We investigated the Layer-by-Layer method to obtain thin μc-Si films. Good quality μc-Si films can be obtained at a thickness of 600 Å Ion-doping of phosphor to i-type μc-Si was investigated to realize the top-gate, self-aligned μc-Si TFT. High conductivity, more than 1 ohm-cm, can be obtained. Using the combination of Layer-by-Layer deposition method and ion-doping method, we fabricated top gate self-aligned μc-Si TFTs. The mobility of TFTs with 600Å-thick μc-Si channel layer is 1.5 cm2/Vs, which is about three times that of a-Si TFT's mobility. The top gate self-aligned μc-Si TFT is very promising technology for large LCD with high mobility.