US6063689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming an isolation
Assignee: United Microelectronics Corp
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Filing: 1998-10-01
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Granted: 2000-05-16
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Expires: 2018-10-01
Abstract
Abstract A method for forming a shallow-trench isolation starts with forming a polysilicon layer, which has less stress, as the mask layer for patterning the trench on a provided substrate. An oxide layer is then formed to cover the polysilicon layer and fill the trench. The oxide layer is then removed by first performing a chemical mechanical polishing process to remove a portion of the oxide layer, wherein the remains of the oxide layer still covers the polysilicon layer and fills the trench. After that, an etching back process is performed to remove the oxide layer from the top of the polysilicon layer to form the oxide plug, which is used as an isolation.
Inventors
- 👤 Coming Chen
- 👤 Water Lur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:33
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/014; H10W10/0143; H10W10/10; H10W10/17; Y; Y10; Y10S; Y10S148/00; Y10S148/05
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
138 words
A method for forming a shallow-trench isolation, the method comprising: providing a substrate; forming a mask layer on the substrate; patterning the mask layer and the substrate to form a trench; forming an oxide layer on the mask layer and in the trench; performing a chemical mechanical polishing process to remove a portion of the oxide layer, wherein a remaining portion of the oxide layer still covers the mask layer and the trench; after the chemical mechanical polishing process is performed, performing an etching back process to remove the remaining portion of the oxide layer from the top of the mask layer by using the mask layer as an etching stop, wherein the etching back process is capable of preventing scratch formation on a surface of the oxide layer; and removing the mask layer to expose the substrate.
Claim 2
Independent Claim
138 words
A method for forming a shallow-trench isolation, the method comprising: providing a substrate; forming a mask layer on the substrate; patterning the mask layer and the substrate to form a trench; forming an oxide layer on the mask layer and in the trench; performing a chemical mechanical polishing process to remove a portion of the oxide layer, wherein a remaining portion of the oxide layer still covers the mask layer and the trench; after the chemical mechanical polishing process is performed, performing an etching back process to remove the remaining portion of the oxide layer from the top of the mask layer by using the mask layer as an etching stop, wherein the etching back process is capable of preventing scratch formation on a surface of the oxide layer; and removing the mask layer to expose the substrate.
Claim 3
Dependent Claim
30 words
The method of claim 1, wherein the step of forming the mask layer further comprises forming a pad oxide layer on the substrate before the formation of the mask layer.
Claim 4
Dependent Claim
11 words
The method of claim 1, wherein the mask layer includes polysilicon.
Claim 5
Dependent Claim
19 words
The method of claim 1, wherein the step of forming the oxide layer includes a chemical vapor deposition process.
Claim 6
Dependent Claim
30 words
The method of claim 1, wherein the step of forming the oxide layer further comprises forming a linear oxide layer in the trench before the formation of the oxide layer.
Claim 7
Dependent Claim
18 words
The method of claim 1, wherein the step of removing the mask layer includes a dry etching process.
Claim 8
Independent Claim
117 words
A method for forming a shallow-trench isolation, the method comprising: providing a substrate; forming a polysilicon layer on the substrate; patterning the polysilicon layer and the substrate to form a trench; forming an oxide layer on the polysilicon layer and in the trench; polishing a portion of the oxide layer, wherein a remaining portion of the oxide layer still covers the polysilicon layer and the trench, wherein at least a scratche is formed on a surface of the oxide layer; and after the polishing step is performed, etching the remaining portion of the oxide layer from the top of the polysilicon layer to expose the polysilicon layer, wherein the etching step is capable of removing the scratch.
Claim 9
Independent Claim
117 words
A method for forming a shallow-trench isolation, the method comprising: providing a substrate; forming a polysilicon layer on the substrate; patterning the polysilicon layer and the substrate to form a trench; forming an oxide layer on the polysilicon layer and in the trench; polishing a portion of the oxide layer, wherein a remaining portion of the oxide layer still covers the polysilicon layer and the trench, wherein at least a scratche is formed on a surface of the oxide layer; and after the polishing step is performed, etching the remaining portion of the oxide layer from the top of the polysilicon layer to expose the polysilicon layer, wherein the etching step is capable of removing the scratch.
Claim 10
Dependent Claim
30 words
The method of claim 7, wherein the step of forming the polysilicon layer further comprises forming a pad oxide layer on the substrate before the formation of the polysilicon layer.
Claim 11
Dependent Claim
19 words
The method of claim 7, wherein the step of forming the oxide layer includes a chemical vapor deposition process.
Claim 12
Dependent Claim
30 words
The method of claim 7, wherein the step of forming the oxide layer further comprises forming a linear oxide layer in the trench before the formation of the oxide layer.
Claim 13
Dependent Claim
21 words
The method of claim 7, wherein the step of polishing the portion of the oxide layer includes s chemical mechanical polishing.
Claim 14
Dependent Claim
22 words
The method of claim 7, wherein the step of etching the remaining portion of the oxide layer includes an etching back process.
Claim 15
Dependent Claim
22 words
The method of claim 7, wherein the step of etching the remaining portion of the oxide layer includes a dry etching process.
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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) | 2003-05-16 | 2003-11-15 | 2004-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-05-16 | 2007-11-15 | 2008-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-05-16 | 2011-11-15 | 2012-05-16 | $7700.00 | Window Closed / Lapsed |