Deposition trend of μc-Si was investigated using microwave (2.45GH z) plasma enhanced CVD. μc-Si films with the preferential orientation of (111) and (220) were deposited and compared. Raman scattering results show that the (111) preferentially oriented film has higher crystallinity while ESR measurements result in the fact that the (220) preferentially oriented film has smaller dangling bond density. Bottom gate thin film transistors (TFT's) were fabricated using these μc-Si films as channel layer and evaluated. H2 plasma post-treatment has been found to be effective to improve the TFT characteristics. Mobility of about 1.4cm 2/Vsec and on/off ratio of more than 105 have been achieved.