IN-SITU TEM INVESTIGATION ON NUCLEATION AND GROWTH BEHAVIOR OF P-DOPED Si THIN FILMS

Abstract

The nucleation and growth behaviors of undoped and phosphorus doped polycrystalline Si thin films were investigated by in-situ TEM observations. Polycrystalline Si thin films were partially changed to amorphous by ion implantations. A normal grain growth was observed in the undoped Si thin films during heating. On the other hand, the P-doped sample showed the recovery and growth at grain boundary as well as the nucleation of Si nanocrystals at amorphous regions. Although the amorphous hindered the grain growth and acted as the nucleation source of Si nanocrystals at lower temperature, the final grain size of polycrystalline Si at 650 degrees C was larger in the P-doped sample. The carrier mobility of the P-doped Si thin films not only increased with heat treatments, but also was corresponding to the microstructural evolution.