초록 ▼

In an active matrix type liquid crystal display device, in which functional circuits such as a shift register circuit and a buffer circuit are incorporated on the same substrate, an optimal TFT structure is provided along with the aperture ratio of a pixel matrix circuit is increased. There is a str

In an active matrix type liquid crystal display device, in which functional circuits such as a shift register circuit and a buffer circuit are incorporated on the same substrate, an optimal TFT structure is provided along with the aperture ratio of a pixel matrix circuit is increased. There is a structure in which an n-channel TFT, with a third impurity region which overlaps a gate electrode, is formed in a buffer circuit, etc., and an n-channel TFT, in which a fourth impurity region which does not overlap the gate electrode, is formed in a pixel matrix circuit. A storage capacitor formed in the pixel matrix circuit is formed by a light shielding film, a dielectric film formed on the light shielding film, and a pixel electrode. Al is especially used in the light shielding film, and the dielectric film is formed anodic oxidation process, using an Al oxide film.

대표청구항 ▼

What is claimed is: 1. A portable telephone comprising:a voice output section;a voice input section;operation switches;a display device including a driver circuit and a pixel section;wherein the driver circuit comprising:a third thin film transistor comprising:a channel forming region overlapped wit

What is claimed is: 1. A portable telephone comprising:a voice output section;a voice input section;operation switches;a display device including a driver circuit and a pixel section;wherein the driver circuit comprising:a third thin film transistor comprising:a channel forming region overlapped with a gate electrode through a gate insulating film; anda second impurity region having an n-type conductivity and a first impurity region having the n-type conductivity which forms a source region or a drain region, wherein the second impurity region is between the channel forming region and the first impurity region, and wherein the first impurity region and the second impurity region are not overlapped with the gate electrode through the gate insulating film; anda fifth thin film transistor comprising:a channel forming region and a fifth impurity region having p-type conductivity which forms a source region or a drain region; andwherein the pixel section comprises:a storage capacitor; anda fourth thin film transistor comprising:a channel forming region overlapped with a gate electrode through the gate insulating film; anda fourth impurity region having the n-type conductivity and a first impurity region having the n-type conductivity which forms a source region or a drain region, wherein the fourth impurity region is between the channel forming region and the first impurity region, and wherein the first impurity region and the fourth impurity region are not overlapped with the gate electrode through the gate insulating film,wherein a length of the second impurity region is different from a length of the fourth impurity region,wherein the storage capacitor is formed by a light shielding film over the fourth thin film transistor, a dielectric film over the light shielding film, and a pixel electrode over the dielectric film,wherein the pixel electrode is connected to the fourth thin film transistor through an opening formed in a spacer, andwherein the spacer is provided on and in contact with the light shielding film.