Semiconductor device and method of making thereof

A semiconductor device comprising:

• a channel region;
• a drain region having a p-type conductivity and containing an n-type impurity;
• and
• an impurity region disposed between said channel region and said drain region, said impurity region containing said n-type impurity at a smaller concentration than said drain region,
• wherein said impurity region contains a p-type impurity at a substantially same concentration as said drain region.

A semiconductor device comprising:

• (a) a p-channel thin film transistor formed over a substrate comprising:
• a channel region;
• a drain region having a p-type conductivity;
• and
• an impurity region disposed between said channel region and said drain region,
• (b) an n-channel thin film transistor formed over the substrate comprising:
• a channel region;
• a drain region having an n-type conductivity;
• and
• an impurity region disposed between said channel region and said drain region,
• wherein the drain regions of the p-channel thin film transistor and the n-channel thin film transistor contain an n-type impurity at a same first concentration, the impurity regions of the p-channel thin film transistor and the n-channel thin film transistor contain an n-type impurity at a same second concentration smaller than said same first concentration, and the drain region and the impurity region of the p-channel thin film transistor contain a p-type impurity at a same third concentration.

A semiconductor device comprising:

• a first semiconductor layer formed on an insulating surface;
• a second semiconductor layer formed on said insulating surface;
• a first channel region formed in said first semiconductor layer;
• a pair of first impurity regions having a first p-conductivity type in said first semiconductor layer with said first channel region interposed therebetween;
• a pair of second impurity regions having a second p-conductivity type in said first semiconductor layer wherein said second impurity regions are interposed between said first channel region and said pair of first impurity regions;
• a second channel region formed in said second semiconductor layer;
• a pair of third impurity regions having a first n-conductivity type in said second semiconductor layer with said second channel region interposed therebetween;
• and
• a pair of fourth impurity regions having a second n-conductivity type in said second semiconductor layer,
• wherein a concentration of a p-type impurity contained in said first impurity regions is substantially the same as a concentration of the p-type impurity contained in said second impurity regions, and a concentration of an n-type impurity contained in said first impurity regions is smaller than a concentration of the n-type impurity contained in said second impurity regions.

A semiconductor device comprising:

• a plurality of first thin film transistors arranged in a matrix form over a substrate;
• a driver circuit over said substrate for driving said plurality of first thin film transistors, said driver circuit comprising at least one p-channel thin film transistor, said p-channel thin film transistor comprising:
• a semiconductor layer formed over said substrate;
• a channel region formed in said semiconductor layer;
• a first impurity region having a first p-type conductivity in said semiconductor layer;
• a second impurity region having a second p-type conductivity in said semiconductor layer with said first impurity region interposed therebetween,
• wherein said first impurity region contains a p-type impurity at a substantially same concentration as said second impurity region, and said first impurity region contains an n-type impurity at a smaller concentration than said second impurity region.

A semiconductor device comprising:

• a semiconductor layer formed on an insulating surface;
• a channel region formed in said semiconductor layer;
• a first impurity region having a first p-type conductivity in said semiconductor layer;
• a second impurity region having a second p-type conductivity in said semiconductor layer with said first impurity region interposed therebetween;
• and
• an electrode in contact with said second impurity region, p1 wherein said first impurity region contains a p-type impurity at a substantially same concentration as said second impurity region, and said first impurity region contains an n-type impurity at a smaller concentration than said second impurity region.

A semiconductor device comprising:

• a semiconductor;
• a channel region formed in said semiconductor;
• source and drain regions having a p-type conductivity in said semiconductor with said channel region interposed therebetween;
• at least one impurity region in said semiconductor layer between said channel region and at least one of the source and drain regions;
• a gate electrode over the channel region with a gate insulating film interposed therebetween;
• a first interlayer insulating film formed over the channel region wherein said first interlayer insulating film has at least one contact hole;
• an electrode formed over the first interlayer insulating film and connected to one of said source and drain regions through said contact hole,
• wherein a concentration of a p-type impurity in said source and drain regions is substantially the same as a concentration of the p-type impurity in said at least one impurity region, and a concentration of an n-type impurity in said source and drain regions is larger than a concentration of the n-type impurity in said at least one impurity region.
• a second impurity region having a second p-type conductivity in said semiconductor layer with said first impurity region interposed therebetween;
• and
• an electrode in contact with said second impurity region,
• wherein said first impurity region contains a p-type impurity at a substantially same concentration as said second impurity region, and said first impurity region contains an n-type impurity at a smaller concentration than said second impurity region.