Recrystallization of amorphous silicon films deposited by low-pressure chemical vapor deposition from Si2H6 gas

Abstract

This paper investigated the recrystallization of low-pressure chemical vapor deposition amorphous silicon (a-Si) films deposited using Si2H6 gas at various substrate temperatures. The grain size of recrystallized films formed from Si2H6 is larger than that formed from SiH4. The maximum grain size is obtained at the substrate temperature of 460 °C, where the nucleation rate is minimum due to the maximum structural disorder of the Si network. The structural disorder is increased not only by lowering the substrate temperature but also by increasing the deposition rate. The field effect mobility of thin-film transistors (TFTs) using the recrystallized films reaches 120 cm2 V−1 s−1, even though the highest temperature during the TFT fabrication process is only 600 °C.