US6037228A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of fabricating self-aligned contact window which includes forming a undoped polysilicon spacer that extends into a recess of the gate structure
Assignee: United Microelectronics Corp
•
Filing: 1999-02-12
•
Granted: 2000-03-14
•
Expires: 2019-02-12
Abstract
Abstract A method of fabricating a self-aligned contact window is described. A gate oxide layer, a conductive layer, a first oxide layer and an undoped polysilicon layer are successively formed on a substrate. These layers above are patterned to form a gate structure. A water clean step is performed, producing a recess in the first oxide layer. A second oxide layer is thermally formed on the surface of the gate structure. An undoped polysilicon spacer is formed on the sidewall of the gate structure and a portion of the undoped polysilicon spacer extends into the recess of the first oxide layer. A dielectric layer is formed over the substrate and using the undoped polysilicon spacer as an etching stop, a self-aligned contact window is formed to expose the source/drain region.
Inventors
- 👤 Shih-Ying Hsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:11
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/069; Y; Y10; Y10S; Y10S257/00; Y10S257/90
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
129 words
A method of fabricating a self-aligned contact window, comprising: providing a substrate having a gate oxide layer; forming a conductive layer, a first oxide layer and a first undoped polysilicon layer on the substrate; patterning the first undoped polysilicon layer, the first oxide layer and the conductive layer to form a gate structure having a surface; removing a portion of the first oxide layer to form a recess therein; forming a second oxide layer on the surface of the gate structure; forming an undoped polysilicon spacer on the sidewall of the gate structure such that the undoped polysilicon spacer extends into the recess of the first oxide layer; forming a dielectric layer over the substrate; and forming a self-aligned contact window within the dielectric layer to expose the substrate.
Claim 2
Independent Claim
129 words
A method of fabricating a self-aligned contact window, comprising: providing a substrate having a gate oxide layer; forming a conductive layer, a first oxide layer and a first undoped polysilicon layer on the substrate; patterning the first undoped polysilicon layer, the first oxide layer and the conductive layer to form a gate structure having a surface; removing a portion of the first oxide layer to form a recess therein; forming a second oxide layer on the surface of the gate structure; forming an undoped polysilicon spacer on the sidewall of the gate structure such that the undoped polysilicon spacer extends into the recess of the first oxide layer; forming a dielectric layer over the substrate; and forming a self-aligned contact window within the dielectric layer to expose the substrate.
Claim 3
Dependent Claim
14 words
The method according to claim 1, wherein the first oxide layer includes TEOS oxide.
Claim 4
Dependent Claim
16 words
The method according to claim 2, wherein the TEOS oxide is formed by chemical vapor deposition.
Claim 5
Dependent Claim
19 words
The method according to claim 1, wherein a portion of the first oxide layer is removed by wet cleaning.
Claim 6
Dependent Claim
16 words
The method according to claim 4, wherein the wet cleaning is performed in a HF solution.
Claim 7
Dependent Claim
16 words
The method according to claim 1, wherein the second oxide layer is formed by thermal oxidation.
Claim 8
Dependent Claim
44 words
The method according to claim 1, wherein forming the undoped polysilicon spacer further comprises: forming a second undoped polysilicon layer over the substrate; and etching back the second undoped polysilicon layer to form an undoped polysilicon spacer on the sidewall of the gate structure.
Claim 9
Dependent Claim
29 words
The method according to claim 1, wherein forming the self-aligned contact window further comprises using the first undoped polysilicon layer as an etching stop to pattern the dielectric layer.
Claim 10
Dependent Claim
20 words
The method according to claim 1, wherein after forming the undoped polysilicon layer further comprises forming an anti-reflectivity coating layer.
Claim 11
Dependent Claim
18 words
The method according to claim 9, wherein the anti-reflectivity coating layer includes silicon-oxy-nitride (SiO x N y ).
Claim 12
Dependent Claim
28 words
The method according to claim 1, wherein after forming the second oxide layer further comprises forming a lightly doped source/drain region in the substrate beside the gate structure.
Claim 13
Dependent Claim
28 words
The method according to claim 1, wherein after forming the polysilicon spacer further comprises forming a heavily doped source/drain region in the substrate beside the undoped polysilicon spacer.
Claim 14
Dependent Claim
22 words
The method according to claim 1, wherein the thickness of the first oxide layer is in a range of about 300-700 angstroms.
Claim 15
Dependent Claim
23 words
The method according to claim 1, wherein the thickness of the first undoped polysilicon layer is in a range of about 300-600 angstroms.
Claim 16
Dependent Claim
22 words
The method according to claim 1, wherein the thickness of the second oxide layer is in a range of about 100-150 angstroms.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-03-14 | 2003-09-13 | 2004-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-03-14 | 2007-09-13 | 2008-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-03-14 | 2011-09-13 | 2012-03-14 | $7700.00 | Window Closed / Lapsed |