Single-Wafer RTCVD of Polysilicon: a Complementary Step in Front-End Integrated Processing

Abstract

AbstractPolycrystalline silicon is used in the fabrication of integrated circuits in various applications. These include a MOS gate material, bipolar emitter and base contacts, trench refill, complementary material for elevated source / drain structures, solid diffusion source for formation of shallow junctions and the active material in thin film transistors. The deposition of polysilicon as the MOS gate electrode or the bipolar emitter contact follows the most critical processing steps in fabrication of these devices. Maximum reproducibility and highest device performance are achieved when the interfaces between the polysilicon and the underneath substrate are well controlled. This level of control can be obtained by combining the compatible processing steps under a controlled environment. Single-wafer RTCVD of polysilicon was introduced to complement the emerging front-end integrated processing technology for MOS, bipolar and BICMOS devices.