Semiconductor device and method for fabricating the same using damascene process

• US 20020000623A1
• Filed: 06/29/2001
• Published: 01/03/2002
• Est. Priority Date: 06/30/2000
• Status: Active Grant

• Current Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Original Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Inventors: Cho, Heung Jae, Park, Dea Gyu
• Granted Patent: US 6,617,212 B2
• Time in Patent Office: Days
• US Class Current: 257/388
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/28123 Lithography-related aspects, e.g. sub-lithography lengths; Isolation-related aspects, e.g. to solve problems arising at the crossing with the side of the device isolation; Planarisation aspects
• CPC Class Codes: H01L 21/31616 Deposition of Al2O3
• CPC Class Codes: H01L 29/66545 using a dummy, i.e. replacement gate in a process wherein at least a part of the final gate is self aligned to the dummy gate

Abstract

A semiconductor device and a method for fabricating the semiconductor device using a damascene process are disclosed. The method includes forming an Al₂O₃ film over a dummy gate disposed over a semiconductor substrate. Next, the dummy gate and a portion of the Al₂O₃ film are removed to form a groove defined by remains of the Al₂O₃ film and the semiconductor substrate. Then, a subsequent film is deposited within the groove, and a gate material is formed over the second film to complete the semiconductor device.

Claims

1. A method for fabricating a semiconductor device using a damascene process, comprising the steps of:

forming a dummy gate electrode on a semiconductor substrate;

forming an Al₂O₃ film over the dummy gate electrode and the semiconductor substrate;

heat-treating the semiconductor substrate;

polishing and planarizing the Al₂O₃ film to expose the dummy gate electrode;

etching the dummy gate electrode to form a groove therein;

forming an insulating film on a surface of the groove; and

forming a gate electrode on the insulating film in the groove.

2. The method of claim 1, wherein the Al₂O₃ film has a thickness of 10 to 150 Å

.

3. The method of claim 1, wherein the Al₂O₃ film is deposited by an ALD or CVD process.

4. The method of claim 1, wherein the Al₂O₃ film has a thickness of 5 to 500 Å

and is subjected to an inert gas heat treatment at a temperature of 400 to 1,000°

C.

5. The method of claim 4, wherein the inert gas heat treatment uses a gas selected from one of O₂ and N₂O.

6. The method of claim 1, wherein the Al₂O₃ film is formed by depositing an AlON film over the substrate and then thermally treating the AlON film to thereby form the Al₂O₃ film.

7. The method of claim 1, wherein the dummy gate electrode comprises a dummy gate insulating film and a dummy gate electrode silicon film.

8. A method for fabricating a semiconductor device using a damascene process, comprising the steps of.

forming a dummy gate on a semiconductor substrate, the dummy gate including a dummy gate insulating film and a dummy gate electrode;

forming an oxide film over the semiconductor substrate using an LDD oxidation process;

forming an Al₂O₃ film over the semiconductor substrate and the dummy gate;

heat-treating the semiconductor substrate;

forming source and drain regions in the semiconductor substrate;

activating the source and drain regions;

forming an interlayer insulating film over the substrate;

polishing and planarizing the interlayer insulating film and the Al₂O₃ film using a Chemical Mechanical Polishing process to expose the dummy gate electrode;

etching the dummy gate electrode and the dummy gate insulating film in sequence to form a groove defining a gate electrode region;

forming a gate insulating film on a surface of the groove; and

forming a doped polysilicon film or a gate metal film on the gate insulating film in the groove.

9. The method of claim 8, wherein the dummy gate insulating film is deposited having a thickness of 10 to 150 Å

.

10. The method of claim 8, wherein the Al₂O₃ film is formed using an ALD or CVD process.

11. The method of claim 8, wherein the Al₂O₃ film has a thickness of 5 to 500 Å

and is subjected to an inert gas heat treatment at a temperature of 400 to 1,000°

C.

12. The method of claim 8, wherein the Al₂O₃ film is formed by depositing an AlON film over the substrate and then thermally treating the AlON film to thereby form the Al₂O₃ film.

13. A method of fabricating a semiconductor device using a damascene process, comprising the steps of:

forming a dummy gate on a semiconductor substrate, the dummy gate including a dummy gate insulating film and a dummy gate electrode;

wet-etching the dummy gate;

forming an AlON film over the semiconductor substrate;

heat-treating the semiconductor substrate to transform the AlON film into an Al₂O₃ film;

heat-treating the semiconductor substrate on which the Al₂O₃ film was formed;

implanting low concentration impurity ions into the semiconductor substrate to form an LDD region in the substrate;

forming spacers on sidewalls of the dummy gate;

implanting high concentration impurity ions into the substrate to form a source/drain region;

heat-treating the substrate to activate the implanted high concentration impurity ions;

forming an interlayer insulating film on the semiconductor substrate;

polishing and planarizing the interlayer insulating film and the Al₂O₃ film using a Chemical Mechanical Polishing process to expose the dummy gate electrode;

etching the dummy gate electrode and the dummy gate insulating film in sequence to form a groove defining a gate electrode region;

forming a gate insulating film on a surface of the groove; and

forming a doped polysilicon film or a gate metal film on the gate insulating film in the groove, thereby forming a gate of the semiconductor device.

14. The method of claim 13, wherein the dummy gate insulating film is formed having a thickness of 10 to 150 Å

.

15. The method of claim 13, wherein the Al₂O₃ film is formed by an ALD or CVD) process.

16. The method of claim 13, wherein the Al₂O₃ film has a thickness of 5 to 500 Å

and is subjected to an inert gas heat treatment at a temperature of 400 to 1,000°

C.

18. The method of claim 16, wherein the film is an Al₂O₃ film.

17. A semiconductor fabrication method, comprising the steps of:

forming a film over a dummy gate structure, which is disposed over a semiconductor substrate, the film having an etch selectivity that is different than an etch selectivity of the dummy gate structure;

removing a portion of the film to expose the dummy gate structure;

selectively etching the dummy gate structure to form a groove defined by a portion of the film and the semiconductor substrate;

depositing an insulating film within the groove; and

forming a gate material over the insulating film in the groove.

19. A semiconductor device, comprising:

a substrate;

an insulating film and a gate material formed over the substrate, the insulating film having a base section narrower than an upper section thereof; and

a film formed along sides of the insulating film.

20. The semiconductor device of claim 19, wherein the film is an Al₂O₃ film.

21. A semiconductor fabrication method, comprising the steps of:

forming a dummy gate structure on a semiconductor substrate, the dummy gate structure having a base section narrower than an upper section thereof;

forming a film over the dummy gate structure;

removing a portion of the film and the dummy gate structure to form a groove defined by portions of the film and the semiconductor substrate;

depositing an insulating film within the groove; and

forming a gate material over the insulating film in the groove.

22. The method of claim 21, wherein the film is an Al₂O₃ film.

23. The method of claim 21, wherein the dummy gate electrode structure comprises a dummy gate insulating film and a dummy gate electrode silicon film.