Semiconductor device and method of manufacturing the semiconductor device

A semiconductor device comprising:

• a pixel thin film transistor in a pixel portion;
• a storage capacitor in the pixel portion;
• the pixel thin film transistor including:
• a first region of a semiconductor film having a channel forming region, a source region and a drain region;
• a gate insulating film being in contact with the first region;
• a gate electrode being formed on the gate insulating film;
• wherein the pixel thin film transistor is an n-channel thin film transistor;
• the storage capacitor including:
• a second region of the semiconductor film;
• an insulating film being in contact with the second region;
• a storage wiring being formed on the insulating film,
• wherein the gate electrode has a tapered portion,
• wherein the second region includes an impurity to impart one conductivity at a concentration in a range of 1×1020 to 1×1021 atoms/cm3,
• wherein the insulating film in contact with the second region has a thinner thickness than the gate insulating film in contact with the first region.

A semiconductor device comprising:

• a pixel portion and a driver circuit portion being formed over a substrate;
• the driver circuit including a p-channel thin film transistor and an n-channel thin film transistor;
• the n-channel thin film transistor having a semiconductor film, a gate insulating film being in contact with the semiconductor film and a gate electrode being formed on the gate insulating film;
• the semiconductor film including a channel forming region, a source region, a drain region, at least an LDD region,
• wherein the gate electrode includes a first conductive layer and a second conductive layer,
• wherein the second conductive layer is overlapped with the LDD region with the gate insulating film interposed therebetween.

A semiconductor device comprising:

• a pixel portion and a driver circuit portion being formed over a substrate;
• the pixel portion including a pixel thin film transistor and a storage capacitor;
• the pixel thin film transistor including:
• a first region of a first semiconductor film having a first channel forming region, a first source region and a first drain region;
• a first gate insulating film being in contact with the first region;
• a first gate electrode being formed on the first gate insulating film;
• wherein the pixel thin film transistor is a first n-channel thin film transistor;
• the storage capacitor including:
• a second region of the first semiconductor film;
• an insulating film being in contact with the second region;
• a storage wiring being formed on the insulating film;
• the driver circuit including a p-channel thin film transistor and a second n-channel thin film transistor;
• the second n-channel thin film transistor having a second semiconductor film, a second gate insulating film being in contact with the second semiconductor film and a second gate electrode being formed on the second gate insulating film;
• the second semiconductor film including a second channel forming region, a second source region, a second drain region, at least an LDD region;
• wherein the second gate electrode includes a first conductive layer and a second conductive layer;
• wherein the second conductive layer is overlapped with the LDD region with the second gate insulating film interposed therebetween,
• wherein the second conductive layer comprises a same material as the capacitor wiring,
• wherein the insulating film in contact with the second region has a thinner thickness than the first gate insulating film in contact with the first region.

A semiconductor device comprising:

• a pixel portion and a driver circuit portion being formed over a substrate;
• the pixel portion including a first n-channel thin film transistor and a storage capacitor;
• the storage capacitor including:
• a first semiconductor film;
• an insulating film being in contact with the first semiconductor film, said insulating film functioning as a dielectric of the storage capacitor;
• a storage wiring being formed on the insulating film;
• wherein the first semiconductor film includes an impurity to impart one conductivity at a concentration in a range of 1×1020 to 1×1021 atoms/cm3;
• the driver circuit including a p-channel thin film transistor and a second n-channel thin film transistor;
• each of the p-channel the second n-channel thin film transistors having a second semiconductor film, a gate insulating film being in contact with the second semiconductor film and a gate electrode being formed on the gate insulating film,
• wherein the gate electrode has a tapered portion;
• wherein the insulating film in a region where the storage capacitor is formed has a thinner thickness than in a region where the first n-channel thin film transistor is formed.

A semiconductor device comprising:

• a pixel portion and a driver circuit portion being formed over a substrate;
• the pixel portion including a first n-channel thin film transistor and a storage capacitor;
• the first n-channel thin film transistor including:
• a first semiconductor film having a first channel forming region, at least a first LDD region out of the first channel forming region, a first source region or a first drain region out of the first LDD region;
• a first gate insulating film being in contact with the first semiconductor film;
• a first gate electrode being formed on the first gate insulating film;
• the driver circuit including a p-channel thin film transistor and a second n-channel thin film transistor;
• the second n-channel thin film transistor including:
• a second semiconductor film having a second channel forming region, at least a second LDD region out of the second channel forming region, a second source region or a second drain region out of the second LDD region;
• a second gate insulating film being in contact with the second semiconductor film;
• a second gate electrode being formed on the second gate insulating film;
• wherein each of the first gate electrode of the first n-channel thin film transistor in the pixel portion and the second gate electrode of the second n-channel thin film transistor in the driver circuit portion has a tapered portion,
• wherein an insulating film continuously formed from the first gate insulating film functioning as a dielectric of the storage capacitor has a thinner thickness than other regions.