ABSTRACTIn this paper, we report electrical characterization of raised source/drain MOS transistors fabricated using selectively deposited, in-situ boron doped SixGe1-x as a solid diffusion source to form the source/drain junctions. The alloy can be deposited with an enhanced selectivity at temperatures as low as 600°C resulting in an abrupt doping profile at the SixGe1-x/Si interface. After deposition, junctions are formed by diffusion of boron from the deposited layer into the silicon substrate. The selectively deposited alloy can serve as a sacrificial layer for self-aligned silicide formation elimintaing the problem of silicon consumption in the substrate. In this work, selective depositions were performed in a typical cold-walled, lamp heated rapid thermal chemical vapor deposition (RTCVD) system at ∼ 610 °C using SiH2C12, GeH4 and B2H6 as the reactive gases. Using this process, MOS transistors with effective channel lengths down to 0.45 gtm were successfully fabricated.
