US4198246A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulsed laser irradiation for reducing resistivity of a doped polycrystalline silicon film
Assignee: RCA Corp
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Filing: 1978-11-27
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Granted: 1980-04-15
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Expires: 1998-11-27
Abstract
Abstract A method of reducing the resistivity of a doped polycrystalline silicon film deposited on a substrate comprises the step of irradiating the film with a laser pulse having an energy density of less than about 1.5 joules per square centimeter.
Inventors
- 👤 Chung P. Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:23
CPC Classifications
H; H10; H10P; H10P95/00; H10P34/00; H10P34/40; H10P34/42; Y; Y10; Y10S; Y10S148/00; Y10S148/093; Y10S438/00; Y10S438/934
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
40 words
A method of reducing the resistivity of a doped polycrystalline silicon film disposed on a substrate comprising the step of irradiating said film with a laser pulse having an energy density of less than about 1.5 joules per square centimeter.
Claim 2
Independent Claim
40 words
A method of reducing the resistivity of a doped polycrystalline silicon film disposed on a substrate comprising the step of irradiating said film with a laser pulse having an energy density of less than about 1.5 joules per square centimeter.
Claim 3
Dependent Claim
23 words
A method as recited in claim 1 wherein said laser has a pulse duration time of between about 20 and about 40 nanoseconds.
Claim 4
Dependent Claim
39 words
A method as recited in claim 1 wherein said laser is a Q-switched Nd:glass laser having a pulse energy density of between about 0.5 and 1.5 joules per square centimeter, and a pulse duration time of about 30 nanoseconds.
Claim 5
Dependent Claim
39 words
A method as recited in claim 1 wherein said laser is a Q-switched ruby laser having a pulse energy density of between about 0.2 and 0.8 joules per square centimeter, and a pulse duration time of about 30 nanoseconds.
Claim 6
Dependent Claim
32 words
A method as recited in claim 1 wherein said substrate comprises a silicon wafer having a layer of silicon dioxide disposed thereon, said polycrystalline film being deposited on the silicon dioxide layer.
Claim 7
Dependent Claim
11 words
A structure produced in accordance with the method of claim 1.
Claim 8
Dependent Claim
42 words
A method as recited in claim 5 wherein said polycrystalline silicon film has a thickness of about 1 micrometer and is doped with N type conductivity modifiers to a dose of between about 1×10 15 and 1×10 16 atoms per square centimeter.
Claim 9
Dependent Claim
16 words
A method as recited in claim 7 wherein said N type conductivity modifiers comprise arsenic (As).
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) | 1983-04-15 | 1983-10-15 | 1984-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-15 | 1987-10-15 | 1988-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-15 | 1991-10-15 | 1992-04-15 | $7700.00 | Window Closed / Lapsed |