A novel Si/SiGe heterojunction pMOSFET with reduced short-channel effects and enhanced drive current

Abstract

A novel Si/SiGe bandgap engineered pMOSFET structure, called a high mobility heterojunction transistor (HMHJT), is proposed. Reduced short-channel effects and high drive current are predicted in this new device. Simulation results of devices with 100-nm physical gate lengths are presented. Physical effects are illustrated, and the performance is compared to the conventional Si devices. For low standby power or low leakage (high V/sub T/) applications, the off-state leakage current due to drain induced barrier lowering (DIBL) or bulk punchthrough is substantially suppressed, and a very high I/sub on//I/sub off/ ratio of 6/spl times/10/sup 7/ is obtained in a HMHJT without any anti-punchthrough implant. This ratio is a factor of 180 higher than that of a fabricated, conventional Si device with a similar threshold voltage found in the literature. On the other hand, for lower operating power (low V/sub T/) applications, an HMHJT has a drive current 80% higher compared to an optimized Si device, while satisfying the same criteria for the off-state leakage current.