A LPCVD polysilicon deposition with in-situ anhydrous HF cleaning process has been developed. The deposited polysilicon and interface properties have been characterized using SIMS, XTEM, RBS, and Auger analysis. The results indicate that an interface oxide free polysilicon deposition using conventional LPCVD furnace can be achieved by careful design of in-situ anhydrous HF cleaning process. After short time rapid thermal annealing, random and channel RBS studies show that most of the deposited polysilicon is epitaxially aligned with silicon substrate and there is no oxide ball up phenomenon. Twinning structure was observed under TEM. No impurity segregation at the poly-mono silicon interface confirms that the interface is oxide free. Possible applications of this polysilicon process include polysilicon emitter contact for high speed bipolar technology and source/drain contacts for MOS devices.