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US5466630A
Expired / Lapsed
US
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Silicon-on-insulator technique with buried gap
Assignee: United Microelectronics Corp
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Filing: 1994-08-05
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Granted: 1995-11-14
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Expires: 2014-08-05
Abstract
Abstract An silicon-on-insulator (SOI) isolation structure of a silicon substrate, which has a buried gap between active regions and the substrate, and supporting pillars formed of an insulating material to support the active regions. The buried gap is formed by etching an implanted buried silicon nitride layer. Since the dielectric constant of the buried gap is about 1, the dielectric effect and isolating effect of this structure are greatly improved.
Inventors
- 👤 Water Lur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:40
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10W; H10W10/00; H10W10/01; H10W10/061; H10W10/10; H10W10/181; H10W10/011; H10W10/014; H10W10/021; H10W10/17; H10W10/20
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
87 words
A method of forming an isolated structure on a semiconductor substrate, which method comprises the steps of: (a) forming a buried layer in said substrate to divide said substrate into a surface portion and a bottom portion; (b) forming a plurality of supporting pillars at positions in the surface portion and buried layer to support the surface portion on the bottom portion, the supporting pillars being formed of an insulating material which is different insulating material forming the buried layer; and (c) removing the remaining buried layer.
Claim 2
Independent Claim
87 words
A method of forming an isolated structure on a semiconductor substrate, which method comprises the steps of: (a) forming a buried layer in said substrate to divide said substrate into a surface portion and a bottom portion; (b) forming a plurality of supporting pillars at positions in the surface portion and buried layer to support the surface portion on the bottom portion, the supporting pillars being formed of an insulating material which is different insulating material forming the buried layer; and (c) removing the remaining buried layer.
Claim 3
Dependent Claim
61 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 1, including the steps of: (d) forming a plurality of holes in the surface portion which penetrates the surface portion to the buried layer; (e) dipping said substrate into an etchant to etch away the buried layer to define a gap; and (f) closing the holes.
Claim 4
Dependent Claim
29 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 2, wherein step (f) is performed by depositing an insulating material in the holes.
Claim 5
Dependent Claim
26 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 3, wherein the insulating in the holes material is silicon nitride.
Claim 6
Dependent Claim
26 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 3, wherein the insulating in the holes material is silicon oxide.
Claim 7
Dependent Claim
32 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 2, wherein the step (c) further includes forming an oxide layer on facing surfaces in said gap.
Claim 8
Dependent Claim
49 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 2, wherein the step (c) further includes: (c1) forming an oxide layer on facing surfaces of the surface portion and the bottom portion after the buried layer is removed; and (c2) annealing said substrate.
Claim 9
Dependent Claim
33 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 2, wherein the step (c) further includes: annealing said substrate after the buried silicon nitride layer is removed.
Claim 10
Dependent Claim
23 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 1, wherein the buried layer is silicon nitride.
Claim 11
Dependent Claim
30 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 9, wherein phosphoric acid is used as an etchant to etch away the buried layer.
Claim 12
Dependent Claim
24 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 9, wherein the pillars are formed from silicon oxide.
Claim 13
Dependent Claim
37 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 11, wherein the pillars are formed by forming trenches in the substrate and buried layer and filling said trenches with silicon oxide.
Claim 14
Dependent Claim
31 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 11, wherein step (c) further includes forming an oxide layer on facing surfaces in said gap.
Claim 15
Dependent Claim
47 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 1, wherein the step (c) further includes forming an oxide layer on facing surfaces of the surface portion and the bottom, portion after the buried layer is removed; and annealing said substrate.
Claim 16
Dependent Claim
32 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 1, wherein the step (c) further includes annealing said substrate after the buried layer has been removed.
Claim 17
Dependent Claim
62 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 1, wherein the step (a) is performed by implanting nitrogen ions into said substrate at 30 KeV to 200 KeV with a dosage between 1×10 18 to 3×10 18 atoms/cm 2 and then annealing said substrate at 1100° C. to 1300° C. for 1 to 5 hours.
Claim 18
Dependent Claim
42 words
A method of forming an isolated structure on a semiconductor substrate as claimed in claim 1, wherein step (b) is performed by etching said substrate in the buried layer at the positions by reactive ion etching, and then depositing an oxide therein.
References Cited (Backward Citations)
JPS62122143A
Cited
US5232866A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-11-13 | 1999-05-15 | 1999-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-13 | 2003-05-15 | 2003-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-13 | 2007-05-15 | 2007-11-14 | $7700.00 | Window Closed / Lapsed |