Patent ID: 9620731
Date: 2017-04-11
CPC Classifications: H01L

Claim:
1. A thin film transistor comprising: a gate electrode above a substrate; a gate insulating layer covering the gate electrode; a semiconductor layer above the gate insulating layer; and a source electrode and a drain electrode which are above the gate insulating layer, and electrically connected to the semiconductor layer, wherein the gate insulating layer is a single layer and includes a first area and a second area with a same material as the first area, the first area being above the gate electrode, the second area being different from an area above the gate electrode, the first area has a higher density than a density of the second area, the gate insulating layer has a flat surface at an area above which an area where the semiconductor layer and at least one of the source electrode and the drain electrode are contiguous is located, and the gate electrode extends below and is wider than the semiconductor layer in a width direction of the gate electrode.