Study of a Polycide (WSi2/Polysilicon) Emitter for a CMOS Compatible Self-aligned Bipolar Transistor

A WSi2/polysilicon/Si bulk system has been studied in the framework of a CMOS compatible self-aligned bipolar transistor technology. The WSi2 silicide is implanted with Arsenic and used as a dopant source for the formation of the polysilicon-bulk emitter. Arsenic and boron profiles have been studied as a single dopant and in the transistor configuration. Experimental results give dopant diffusion and segregation coefficients and are used to adjust the parameters of our process simulation program on the technological process. WSi2 polycide appears to be particularly well adapted as a dopant source for self-aligned bipolar emitter in a large temperature range (1030 C - 1130 C).