| 摘要 |
PURPOSE: To provide a highly reliable semiconductor device and a liquid crystal display device. CONSTITUTION: A semiconductor device 19 has a substrate 1, a semiconductor layer, a gate insulation film 7a and a gate electrode 8a. A semiconductor layer is formed on a main surface of the substrate 1 and comprises source and drain regions 3a, 3b, 4a, 4b which are adjacent to each other via a channel region 6a. A gate insulation film 7a is formed on the channel region 6a. A gate electrode 8a is formed on the gate insulation film 7a and has side walls 24a, 24b. The gate insulation film 7a comprises extension parts 39a, 39b having side walls 23a, 23b positioned in an outside of a side wall of the gate electrode 8a. One of source and drain regions comprises heavily doped impurity regions 3a, 3b formed in a region of a semiconductor layer apart from the side walls 2a, 23b of an extension part, and lightly doped impurity regions 4a, 4b that have relatively low impurity concentration compared with the heavily doped impurity region and are formed in a region of a semiconductor layer positioned below an extension part. |
