Optical surface roughness evaluation of phosphorus-doped polysilicon films

Abstract

The surface roughness of phosphorus-doped polycrystalline silicon (polysilicon) film is widely believed to be related to its electrical property. In this work, the roughness of polysilicon films prepared in situ under varied processing conditions, is determined using an optical technique that is based on measuring the spectral absorbance of specularly reflected light. The roughness measurements attained are found to follow the logical trend of roughness anticipated from phosphorus-doped polysilicon prepared under controlled variations of temperature, pressure and phospine/silane flow ratio.