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Patent US6071817A successfully refreshed from Google Patents.
US6071817A
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Isolation method utilizing a high pressure oxidation
Assignee: Bell Semiconductor LLC
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Filing: 1998-03-23
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Granted: 2000-06-06
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Expires: 2018-03-23
Abstract
Abstract The present invention applies a silicon nitride or the like as a mask over portions of a substrate, such as an active region, where oxide growth is undesired. Thereafter, without the formation of a recess in the substrate, a high pressure oxidation process is used to grow an oxide, preferably in a furnace. The oxide thus grows into the non-masked areas of the substrate, as well as over the silicon nitride used as a mask. Thereafter, a chemical-mechanical polish is used to etch away undesired oxide, with the silicon nitride being used as an endpoint to terminate the polish operation.
Inventors
- 👤 Derryl D. J. Allman
- 👤 Kenneth P. Fuchs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:05
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6322; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10W10/0121; H10W10/10; H10W10/13; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
105 words
A method of forming an oxidation layer in a substrate comprising the steps of: applying a protective layer as a mask to portions of a top surface of said substrate where oxidation is to be prevented to obtain a masked surface having unmasked portions, said protective layer being capable of withstanding a chemical mechanical polishing; oxidizing said masked surface so that oxide regions are created within said substrate at locations corresponding to said unmasked portions; and removing a top portion of said oxide regions using a chemical-mechanical polishing operation and a pad to obtain isolation regions, wherein pad support is provided by said protective layer.
Claim 2
Independent Claim
105 words
A method of forming an oxidation layer in a substrate comprising the steps of: applying a protective layer as a mask to portions of a top surface of said substrate where oxidation is to be prevented to obtain a masked surface having unmasked portions, said protective layer being capable of withstanding a chemical mechanical polishing; oxidizing said masked surface so that oxide regions are created within said substrate at locations corresponding to said unmasked portions; and removing a top portion of said oxide regions using a chemical-mechanical polishing operation and a pad to obtain isolation regions, wherein pad support is provided by said protective layer.
Claim 3
Dependent Claim
32 words
A method according to claim 1 wherein said protective layer is comprised of silicon nitride, said substrate is silicon, and a buffer layer is disposed between said protective layer and said substrate.
Claim 4
Dependent Claim
27 words
A method according to claim 1 wherein said step of oxidizing uses a high pressure oxidation process in which said oxidation pressure is greater than 2 atmospheres.
Claim 5
Dependent Claim
24 words
A method according to claim 3 wherein said oxidizing step grows said oxide regions using a temperature that is less than 1100 degrees F.
Claim 6
Dependent Claim
17 words
A method according to claim 4 wherein said oxidizing step takes 2 to 600 minutes to complete.
Claim 7
Dependent Claim
17 words
A method according to claim 4 wherein said oxidizing step takes 20 to 60 minutes to complete.
Claim 8
Dependent Claim
26 words
A method according to claim 1, wherein said substrate is a wafer, and said protective layer is substantially uniformally disposed over various locations on said wafer.
Claim 9
Dependent Claim
33 words
A method according to claim 7 wherein said step of applying said protective layer results in unmasked portions having length and width dimensions that are larger than a thickness of said isolation regions.
Claim 10
Dependent Claim
15 words
A method according to claim 1 wherein said oxidizing step uses oxygen, without any hydrogen.
Claim 11
Dependent Claim
24 words
A method according to claim 1 wherein said oxidizing step grows said oxide regions using a temperature that is less than 1100 degrees F.
Claim 12
Dependent Claim
23 words
A method according to claim 1 further including the step of cleaning said masked surface with hydrogen prior to said step of oxidizing.
Claim 13
Dependent Claim
27 words
A method according to claim 1 wherein said protective layer is comprised of polysilicon and a buffer layer is disposed between said protective layer and said substrate.
Claim 14
Dependent Claim
12 words
A method according to claim 1 wherein said protective layer is oxynitride.
Claim 15
Dependent Claim
16 words
A method according to claim 1 wherein said substrate is not subjected to a plasma etch.
Claim 16
Dependent Claim
30 words
A method according to claim 1 further comprising the step of forming a trench in said substrate at locations corresponding to said unmasked portions prior to said step of oxidizing.
Claim 17
Dependent Claim
17 words
A method according to claim 15 wherein sidewalls of said trench are protected using nitride protective layer.
Claim 18
Dependent Claim
25 words
A method according to claim 1 wherein said oxide regions grows over said unmasked portions, but no substantial oxide growth occurs over said masked surface.
Claim 19
Dependent Claim
24 words
A method according to claim 1 wherein a top surface of said isolation regions substantially corresponds to a top surface of said protective layer.
