Patent ID: 8253202

Claim:
A thin film transistor substrate, comprising: a first conductive type MOS transistor including: a first semiconductor layer formed on a blocking layer and having first conductive type low-concentration doping regions adjacent to both sides of a channel region, first conductive type source/drain regions adjacent to the first conductive type low-concentration doping regions, a first gate insulating layer formed on the first semiconductor layer, a first portion of a second gate insulating layer formed on the first gate insulating layer and overlapping only with the channel region and the low-concentration doping regions of the first semiconductor layer, and a first gate electrode formed on the second gate insulating layer; and a second conductive type MOS transistor including: a second semiconductor layer formed on the blocking layer and having second conductive type source/drain regions adjacent to both sides of a channel region, the first gate insulating layer formed on the second semiconductor layer, a second portion of the second gate insulating layer formed on the first gate insulating layer and overlapping with the second conductive type source/drain regions of the second semiconductor layer, and a second gate electrode formed on the second gate insulating layer.