US5330918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming a high voltage silicon-on-sapphire photocell array
Assignee: United States Department of the Navy
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Filing: 1992-08-31
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Granted: 1994-07-19
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Expires: 2012-08-31
Abstract
Abstract A method is provided for forming a multi-cell photovoltaic circuit on an insulating substrate, comprising the steps of: forming a photovoltaic junction between p-type and n-type layers in a silicon wafer; bonding the silicon wafer to an insulating substrate after forming the photovoltaic junction; patterning the silicon wafer to produce isolated photovoltaic cells; and electrically interconnecting the photovoltaic cells.
Inventors
- 👤 Wadad B. Dubbelday
- 👤 Larry D. Flesner
- 👤 George P. Imthurn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:57
CPC Classifications
H; H10; H10F; H10F19/00; H10F19/20; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y10; Y10S; Y10S148/00; Y10S148/012; Y10S438/00; Y10S438/977
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
226 words
A method for forming a multi-cell photovoltaic circuit on an insulating substrate, comprising the steps of: forming a first silicon layer having a first concentration of a first dopant with a first polarity on a silicon wafer having a second concentration of a second dopant with a second polarity opposite said first polarity to create a photovoltaic junction; forming a second silicon layer on said first silicon layer, said second silicon layer having a third concentration of a third dopant having said first polarity, where said third concentration is greater than said first concentration of said first dopant; forming a silicon dioxide layer on said second silicon layer by thermal oxidation; bonding an insulating substrate to said silicon dioxide layer to create a bonded wafer; thinning said silicon wafer to form a thinned silicon layer; etching said bonded wafer to form a plurality of separate photodiodes having sloped sidewalls and to expose selected regions of said insulating substrate; forming an insulting silicon dioxide layer on said selected regions of said insulating substrate and on said separate photodiodes; exposing selected regions of said thinned silicon layer and regions of said second silicon layer of each of said photodiodes; and forming metal interconnects between said exposed selected regions of said thinned silicon layer of one of said photodiodes with said second silicon layer of another of said photodiodes.
Claim 2
Independent Claim
226 words
A method for forming a multi-cell photovoltaic circuit on an insulating substrate, comprising the steps of: forming a first silicon layer having a first concentration of a first dopant with a first polarity on a silicon wafer having a second concentration of a second dopant with a second polarity opposite said first polarity to create a photovoltaic junction; forming a second silicon layer on said first silicon layer, said second silicon layer having a third concentration of a third dopant having said first polarity, where said third concentration is greater than said first concentration of said first dopant; forming a silicon dioxide layer on said second silicon layer by thermal oxidation; bonding an insulating substrate to said silicon dioxide layer to create a bonded wafer; thinning said silicon wafer to form a thinned silicon layer; etching said bonded wafer to form a plurality of separate photodiodes having sloped sidewalls and to expose selected regions of said insulating substrate; forming an insulting silicon dioxide layer on said selected regions of said insulating substrate and on said separate photodiodes; exposing selected regions of said thinned silicon layer and regions of said second silicon layer of each of said photodiodes; and forming metal interconnects between said exposed selected regions of said thinned silicon layer of one of said photodiodes with said second silicon layer of another of said photodiodes.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein said insulating substrate includes a material selected from the group of consisting of sapphire, quartz, glass, and silicon dioxide on silicon.
Claim 4
Dependent Claim
51 words
The method of claim 2 wherein the step of bonding includes placing said insulating substrate in contact with said silicon dioxide layer; and then heating said insulating substrate and said silicon dioxide layer to a temperature of about 200° C. for a period which may range from 1 to 100 hours.
Claim 5
Dependent Claim
29 words
The method of claim 3 wherein the step of thinning said silicon wafer includes thinning said silicon wafer to a thickness in the range of 100 to 1000 nanometers.
Claim 6
Dependent Claim
22 words
The method of claim 3 wherein said first concentration of said first dopant is less than about 10 18 /cm 3 .
Claim 7
Dependent Claim
20 words
The method of claim 3 wherein said second concentration of said second dopant is about 10 19 /cm 3 .
Claim 8
Dependent Claim
20 words
The method of claim 3 wherein said third concentration of said third dopant is about 10 19 /cm 3 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-07-18 | 1998-01-17 | 1998-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-18 | 2002-01-17 | 2002-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-18 | 2006-01-17 | 2006-07-19 | $7700.00 | Window Closed / Lapsed |