US4475955A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming integrated circuits bearing polysilicon of reduced resistance
Assignee: Harris Corp
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Filing: 1982-12-06
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Granted: 1984-10-09
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Expires: 2002-12-06
Abstract
Abstract A method for fabricating polysilicon of reduced resistance that may be incorporated in silicon integrated chip manufacturing processes which comprises coating a wafer bearing dielectrically isolated islands with an isolating layer, and depositing thereover a layer of polysilicon. On the surface of the polysilicon layer, a masking layer is formed, and coated with a metallic reflective layer. The portion of the reflective layer, and, optionally, the masking layer, overlaying the interisland area is removed, and the wafer is then exposed to a laser beam, transforming the polysilicon layer into the appropriate resistor material. The remaining metallic and/or masking layer may then be removed, the device exposed to a laser beam again, thereby transforming the polysilicon across the entire surface.
Inventors
- 👤 Vipin N. Patel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:38
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/40; H10D1/47; H10P; H10P95/00
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
120 words
A method of forming a layer of energy beam annealed polysilicon on an integrated circuit device precursor having regions of lower and higher energy beam reflection characteristics, wherein said regions of higher energy beam reflection characteristics are dielectrically isolated islands, and said regions of lower energy beam reflection characteristics are interisland areas of polycrystalline silicon positioned therebetween, comprising the steps of: forming an isolating layer on the surface of said precursor; forming a layer of polysilicon on said isolating layer; depositing a layer of material capable of reflecting high energy beams over said polysilicon layer; removing a portion of said reflecting material overlaying a region of lower energy beam reflection characteristics; and exposing the precursor to a high energy beam.
Claim 2
Independent Claim
120 words
A method of forming a layer of energy beam annealed polysilicon on an integrated circuit device precursor having regions of lower and higher energy beam reflection characteristics, wherein said regions of higher energy beam reflection characteristics are dielectrically isolated islands, and said regions of lower energy beam reflection characteristics are interisland areas of polycrystalline silicon positioned therebetween, comprising the steps of: forming an isolating layer on the surface of said precursor; forming a layer of polysilicon on said isolating layer; depositing a layer of material capable of reflecting high energy beams over said polysilicon layer; removing a portion of said reflecting material overlaying a region of lower energy beam reflection characteristics; and exposing the precursor to a high energy beam.
Claim 3
Dependent Claim
24 words
The method of claim 1, further comprising removing the remaining reflective material and exposing the precursor to an high energy beam a second time.
Claim 4
Dependent Claim
14 words
The method of claim 1, wherein said high energy beam is a laser beam.
Claim 5
Dependent Claim
15 words
The method of claim 1, wherein said reflecting layer is comprised of a reflective metal.
Claim 6
Dependent Claim
22 words
The method of claim 4, wherein said metal is selected from the group consisting of W, Mo, Ta, Ti and mixtures thereof.
Claim 7
Dependent Claim
10 words
The method of claim 4, wherein said metal is aluminum.
Claim 8
Dependent Claim
19 words
The method of claim 1, wherein said layer of polysilicon is formed through low pressure chemical vapor deposition processes.
Claim 9
Independent Claim
132 words
A method of forming a layer of energy beam annealed polysilicon on an integrated circuit device precursor having regions of lower and higher energy beam reflection characteristics wherein said regions of higher energy beam reflection characteristics are dielectrically isolated islands, and said regions of lower energy beam reflection characteristics are interisland areas of polycrystalline silicon positioned therebetween, comprising the steps of: forming an isolated layer on the surface of said precursor; forming a layer of polysilicon on said isolating layer; forming a masking layer on said polysilicon layer; depositing a layer of material capable of reflecting high energy beams over said masking layer; removing a portion of said reflective material and said masking layer overlaying a region of lower energy beam reflection characteristics; and exposing the precursor to a high energy beam.
Claim 10
Independent Claim
132 words
A method of forming a layer of energy beam annealed polysilicon on an integrated circuit device precursor having regions of lower and higher energy beam reflection characteristics wherein said regions of higher energy beam reflection characteristics are dielectrically isolated islands, and said regions of lower energy beam reflection characteristics are interisland areas of polycrystalline silicon positioned therebetween, comprising the steps of: forming an isolated layer on the surface of said precursor; forming a layer of polysilicon on said isolating layer; forming a masking layer on said polysilicon layer; depositing a layer of material capable of reflecting high energy beams over said masking layer; removing a portion of said reflective material and said masking layer overlaying a region of lower energy beam reflection characteristics; and exposing the precursor to a high energy beam.
Claim 11
Dependent Claim
27 words
The method of claim 8, further comprising removing the remaining reflective material and masking layer and exposing the precursor to a high energy beam a second time.
Claim 12
Dependent Claim
14 words
The method of claim 8, wherein said high energy beam is a laser beam.
Claim 13
Dependent Claim
15 words
The method of claim 8, wherein said reflective layers is comprised of a reflective metal.
Claim 14
Dependent Claim
22 words
The method of claim 11, wherein said metal is selected from the group consisting of W, Mo, Ta, Ti and mixtures thereof.
Claim 15
Dependent Claim
10 words
The method of claim 11, wherein said metal is aluminum.
Claim 16
Dependent Claim
19 words
The method of claim 8, wherein said layer of polysilicon is deposited through low pressure chemical vapor deposition processes.
Claim 17
Independent Claim
110 words
A method of forming a layer of energy beam annealed polysilicon on an integrated circuit device precursor having regions of lower and higher energy beam reflection characteristics, comprising the steps of: forming an isolating layer on the surface of said precursor; forming a layer of polysilicon on said isolating layer, said polysilicon layer being formed over at least a portion of said regions of lower and higher energy beam reflection characteristics; selectively exposing a portion of said layer of polysilicon overlaying said region of lower energy beam reflection characteristics to an energy beam a first time; and non-selectively exposing said layer of polysilicon to an energy beam a second time.
Claim 18
Independent Claim
110 words
A method of forming a layer of energy beam annealed polysilicon on an integrated circuit device precursor having regions of lower and higher energy beam reflection characteristics, comprising the steps of: forming an isolating layer on the surface of said precursor; forming a layer of polysilicon on said isolating layer, said polysilicon layer being formed over at least a portion of said regions of lower and higher energy beam reflection characteristics; selectively exposing a portion of said layer of polysilicon overlaying said region of lower energy beam reflection characteristics to an energy beam a first time; and non-selectively exposing said layer of polysilicon to an energy beam a second time.
Claim 19
Dependent Claim
13 words
The method of claim 15, wherein said energy beam is a laser beam.
Claim 20
Dependent Claim
19 words
The method of claim 15, wherein said layer of polysilicon is deposited through low pressure chemical vapor deposition processes.
References Cited (Backward Citations)
US4179310A
Cited
US4309224A
Cited
US4214918A
Cited
US4198246A
Cited
US4292091A
Cited
US4272880A
Cited
US4229502A
Cited
US4269631A
Cited
US4299024A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-09 | 1988-04-09 | 1988-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-09 | 1992-04-09 | 1992-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-09 | 1996-04-09 | 1996-10-09 | $7700.00 | Window Closed / Lapsed |