Semiconductor device having a buffer layer against stress
View Patent ↗A semiconductor device and a method for preparing the same that can solve crack of a semiconductor film, capacitance electrodes and the like due to stress when forming a source electrode and a drain electrode in a semiconductor device having a thin film transistor and a holding capacitance with three or more capacitance electrodes is provided. Before forming the source electrode and the drain electrode, a crystalline silicon film for relaxing the stress is formed, then a contact hole connecting to the semiconductor film of the thin film transistor is opened, and a metal film to be the source electrode and the drain electrode is formed.
1. A semiconductor device comprising:
a thin film transistor, a first capacitor and a second capacitor formed over a substrate;
wherein the first capacitor has a first capacitance electrode and a second capacitance electrode formed with a first dielectric layer therebetween,
wherein the second capacitor has the second capacitance electrode and a third capacitance electrode formed with a second dielectric layer therebetween,
wherein an insulating film is formed over the thin film transistor,
wherein a connection wiring is formed over the insulating film and is connected to an active region of the thin film transistor,
wherein a buffer layer is formed between the second dielectric and the third capacitance electrode and between the first insulating film and the connection wiring.
2. The semiconductor device according to claim 1 , wherein the buffer layer is a film to relax stress generated when forming the third capacitance electrode and the connection wiring.
3. The semiconductor device according to claim 1 , wherein the buffer layer is one of a crystalline semiconductor film and an amorphous semiconductor film.
4. The semiconductor device according to claim 1 , wherein the buffer layer has a thickness of 10 to 100 nm.
5. The semiconductor device according to claim 1 , wherein the buffer layer is not in contact with the active region of the thin film transistor.
6. The semiconductor device according to claim 1 , wherein the connection wiring is at least one of a source electrode and a drain electrode.
7. The semiconductor device according to claim 1 , wherein the semiconductor device is a liquid crystal display device which is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head-mounted display, a car navigation system, a car stereo, a personal computer and a mobile information terminal.
8. The semiconductor device according to claim 1 , wherein the semiconductor device is a light-emitting device which is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head-mounted display, a car navigation system, a car stereo, a personal computer and a mobile information terminal.
9. A semiconductor device comprising:
a thin film transistor formed over a substrate;
an insulating film formed over the thin film transistor;
a buffer layer formed over the insulating film; and
a connection wiring formed over the buffer layer,
wherein the connection wiring is directly connected to an active region of the thin film transistor through a contact hole formed in the buffer layer and the insulating film,
wherein the buffer layer comprises an amorphous silicon.
10. The semiconductor device according to claim 9 , wherein the buffer layer is a film to relax stress generated when forming the connection wiring.
11. The semiconductor device according to claim 9 , wherein the buffer layer has a thickness of 10 to 100 nm.
12. The semiconductor device according to claim 9 , wherein the buffer layer is not in contact with the active region of the thin film transistor.
13. The semiconductor device according to claim 9 , wherein the connection wiring is at least one of a source electrode and a drain electrode.
14. The semiconductor device according to claim 9 , wherein the semiconductor device is a liquid crystal display device which is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head-mounted display, a car navigation system, a car stereo, a personal computer and a mobile information terminal.
15. The semiconductor device according to claim 9 , wherein the semiconductor device is a light-emitting device which is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head-mounted display, a car navigation system, a car stereo, a personal computer and a mobile information terminal.
16. A semiconductor device comprising:
a thin film transistor formed over a substrate;
an insulating film formed over the thin film transistor;
a buffer layer formed over the insulating film; and
a connection wiring formed over the buffer layer,
wherein the connection wiring is directly connected to an active region of the thin film transistor through a contact hole formed in the buffer layer and the insulating film,
wherein the buffer layer comprises a crystalline silicon.
17. The semiconductor device according to claim 16 , wherein the buffer layer is a film to relax stress generated when forming the connection wiring.
18. The semiconductor device according to claim 16 , wherein the buffer layer has a thickness of 10 to 100 nm.
19. The semiconductor device according to claim 16 , wherein the buffer layer is not in contact with the active region of the thin film transistor.
20. The semiconductor device according to claim 16 , wherein the connection wiring is at least one of a source electrode and a drain electrode.
21. The semiconductor device according to claim 16 , wherein the semiconductor device is a liquid crystal display device which is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head-mounted display, a car navigation system, a car stereo, a personal computer and a mobile information terminal.
22. The semiconductor device according to claim 16 , wherein the semiconductor device is a light-emitting device which is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head-mounted display, a car navigation system, a car stereo, a personal computer and a mobile information terminal.
23. A semiconductor device comprising:
a first capacitance electrode formed over a substrate;
a first dielectric layer formed over the first capacitance layer;
a second capacitance electrode formed over the first dielectric layer;
a second dielectric layer formed over the second capacitance layer;
a buffer layer formed over the second dielectric layer; and
a third capacitance electrode formed over the buffer layer,
wherein the buffer layer comprises an amorphous silicon.
24. The semiconductor device according to claim 23 , wherein the buffer layer is a film to relax stress generated when forming the third capacitance electrode.
25. The semiconductor device according to claim 23 , wherein the buffer layer has a thickness of 10 to 100 nm.
26. The semiconductor device according to claim 23 , wherein the semiconductor device is a liquid crystal display device which is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head-mounted display, a car navigation system, a car stereo, a personal computer and a mobile information terminal.
27. The semiconductor device according to claim 23 , wherein the semiconductor device is a light-emitting device which is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head-mounted display, a car navigation system, a car stereo, a personal computer and a mobile information terminal.
28. A semiconductor device comprising:
a first capacitance electrode formed over a substrate;
a first dielectric layer formed over the first capacitance layer;
a second capacitance electrode formed over the first dielectric layer;
a second dielectric layer formed over the second capacitance layer;
a buffer layer formed over the second dielectric layer; and
a third capacitance electrode formed over the buffer layer,
wherein the buffer layer comprises a crystalline silicon.
29. The semiconductor device according to claim 28 , wherein the buffer layer is a film to relax stress generated when forming the third capacitance electrode.
30. The semiconductor device according to claim 28 , wherein the buffer layer has a thickness of 10 to 100 nm.
31. The semiconductor device according to claim 28 , wherein the semiconductor device is a liquid crystal display device which is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head-mounted display, a car navigation system, a car stereo, a personal computer and a mobile information terminal.
32. The semiconductor device according to claim 28 , wherein the semiconductor device is a light-emitting device which is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head-mounted display, a car navigation system, a car stereo, a personal computer and a mobile information terminal.