Electrical Characterization of Polysilicon/Monosilicon Interfaces

The effective recombination velocity (ERV) associated with the polysilicon/monosilicon interface has been measured for different polysilicon structures. Using a new measurement method, the analysis indicates that the behavior of a polysilicon/monosilicon interface, free from any intentional oxide layer and with a polysilicon layer heavily doped, is similar to the one of a single-crystal high-low junction. It is demonstrated that blocking properties of a polysilicon contact improve if an undoped polysilicon layer is interposed between the doped polysilicon and the monosilicon when a significant arsenic concentration is present at the polysilicon/monosilicon interface.