US6083828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming a self-aligned contact
Assignee: United Microelectronics Corp
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Filing: 1999-03-11
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Granted: 2000-07-04
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Expires: 2019-03-11
Abstract
Abstract A method for forming a SAC opening is provided. As a self-aligned contact (SAC) opening is formed in a dielectric layer on a semiconductor substrate to expose one of source/drain regions in the substrate, a misalignment of the SAC opening may occur to expose a portion of the gate structure. The gate structure has a gate, which is covered by a cap layer on the top, a thin oxide layer on each sidewall of the gate and the cap layer, and a spacer on the thin oxide layer. The SAC opening causes a clearance between the spacer and the gate since a portion of the thin oxide layer is removed. The method contains forming an insulating layer over the substrate to fill the clearance. An etching back process is performed to remove the insulating layer so that a remaining portion of the insulating layer fills the clearance to fully isolate the gate.
Inventors
- 👤 Kwang-Ming Lin
- 👤 Russell Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:19
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/069
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
177 words
A method for forming a self-aligned contact (SAC), the method suitable for a gate structure that is formed on a semiconductor substrate and is covered by a cap layer on the top, a liner oxide layer on each sidewall of both the gate and the cap layer, and a spacer on the liner oxide layer, in which an interchangeable source/drain region is formed in the substrate at each side of the gate structure, the method comprising: forming a dielectric layer over the substrate; patterning the dielectric layer to form a SAC opening, which exposes the interchangeable source/drain region and may expose the cap layer, the liner layer, and the spacer, due to a misalignment property of the SAC opening, wherein since the liner layer is exposed, a portion of the liner layer is also removed to leave a clearance that exposes the gate structure; forming an insulating plug to fill the clearance so as to isolate the gate structure; and forming a SAC conductive plug to fill the SAC opening so as to form the SAC contact.
Claim 2
Independent Claim
177 words
A method for forming a self-aligned contact (SAC), the method suitable for a gate structure that is formed on a semiconductor substrate and is covered by a cap layer on the top, a liner oxide layer on each sidewall of both the gate and the cap layer, and a spacer on the liner oxide layer, in which an interchangeable source/drain region is formed in the substrate at each side of the gate structure, the method comprising: forming a dielectric layer over the substrate; patterning the dielectric layer to form a SAC opening, which exposes the interchangeable source/drain region and may expose the cap layer, the liner layer, and the spacer, due to a misalignment property of the SAC opening, wherein since the liner layer is exposed, a portion of the liner layer is also removed to leave a clearance that exposes the gate structure; forming an insulating plug to fill the clearance so as to isolate the gate structure; and forming a SAC conductive plug to fill the SAC opening so as to form the SAC contact.
Claim 3
Dependent Claim
69 words
The method of claim 1, wherein the step of forming the insulating plug to fill the clearance further comprises: forming an insulating layer over the substrate to at least fill the clearance; and performing an etching back process to remove the insulating layer so that a remaining portion of the insulating layer at least form the insulating plug to fill the clearance so as to isolate the gate structure.
Claim 4
Dependent Claim
20 words
The method of claim 2, wherein the step of forming the insulating layer comprises low pressure chemical vapor deposition (LPCVD).
Claim 5
Dependent Claim
20 words
The method of claim 2, wherein the step of forming the insulating layer comprises plasma enhanced chemical vapor deposition (PECVD).
Claim 6
Dependent Claim
23 words
The method of claim 2, wherein the step of performing the etching back process to remove the insulating layer comprises an anisotropic process.
Claim 7
Dependent Claim
17 words
The method of claim 2, wherein the insulating layer comprises a thickness of about 50 Å-500 Å.
Claim 8
Dependent Claim
12 words
The method of claim 1, wherein the dielectric layer comprises silicon oxide.
Claim 9
Dependent Claim
12 words
The method of claim 1, wherein the insulating plug comprises silicon nitride.
Claim 10
Dependent Claim
12 words
The method of claim 1, wherein the insulating plug comprises silicon oxynitride.
Claim 11
Dependent Claim
15 words
The method of claim 1, wherein the spacer and the cap layer comprise silicon nitride.
Claim 12
Dependent Claim
30 words
The method of claim 1, wherein a formation of the gate structure comprises sequentially forming a gate oxide layer, a polysilicon layer, and a metal silicide layer on the substrate.
Claim 13
Independent Claim
171 words
A method of protecting a gate structure, which is formed on a semiconductor substrate and is covered by a cap layer on the top, a liner oxide layer on each sidewall of both the gate and the cap layer, and a spacer on the liner oxide layer, in which an interchangeable source/drain region is formed in the substrate at each side of the gate structure, wherein a dielectric layer is formed over the substrate with a contact opening to expose the interchangeable source/drain region and the gate structure at a clearance between the spacer and the gate structure, which clearance is originally occupied by a portion of the liner oxide layer but is removed during a formation of the contact opening, the method comprising: forming an insulating layer over the substrate to fill the clearance; and performing an etching back process to remove the insulating layer so that a remaining portion of the insulating layer form an insulating plug to fill the clearance so as to fully isolate the gate structure.
Claim 14
Independent Claim
171 words
A method of protecting a gate structure, which is formed on a semiconductor substrate and is covered by a cap layer on the top, a liner oxide layer on each sidewall of both the gate and the cap layer, and a spacer on the liner oxide layer, in which an interchangeable source/drain region is formed in the substrate at each side of the gate structure, wherein a dielectric layer is formed over the substrate with a contact opening to expose the interchangeable source/drain region and the gate structure at a clearance between the spacer and the gate structure, which clearance is originally occupied by a portion of the liner oxide layer but is removed during a formation of the contact opening, the method comprising: forming an insulating layer over the substrate to fill the clearance; and performing an etching back process to remove the insulating layer so that a remaining portion of the insulating layer form an insulating plug to fill the clearance so as to fully isolate the gate structure.
Claim 15
Dependent Claim
20 words
The method of claim 12, wherein the step of forming the insulating layer comprises low pressure chemical vapor deposition (LPCVD).
Claim 16
Dependent Claim
20 words
The method of claim 12, wherein the step of forming the insulating layer comprises plasma enhanced chemical vapor deposition (PECVD).
Claim 17
Dependent Claim
23 words
The method of claim 12, wherein the step of performing the etching back process to remove the insulating layer comprises an anisotropic process.
Claim 18
Dependent Claim
17 words
The method of claim 12, wherein the insulating layer comprises a thickness of about 50 Å-500 Å.
Claim 19
Dependent Claim
12 words
The method of claim 12, wherein the insulating layer comprises silicon nitride.
Claim 20
Dependent Claim
12 words
The method of claim 12, wherein the insulating layer comprises silicon oxynitride.
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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) | 2003-07-04 | 2004-01-03 | 2004-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-07-04 | 2008-01-03 | 2008-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-07-04 | 2012-01-03 | 2012-07-04 | $7700.00 | Window Closed / Lapsed |