US4229502A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-resistivity polycrystalline silicon film
Assignee: RCA Corp
•
Filing: 1979-08-10
•
Granted: 1980-10-21
•
Expires: 1999-08-10
Abstract
Abstract A method of fabricating a low-resistivity polycrystalline silicon film deposited on a substrate comprises the steps of doping the polycrystalline silicon film with boron in situ while depositing the film, to a concentration greater than 1x1020 atoms/cm3, and then irradiating the film with a laser pulse. The present method may be utilized to fabricate a polycrystalline silicon film having a relatively small temperature coefficient of resistivity by electrically connecting a first irradiated part of the film with a second non-irradiated part in a manner allowing the two parts, having different temperature coefficients of resistivity, to compensate each other.
Inventors
- 👤 Chung P. Wu
- 👤 Ronald K. Smeltzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:38
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/56; H; H10; H10P; H10P14/00; H10P14/40; H10P14/416; H10P34/00; H10P34/40; H10P34/42; Y; Y10; Y10S; Y10S438/00; Y10S438/934
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
60 words
In a method of fabricating a low-resistivity polycrystalline silicon film including the step of depositing said film on a substrate, the improvement in said method comprising the steps of: doping said polycrystalline silicon film with boron in situ during said depositing step to a concentration greater than 1×10 20 atoms/cm 3 and then irradiating said film with a laser pulse.
Claim 2
Dependent Claim
60 words
In a method of fabricating a low-resistivity polycrystalline silicon film including the step of depositing said film on a substrate, the improvement in said method comprising the steps of: doping said polycrystalline silicon film with boron in situ during said depositing step to a concentration greater than 1×10 20 atoms/cm 3 and then irradiating said film with a laser pulse.
Claim 3
Dependent Claim
31 words
A method as recited in claim 1 wherein said doping step is performed so that the concentration of boron in said polycrystalline silicon film is about 2×10 21 atoms/cm 3 .
Claim 4
Dependent Claim
27 words
A method as recited in claim 1 wherein said laser pulse has a power density of between about 7.5 MW/cm 2 and about 80 MW/cm 2 .
Claim 5
Dependent Claim
24 words
A method as recited in claim 1 wherein said laser is a Q-switched ruby laser having a pulse duration time of about 30 nanoseconds.
Claim 6
Dependent Claim
33 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 silicon film being deposited on the silicon dioxide layer.
Claim 7
Dependent Claim
19 words
A method as recited in claim 5 wherein said polycrystalline silicon film has a thickness of about 0.6 μm.
Claim 8
Dependent Claim
11 words
A structure produced in accordance with the method of claim 1.
Claim 9
Dependent Claim
105 words
In a method of fabricating a polycrystalline silicon film having a relatively small temperature coefficient of resistivity, including the step of depositing said film on a substrate, the improvement in said method comprising the steps of: doping said polycrystalline silicon film with boron in situ during said depositing step to a concentration greater than 1×10 20 atoms/cm 3 , irradiating a first part of said doped film with a laser pulse, and electrically connecting said first part of said film with a second nonirradiated part of said film in a manner allowing the two parts, having different temperature coefficients of resistivity, to compensate each other.
Claim 10
Dependent Claim
105 words
In a method of fabricating a polycrystalline silicon film having a relatively small temperature coefficient of resistivity, including the step of depositing said film on a substrate, the improvement in said method comprising the steps of: doping said polycrystalline silicon film with boron in situ during said depositing step to a concentration greater than 1×10 20 atoms/cm 3 , irradiating a first part of said doped film with a laser pulse, and electrically connecting said first part of said film with a second nonirradiated part of said film in a manner allowing the two parts, having different temperature coefficients of resistivity, to compensate each other.
Claim 11
Dependent Claim
31 words
A method as recited in claim 8 wherein said doping step is performed so that the concentration of boron in said polycrystalline silicon film is about 2×10 21 atoms/cm 3 .
Claim 12
Dependent Claim
27 words
A method as recited in claim 8 wherein said laser pulse has a power density of between about 7.5 MW/cm 2 and about 80 MW/cm 2 .
Claim 13
Dependent Claim
11 words
A structure produced in accordance with the method of claim 8.
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) | 1983-10-21 | 1984-04-21 | 1984-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-21 | 1988-04-21 | 1988-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-21 | 1992-04-21 | 1992-10-21 | $7700.00 | Window Closed / Lapsed |