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US 6,278,131 B1Granted
Pixel TFT and driver TFT having different gate insulation width
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsShunpei Yamazaki, Jun Koyama, Hiroshi Shibata, Takeshi Fukunaga
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Abstract
A semiconductor device having high reliability, in which TFTs with appropriate structures for the circuit functions are arranged, is provided. Gate insulating films (115) and (116) of a driver TFT are designed thinner than a gate insulating film (117) of a pixel TFT in a semiconductor device having a driver circuit and a pixel section on the same substrate. In addition, the gate insulating films (115) and (116) of the driver TFT and a dielectric (118) of a storage capacitor are formed at the same time, so that the dielectric (118) may be extremely thin, and a large capacity can be secured.
Claims42
A semiconductor device having a driver circuit section and a pixel section on the same substrate, wherein:
- a driver TFT of said driver circuit section, and a pixel TFT of said pixel section, each have a gate insulating film with a mutually differing film thickness;
- and
- a film thickness of a dielectric of a storage capacitor formed in said pixel section is the same as a film thickness of the gate insulating film of said driver TFT.
A semiconductor device having a driver circuit section and a pixel section on the same substrate, wherein:
- a film thickness of a gate insulating film of a driver TFT of said driver circuit section is thinner than the film thickness of a gate insulating film of a pixel TFT of said pixel section;
- and
- a film thickness of a dielectric of a storage capacitor formed in said pixel section is the same as the film thickness of the gate insulating film of said driver TFT.
A semiconductor device having at least one active matrix display device, said display device comprising:
- a substrate;
- a pixel electrode formed over said substrate;
- a first semiconductor island formed over said substrate, having at least one channel forming region and a region as a first capacitor forming electrode of a storage capacitor;
- a first insulating film formed on said first semiconductor island, said first insulating film including a first gate insulating film on said channel forming region and a capacitor forming insulating film on said region as the capacitor forming electrode;
- a gate electrode formed over said channel forming region with said gate insulating film interposed therebetween;
- a second capacitor forming electrode over said region as the first capacitor forming electrode with said capacitor forming insulating film interposed therebetween;
- a first thin film transistor for switching said pixel electrode, said first thin film transistor comprising said channel forming region, said gate insulating film and said gate electrode;
- a driver circuit comprising at least one second thin film transistor formed over said substrate, said second thin film transistor comprising a second semiconductor island including a channel forming region, a second gate insulating film formed on said second semiconductor island and a second gate electrode formed on said second gate insulating film,
- wherein said capacitor forming insulating film has a same thickness as said second gate insulating film and a smaller thickness than said first gate insulating film.
6 more elements
A semiconductor device having at least one active matrix display device, said display device comprising:
- a substrate;
- a pixel electrode formed over said substrate;
- a first semiconductor island formed over said substrate, having at least one channel forming region and a region as a first capacitor forming electrode of a storage capacitor;
- a first insulating film formed on said first semiconductor island, said first insulating film including a first gate insulating film on said channel forming region and a capacitor forming insulating film on said region as the capacitor forming electrode;
- a gate electrode formed over said channel forming region with said gate insulating film interposed therebetween;
- a second capacitor forming electrode over said region as the first capacitor forming electrode with said capacitor forming insulating film interposed therebetween;
- a first thin film transistor for switching said pixel electrode, said first thin film transistor comprising said channel forming region, said gate insulating film and said gate electrode;
- a driver circuit comprising at least one second thin film transistor formed over said substrate, said second thin film transistor comprising a second semiconductor island including a channel forming region, a second gate insulating film formed on said second semiconductor island and a second gate electrode formed on said second gate insulating film,
- wherein said capacitor forming insulating film has a same thickness as said second gate insulating film and a smaller thickness than said first gate insulating film, and
- wherein said second gate insulating film and said second capacitor forming insulating film are formed by thermal oxidation while said first gate insulating film is formed by thermal oxidation and a chemical vapor deposition.
7 more elements
A semiconductor device having at least one active matrix display device, said display device comprising:
- a substrate;
- a pixel electrode formed over said substrate;
- a first semiconductor island formed over said substrate, having at least one channel forming region and a region as a first capacitor forming electrode of a storage capacitor;
- a first insulating film formed on said first semiconductor island, said first insulating film including a first gate insulating film on said channel forming region and a capacitor forming insulating film on said region as the capacitor forming electrode;
- a gate electrode formed over said channel forming region with said gate insulating film interposed therebetween;
- a second capacitor forming electrode over said region as the first capacitor forming electrode with said capacitor forming insulating film interposed therebetween;
- a first thin film transistor for switching said pixel electrode, said first thin film transistor comprising said channel forming region, said gate insulating film and said gate electrode;
- a light shielding film located below at least said channel forming region of said first semiconductor island with an insulating film interposed therebetween;
- and
- a driver circuit comprising at least one second thin film transistor formed over said substrate, said second thin film transistor comprising a second semiconductor island including a channel forming region, a second gate insulating film formed on said second semiconductor island and a second gate electrode formed on said second gate insulating film,
- wherein said capacitor forming insulating film has a same thickness as said second gate insulating film and a smaller thickness than said first gate insulating film.
8 more elements
Dependencies are inferred from the claim text.