Semiconductor device and manufacturing method of the same

A semiconductor device comprising:

• a substrate;
• a gate electrode layer over the substrate;
• a gate insulating layer over the gate electrode layer;
• a source electrode layer over the gate insulating layer;
• a drain electrode layer over the gate insulating layer;
• a semiconductor layer comprising zinc, oxide, indium and gallium over the source electrode layer, the drain electrode layer and the gate insulating layer, wherein the semiconductor layer is in contact with part of the gate insulating layer;
• a pixel electrode layer electrically connected to one of the source electrode layer and the drain electrode layer;
• and
• an EL layer over the pixel electrode layer,
• wherein the semiconductor layer comprises a channel region, and
• wherein the gate electrode layer is electrically connected to a wiring through a contact hole provided in the gate insulating layer.

A semiconductor device comprising:

• a substrate;
• a gate electrode layer over the substrate;
• a gate insulating layer over the gate electrode layer;
• a source electrode layer over the gate insulating layer;
• a drain electrode layer over the gate insulating layer;
• a semiconductor layer comprising zinc, oxide and indium or gallium over the source electrode layer, the drain electrode layer and the gate insulating layer, wherein the semiconductor layer is in contact with part of the gate insulating layer;
• a pixel electrode layer electrically connected to one of the source electrode layer and the drain electrode layer;
• and
• an EL layer over the pixel electrode layer,
• wherein the semiconductor layer comprises a channel region, and
• wherein the gate electrode layer is electrically connected to a wiring through a contact hole provided in the gate insulating layer.