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US6436775B2
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MOSFET device fabrication method capable of allowing application of self-aligned contact process while maintaining metal gate to have uniform thickness
Assignee: Mosaid Technologies Inc
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Filing: 2001-06-20
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Granted: 2002-08-20
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Expires: 2021-06-20
Abstract
Abstract The MOSFET fabrication method allows application of a self-aligned contact (SAC) process while maintaining a metal gate, such as a tungsten gate, to have a uniform thickness. The process involves forming a metal oxide film during the formation of a metal gate structure of the MOSFET device. The metal oxide film is formed by subjecting the gate structure through a rapid thermal oxidation (RTO) treatment and then to an N 2 O plasma treatment. The treatments allow the thickness of the metal oxide to be precisely controlled. The metal oxide acts as an insulator, which prevents electrical shorts between the gate structure and a contact plug even if a misalignment of occurs during the SAC process. This is an improvement from the conventional practice of separately forming a SAC barrier film after the formation of the metal gate structure and thus saves money, time, and increases reliability and productivity. Also the performance characteristics of the device is enhanced.
Inventors
- 👤 Tae Kyun Kim
- 👤 Se Aug Jang
- 👤 In Seok Yeo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:50
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/069; H10D; H10D64/00; H10D64/01; H10D64/017; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6314; H10P14/6322; H10P52/00; H10P52/40; H10P52/403
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
178 words
A method for fabricating a MOSFET device, the method comprising: forming a sacrificial gate on an active region of a substrate; forming source and drain regions in the substrate on both sides of the sacrificial gate; forming an interlayer insulating film above the substrate including above the sacrificial gate; removing the interlayer insulating film above the sacrificial gate and removing the sacrificial gate to define a groove region; forming a gate insulating film over the substrate on the interlayer insulating film and in the groove region; depositing a metal film on the gate insulating film and filling the groove region; polishing the metal film and the gate insulating film to leave the metal film in the groove region and form a metal gate; oxidizing the metal gate to form a metal oxide film having a desired thickness on the surface of the metal gate, wherein in the step of oxidizing, the metal gate is subjected to an N 2 O plasma treatment; and conducting a rapid thermal oxidation (RTO) process prior to the N 2 O plasma treatment.
Claim 2
Independent Claim
178 words
A method for fabricating a MOSFET device, the method comprising: forming a sacrificial gate on an active region of a substrate; forming source and drain regions in the substrate on both sides of the sacrificial gate; forming an interlayer insulating film above the substrate including above the sacrificial gate; removing the interlayer insulating film above the sacrificial gate and removing the sacrificial gate to define a groove region; forming a gate insulating film over the substrate on the interlayer insulating film and in the groove region; depositing a metal film on the gate insulating film and filling the groove region; polishing the metal film and the gate insulating film to leave the metal film in the groove region and form a metal gate; oxidizing the metal gate to form a metal oxide film having a desired thickness on the surface of the metal gate, wherein in the step of oxidizing, the metal gate is subjected to an N 2 O plasma treatment; and conducting a rapid thermal oxidation (RTO) process prior to the N 2 O plasma treatment.
Claim 3
Dependent Claim
44 words
The method according to claim 1 , wherein the N 2 O plasma treatment is carried out at a temperature of about 400 to 600° C., a pressure of about 2.4 to 2.6 torr, and a plasma power of about 100 to 200 W.
Claim 4
Dependent Claim
38 words
The method according to claim 2 , wherein the N 2 O plasma treatment is carried out for a period of time capable of forming a tungsten oxide film having a thickness of about 100 to 300 Å.
Claim 5
Dependent Claim
23 words
The method according to claim 3 , wherein the N 2 O plasma treatment is carried out for about 100 to 200 seconds.
Claim 6
Dependent Claim
26 words
The method according to claim 1 , wherein the RTO treatment is carried out by ramping up to a temperature of about 500 to 700° C.
Claim 7
Dependent Claim
28 words
The method according to claim 1 , wherein the RTO treatment is carried out in an atmosphere containing a gas mixture of N 2 and O 2 .
Claim 8
Dependent Claim
20 words
The method according to claim 6 , wherein the ratio of N 2 and O 2 gas mixture is 1.0/0.15.
Claim 9
Dependent Claim
35 words
The method according to claim 1 , wherein the metal film is at least one of a tungsten (W), tungsten nitride (WN), titanium (Ti), titanium nitride (TiN), molybdenum (Mo), tantalum (Ta), and tantalum nitride (TaN).
Claim 10
Dependent Claim
17 words
The method according to claim 8 , wherein the metal film is made of tungsten (W) only.
Claim 11
Independent Claim
178 words
A method for fabricating a MOSFET device, the method comprising: forming a sacrificial gate structure on an active region of a substrate; forming source and regions in the substrate on both sides of the sacrificial gate in the active region; depositing an interlayer insulating film on the active region of the substrate and on the sacrificial gate structure; polishing the interlayer insulating film exposing the sacrificial gate structure; removing the sacrificial gate structure forming a groove such that spacers define sides of the groove and the substrate is exposed within the groove; depositing a gate insulating film in the groove such that the groove is not completely filled; forming a metal gate by depositing a metal film in a remainder of the groove; and forming a metal oxide on the metal gate, wherein the metal oxide is formed by subjecting the metal gate through a N 2 O plasma treatment, and wherein prior to subjecting the metal gate to the N 2 O plasma treatment, the metal gate is also subjected to a rapid thermal oxidation (RTO) process.
Claim 12
Independent Claim
178 words
A method for fabricating a MOSFET device, the method comprising: forming a sacrificial gate structure on an active region of a substrate; forming source and regions in the substrate on both sides of the sacrificial gate in the active region; depositing an interlayer insulating film on the active region of the substrate and on the sacrificial gate structure; polishing the interlayer insulating film exposing the sacrificial gate structure; removing the sacrificial gate structure forming a groove such that spacers define sides of the groove and the substrate is exposed within the groove; depositing a gate insulating film in the groove such that the groove is not completely filled; forming a metal gate by depositing a metal film in a remainder of the groove; and forming a metal oxide on the metal gate, wherein the metal oxide is formed by subjecting the metal gate through a N 2 O plasma treatment, and wherein prior to subjecting the metal gate to the N 2 O plasma treatment, the metal gate is also subjected to a rapid thermal oxidation (RTO) process.
Claim 13
Dependent Claim
22 words
The method according to claim 10 , wherein a thickness of the metal oxide ranges from about 100 to about 300 Å.
Claim 14
Dependent Claim
26 words
The method according to claim 10 , wherein the RTO treatment is carried out by ramping up to a temperature of about 500 to 700° C.
Claim 15
Dependent Claim
28 words
The method according to claim 10 , wherein the RTO treatment is carried out in an atmosphere containing a gas mixture of N 2 and O 2 .
Claim 16
Dependent Claim
20 words
The method according to claim 13 , wherein the ratio of N 2 and O 2 gas mixture is 1.0/0.15.
Claim 17
Dependent Claim
35 words
The method according to claim 10 , wherein the metal film is at least one of a tungsten (W), tungsten nitride (WN), titanium (Ti), titanium nitride (TiN), molybdenum (Mo), tantalum (Ta), and tantalum nitride (TaN).
Claim 18
Dependent Claim
17 words
The method according to claim 10 , wherein the metal film is made of tungsten (W) only.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-08-19 | 2006-02-18 | 2006-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-08-19 | 2010-02-18 | 2010-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-08-19 | 2014-02-18 | 2014-08-20 | $7700.00 | Window Closed / Lapsed |