer

In this letter, the SiGe-channel PMOS transistors integrated with a highly compressive contact-etching stop-layer (CESL) interlayer-dielectric-SiNxstressing layer have been successfully fabricated. The performance improvements of devices with a gate length (Lg)of down to 40 nm were studied. For long-channel SiGe-channel PMOS, the mobility is at least 50% higher than that of the conventional bulk-Si PMOS. Moreover, compared to the conventional short-channel SiGe-channel devices, the highly compressive CESL stressor shows 32% current gain forLg= 40 nm PMOS with the thinnest 9 A Si-cap. Therefore, integrating the stressed CESL technique into the SiGe-channel structure is an efficient method for improving PMOS device performance.