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US 7,479,657 B2Granted
Semiconductor device including active matrix circuit
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorHideomi Suzawa
Life of this patent
Estimating the term…
Abstract
There is provided a combination of doping process and use of side walls which allows the source and drain of a thin film transistor of an active matrix circuit to be doped with only one of N-type and P-type impurities and which allows the source and drain of a thin film transistor used in a peripheral circuit of the same conductivity type as that of the thin film transistor of the active matrix circuit to include both of N-type and P-type impurities. Also, a thin film transistor in an active matrix circuit has offset regions by using side walls, and another thin film transistor in a peripheral circuit has a lightly doped region by using side walls.
Claims23
An active matrix display device comprising:
- at least first and second thin film transistors connected in series and formed with a semiconductor island;
- a first insulating film formed over the first and second thin film transistors;
- a second insulating film formed over the first insulating film;
- and
- a pixel electrode formed over the second insulating film;
- wherein the first insulating film has a first contact hole extending to the semiconductor island,
- wherein the second insulating film has a second contact hole extending to the semiconductor island through the first contact hole,
- wherein a diameter of the first contact hole is larger than that of the second contact hole, and
- wherein the pixel electrode is electrically connected to the semiconductor island through the first contact hole and the second contact hole.
6 more elements
An active matrix display device comprising:
- at least first and second thin film transistors connected in series and formed with a semiconductor island;
- a first insulating film formed over the first and second thin film transistors;
- a second insulating film formed over the first insulating film;
- and
- a pixel electrode formed over the second insulating film,
- wherein the first insulating film has a first contact hole extending to the semiconductor island,
- wherein the second insulating film has a second contact hole extending to the semiconductor island through the first contact hole,
- wherein a diameter of the first contact hole is larger than that of the second contact hole,
- wherein the pixel electrode is electrically connected to the semiconductor island through the first contact hole and the second contact hole, and
- wherein the first insulating film comprises silicon oxide.
7 more elements
An active matrix display device comprising:
- at least first and second thin film transistors connected in series and formed with a semiconductor island;
- a first insulating film formed over the first and second thin film transistors;
- a second insulating film formed over the first insulating film;
- and
- a pixel electrode formed over the second insulating film,
- wherein the first insulating film has a first contact hole extending to the semiconductor island,
- wherein the second insulating film has a second contact hole extending to the semiconductor island through the first contact hole,
- wherein a diameter of the first contact hole is larger than that of the second contact hole,
- wherein the pixel electrode is electrically connected to the semiconductor island through the first contact hole and the second contact hole, and
- wherein the second insulating film comprises silicon nitride.
7 more elements
An active matrix display device comprising:
- at least first and second thin film transistors connected in series and formed with a semiconductor island;
- a first insulating film formed over the first and second thin film transistors;
- a second insulating film formed over the first insulating film;
- and
- a pixel electrode formed over the second insulating film,
- wherein the first insulating film has a first contact hole extending to the semiconductor island,
- wherein the second insulating film has a second contact hole extending to the semiconductor island through the first contact hole,
- wherein the second insulating film entirely covers an inner wall surface of the first contact hole, and
- wherein the pixel electrode is electrically connected to the semiconductor island through the first contact hole and the second contact hole.
6 more elements
An active matrix display device comprising:
- at least first and second thin film transistors connected in series and formed with a semiconductor island;
- a first insulating film formed over the first and second thin film transistors;
- a second insulating film formed over the first insulating film;
- and
- a pixel electrode formed over the second insulating film,
- wherein the first insulating film has a first contact hole extending to the semiconductor island,
- wherein the second insulating film has a second contact hole extending to the semiconductor island through the first contact hole,
- wherein the second insulating film entirely covers an inner wall surface of the first contact hole,
- wherein the pixel electrode is electrically connected to the semiconductor island through the first contact hole and the second contact hole, and
- wherein the first insulating film comprises silicon oxide.
7 more elements
An active matrix display device comprising:
- at least first and second thin film transistors connected in series and formed with a semiconductor island;
- a first insulating film formed over the first and second thin film transistors;
- a second insulating film formed over the first insulating film;
- and
- a pixel electrode formed over the second insulating film,
- wherein the first insulating film has a first contact hole extending to the semiconductor island,
- wherein the second insulating film has a second contact hole extending to the semiconductor island through the first contact hole,
- wherein the second insulating film entirely covers an inner wall surface of the first contact hole,
- wherein the pixel electrode is electrically connected to the semiconductor island through the first contact hole and the second contact hole, and
- wherein the second insulating film comprises silicon nitride.
7 more elements
An active matrix display device including a plurality of pixels, each of the plurality of pixels comprising:
- a semiconductor island formed over a substrate, the semiconductor island including at least a first channel region, a second channel region, a first impurity region between the first channel region and the second channel region, a second impurity region electrically connected to a source signal line wherein the first channel region is between the first impurity region and the second impurity region, a third impurity region wherein the second channel region is between the first impurity region and the third impurity region, and a capacitor forming region adjacent to the third impurity region;
- a first gate electrode formed over the first channel region;
- a second gate electrode formed over the second channel region wherein the first gate electrode and the second gate electrode are electrically connected to a same gate signal line;
- a capacitor forming electrode formed over the capacitor forming region with a first insulating film interposed therebetween wherein the capacitor forming electrode is formed by patterning a same layer as the first gate electrode and the second gate electrode;
- a second insulating film formed over the first gate electrode, the second gate electrode and the capacitor forming electrode;
- a conductive layer formed over the second insulating film and electrically connected to the third impurity region through a contact hole of the second insulating film wherein the conductive layer extends over the capacitor forming electrode;
- a first auxiliary capacitor formed between the capacitor forming region and the capacitor forming electrode;
- and
- a second auxiliary capacitor formed between the capacitor forming electrode and the conductive layer,
- wherein the first auxiliary capacitor and the second auxiliary capacitor are electrically connected to the third impurity region in parallel.
7 more elements
Dependencies are inferred from the claim text.