Claim 20
Independent Claim
117 words
A method of forming an oxidation layer in a substrate comprising the steps of: applying a protective layer as a mask to portions of a top surface of said substrate where oxidation is to be prevented to obtain a masked surface having unmasked portions, said protective layer being capable of withstanding a chemical mechanical polishing and inhibiting oxide growth over a top surface of said protective layer; oxidizing said masked surface so that oxide regions are created within said substrate at locations corresponding to said unmasked portions; and removing a top portion of said oxide regions using a chemical-mechanical polishing operation and a pad to obtain isolation regions, wherein pad support is provided by said protective layer.
Claim 21
Independent Claim
117 words
A method of forming an oxidation layer in a substrate comprising the steps of: applying a protective layer as a mask to portions of a top surface of said substrate where oxidation is to be prevented to obtain a masked surface having unmasked portions, said protective layer being capable of withstanding a chemical mechanical polishing and inhibiting oxide growth over a top surface of said protective layer; oxidizing said masked surface so that oxide regions are created within said substrate at locations corresponding to said unmasked portions; and removing a top portion of said oxide regions using a chemical-mechanical polishing operation and a pad to obtain isolation regions, wherein pad support is provided by said protective layer.
Claim 22
Dependent Claim
27 words
A method according to claim 19 wherein said step of oxidizing uses a high pressure oxidation process in which said oxidation pressure is greater than 2 atmospheres.
Claim 23
Dependent Claim
24 words
A method according to claim 20 wherein said oxidizing step grows said oxide regions using a temperature that is less than 1100 degrees F.
Claim 24
Dependent Claim
15 words
A method according to claim 19 wherein said oxidizing step uses oxygen, without any hydrogen.
Claim 25
Dependent Claim
24 words
A method according to claim 19 wherein said oxidizing step grows said oxide regions using a temperature that is less than 1100 degrees F.
Claim 26
Dependent Claim
23 words
A method according to claim 19 further including the step of cleaning said masked surface with hydrogen prior to said step of oxidizing.
Claim 27
Dependent Claim
17 words
A method according to claim 19 wherein said oxidizing step takes 2 to 600 minutes to complete.
Claim 28
Dependent Claim
17 words
A method according to claim 19 wherein said oxidizing step takes 20 to 60 minutes to complete.
Claim 29
Dependent Claim
16 words
A method according to claim 19 wherein said substrate is not subjected to a plasma etch.
Claim 30
Dependent Claim
24 words
A method according to claim 19 wherein a top surface of said isolation regions substantially corresponds to a top surface of said protective layer.
Claim 31
Dependent Claim
30 words
A method according to claim 19 further comprising the step of forming a trench in said substrate at locations corresponding to said unmasked portions prior to said step of oxidizing.
Claim 32
Dependent Claim
18 words
A method according to claim 29 wherein sidewalls of said trench are protected using a nitride protective layer.
Claim 33
Dependent Claim
27 words
A method according to claim 29 wherein said step of oxidizing uses a high pressure oxidation process in which said oxidation pressure is greater than 2 atmospheres.
Claim 34
Dependent Claim
24 words
A method according to claim 31 wherein said oxidizing step grows said oxide regions using a temperature that is less than 1100 degrees F.
Claim 35
Dependent Claim
15 words
A method according to claim 29 wherein said oxidizing step uses oxygen, without any hydrogen.
Claim 36
Dependent Claim
24 words
A method according to claim 29 wherein said oxidizing step grows said oxide regions using a temperature that is less than 1100 degrees F.
Claim 37
Dependent Claim
23 words
A method according to claim 29 further including the step of cleaning said masked surface with hydrogen prior to said step of oxidizing.
Claim 38
Dependent Claim
32 words
A method according to claim 19 wherein said protective layer is comprised of silicon nitride, said substrate is silicon, and a buffer layer is disposed between said protective layer and said substrate.
Claim 39
Dependent Claim
27 words
A method according to claim 19 wherein said protective layer is comprised of polysilicon and a buffer layer is disposed between said protective layer and said substrate.
Claim 40
Dependent Claim
12 words
A method according to claim 19 wherein said protective layer is oxynitride.
References Cited (Backward Citations)
US5175123A
Cited
US5114875A
Cited
US5466628A
Cited
US5275974A
Cited
US5401692A
Cited
US5665620A
Cited
US5455194A
Cited
US5786263A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-06-06 | 2003-12-06 | 2004-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-06-06 | 2007-12-06 | 2008-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-06-06 | 2011-12-06 | 2012-06-06 | $7700.00 | Window Closed / Lapsed |