Semiconductor device equipped with semiconductor circuits composed of semiconductor elements and process for production thereof

• US 6,144,082 A
• Filed: 07/14/1999
• Issued: 11/07/2000
• Est. Priority Date: 07/16/1998
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Isobe, Atsuo, Takayama, Toru, Fukuchi, Kunihiko, Yamazaki, Shunpei, Fujimoto, Etsuko
• Primary Examiner(s): Hardy, David
• Assistant Examiner(s): Ortiz, Edgardo
• Application Number:
  US09/353,282
• Time in Patent Office: 482 Days
• Field of Search: 257/310, 257/382, 257/383, 257/411, 257/412, 257/413, 257/761
• US Class Current: 257/412
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 27/1277 using a crystallisation promoting species, e.g. local introduction of Ni catalyst
• CPC Class Codes: H01L 29/42384 for thin film field effect transistors, e.g. characterised by the thickness or the shape of the insulator or the dimensions, the shape or the lay-out of the conductor
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT

Abstract

A semiconductor device and a process for production thereof, said semiconductor device having a new electrode structure which has a low resistivity and withstands heat treatment at 400° C. and above. Heat treatment at a high temperature (400-700° C.) is possible because the wiring is made of Ta film or Ta-based film having high heat resistance. This heat treatment permits the gettering of metal element in crystalline silicon film. Since this heat treatment is lower than the temperature which the gate wiring (0.1-5 μm wide) withstands and the gate wiring is protected with a protective film, the gate wiring retains its low resistance.

Claims

1. A semiconductor device equipped with semiconductor circuits composed of semiconductor elements, said semiconductor elements comprising:

a substrate having an insulating surface;

a gate electrode of multi-layer structure over said substrate,

a protective film covering said substrate and the top and sides of said gate electrode,

a gate insulating film covering said protective film, and

a semiconductor film over said gate insulating film, said semiconductor film having at least a pair of source and drain regions and a channel region therebetween.

2. A semiconductor device according to claim 1 wherein said gate electrode of multi-layer structure has at least one layer whose principal component is at least one kind of element selected from tantalum, molybdenum, titanium, chromium, and silicon.

3. A semiconductor device according to claim 1 wherein said gate electrode of multi-layer structure is composed of three layers arranged on top of another, with a first layer being composed mainly of tantalum and containing nitrogen, a second layer being composed mainly of tantalum, and a third layer being composed mainly of tantalum and containing nitrogen, the first layer being adjacent to the substrate.

4. A semiconductor device according to claim 1 wherein said protective film is a silicon nitride film.

5. A semiconductor device according to claim 1 wherein said protective film has a thickness of 10-100 nm.

6. A semiconductor device according to claim 1 wherein said pair of source and drain regions is at least partly silicide.

7. A semiconductor device according to claim 1 wherein said pair of source and drain region contains an impurity to impart n- or p-type conductivity.

8. A semiconductor device according to claim 1 wherein said semiconductor film contains a metal element to promote crystallization of silicon.

9. A semiconductor device according to claim 8 wherein said metal element is selected from the group consisting of Ni, Fe, Co, Pt, Cu, Au and Ge.

10. A semiconductor device according to claim 1 constitutes an electro-optical device selected from the group consisting of a liquid crystal display, an EL display and EC display.

11. A semiconductor device according to claim 10 wherein said electro-optical device is incorporated in an electronic machine selected from the group consisting of a personal computer, a video camera, a mobile computer, a goggle type display, a player for a recording medium, a digital camera, a front-type projector, and a rear-type projector.

12. A semiconductor device equipped with semiconductor circuits composed of semiconductor elements comprising;

a substrate having an insulating surface,

a gate electrode over said substrate,

a protective film covering said substrate and the top and sides of said gate electrode,

a gate insulating film covering said protective film,

a semiconductor film over said gate insulating film, said semiconductor film having at least a pair of source and drain regions and a channel region therebetween,

an inorganic insulator in contact with said channel region, and

an organic resin film in contact with at least one of said source and drain regions.

13. A semiconductor device according to claim 12 wherein said gate electrode is of three-layer structure, with a first layer being composed mainly of tantalum and containing nitrogen, a second layer being composed mainly of tantalum, and a third layer being composed mainly of tantalum and containing nitrogen.

14. A semiconductor device according to claim 12 wherein said protective film is a silicon nitride film.

15. A semiconductor device according to claim 12 wherein said protective film has a thickness of 10-100 nm.

16. A semiconductor device according to claim 12 wherein said pair of source and drain regions is at least partly silicide.

17. A semiconductor device according to claim 12 wherein said pair of source and drain region contains an impurity to impart n- or p-type conductivity.

18. A semiconductor device according to claim 12 wherein said semiconductor film contains a metal element to promote crystallization of silicon.

19. A semiconductor device according to claim 18 wherein said metal element is selected from the group consisting of Ni, Fe, Co, Pt, Cu, Au and Ge.

20. A semiconductor device according to claim 12 constitutes an electro-optical device selected from the group consisting of a liquid crystal display, an EL display and EC display.

21. A semiconductor device according to claim 20 wherein said electro-optical device is incorporated in an electronic machines selected from the group consisting of a personal computer, a video camera, a mobile computer, a goggle type display, a player for a recording medium, a digital camera, a front-type projector, and a rear-type projector.