Liquid crystal display device and manufacturing method thereof

A liquid crystal display device comprising:na TFT substrate having pixels, each pixel having a pixel electrode and a TFT formed thereon;a counter substrate; andliquid crystals put between the TFT substrate and the counter substrate;wherein the TFT includesna semiconductor layer;a first n+-a-Si layer formed on the semiconductor layer;a second n+-a-Si layer formed on the first n+-a-Si layer; anda drain electrode and a source electrode formed over the second n+-a-Si layer,wherein the semiconductor layer has a first lower surface which faces the TFT substrate, a first upper surface opposite to the first lower surface, and a first side portion between the first lower surface and the first upper surface,the first n+-a-Si layer has a second lower surface which is physical contact with the first upper surface, a second upper surface opposite to the second lower surface, and a second side portion between the second lower surface and the second upper surface,the first side portion of the semiconductor layer is not in physical contact with the first n+-a-Si layer, andthe second n+-a-Si is in physical contact with the second upper surface of the first n+-a-Si layer, the first side portion of the semiconductor layer, and the second side portion of the first n+-a-Si layer.