US4131488A
Expired / Lapsed
US
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Method of semiconductor solar energy device fabrication
Assignee: Motorola Solutions Inc
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Filing: 1977-04-25
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Granted: 1978-12-26
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Expires: 1997-04-25
Abstract
Abstract This disclosure relates to a semiconductor solar energy device which is of the PN-type and utilizes a dielectric anti-reflective coating on the side of the device that faces the sunlight. The fabrication techniques used in making this semiconductor device include the use of a rough or textured pyramid shaped silicon surface beneath the anti-reflective coating to increase solar cell efficiency. Also, ion implantation is used to form the PN junction in the device. The ion implanted region located on the side of the device that is subjected to the sunlight is configured in order to permit metal ohmic contact to be made thereto without shorting through the doped region during sintering of the metal contacts to the semiconductor substrate. The dielectric anti-reflective coating, in one embodiment, is a composite of silicon dioxide and silicon nitride layers. The device is designed to permit solder contacts to be made to the P and N regions thereof without possibility of shorting to semiconductor regions of opposite type conductivity.
Inventors
- 👤 Israel A. Lesk
- 👤 Robert A. Pryor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:54
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/202; H10P30/204; H10F; H10F77/00; H10F77/20; H10F77/206; H10F77/211; H10F77/30; H10F77/306; H10F77/311; H10F77/315; H10F77/70; H10F77/703; H10P30/21; H10P30/212; H10P30/22; H10P30/225; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/644; H10P50/69; H10P50/691; Y; Y02; Y02E; Y02E10/00; Y02E10/50
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
149 words
A process for forming a semiconductor solar energy device comprising the steps of: providing a silicon wafer of a first conductivity type with two major surfaces; introducing a doping impurity of said first conductivity type into both major surfaces simultaneously; forming an oxide layer on both major surfaces following the introduction of said doping impurities; removing said oxide layer from a first major surface of said wafer; treating said first major surface to form a textured pyramidal surface structure while masking a second major surface opposite said first major surface from said texture treating; forming a thin layer of silicon dioxide in contact with said first major surface; forming a thin layer of silicon nitride on said layer of silicon dioxide to form an antireflective coating; and forming a shallow layer of semiconductor material of a second conductivity type opposite said first conductivity type of said first major surface.
Claim 2
Dependent Claim
149 words
A process for forming a semiconductor solar energy device comprising the steps of: providing a silicon wafer of a first conductivity type with two major surfaces; introducing a doping impurity of said first conductivity type into both major surfaces simultaneously; forming an oxide layer on both major surfaces following the introduction of said doping impurities; removing said oxide layer from a first major surface of said wafer; treating said first major surface to form a textured pyramidal surface structure while masking a second major surface opposite said first major surface from said texture treating; forming a thin layer of silicon dioxide in contact with said first major surface; forming a thin layer of silicon nitride on said layer of silicon dioxide to form an antireflective coating; and forming a shallow layer of semiconductor material of a second conductivity type opposite said first conductivity type of said first major surface.
Claim 3
Dependent Claim
19 words
A process according to claim 1 where said thin layer of silicon dioxide is formed by thermal oxide growth.
Claim 4
Dependent Claim
22 words
A process according to claim 1 where said shallow layer of semiconductor material of second conductivity type is formed by ion implantation.
Claim 5
Dependent Claim
46 words
A process according to claim 1 further including: opening at least one hole through said silicon nitride and said silicon dioxide layers, ion implanting through said hole and said nitride and oxide layers to form said shallow layer of semiconductor material of said second conductivity type.
Claim 6
Dependent Claim
19 words
The process of claim 4, where said shallow layer is deeper under said hole than under said antireflective coating.
Claim 7
Dependent Claim
107 words
A process for the fabrication of a semiconductor solar energy comprising the steps of forming layers of enhanced conductivity on both surfaces of a semiconductor substrate of one type conductivity, selectively masking one of said surfaces, etching the other of said surfaces to remove one of said layers of enhanced conductivity and provide a pyramidal surface texture, forming a thin layer of silicon dioxide on said other surface and a thicker layer of silicon nitrite on said layer of silicon cioxide to provide an antireflective coating of said device, and forming a thin layer of second conductivity type opposite said one type conductivity under said antireflective coating.
Claim 8
Dependent Claim
107 words
A process for the fabrication of a semiconductor solar energy comprising the steps of forming layers of enhanced conductivity on both surfaces of a semiconductor substrate of one type conductivity, selectively masking one of said surfaces, etching the other of said surfaces to remove one of said layers of enhanced conductivity and provide a pyramidal surface texture, forming a thin layer of silicon dioxide on said other surface and a thicker layer of silicon nitrite on said layer of silicon cioxide to provide an antireflective coating of said device, and forming a thin layer of second conductivity type opposite said one type conductivity under said antireflective coating.
Claim 9
Dependent Claim
28 words
The process of claim 6, further including forming at least one aperture in said antireflective coating and forming a region of said second conductivity type beneath said aperture.
Claim 10
Dependent Claim
45 words
The process of claim 6, where the forming of said thin layer of second conductivity type is effected by ion implantation, and further including shadow masking of the periphery of said substrate to prevent said thin layer from extending to the sides of the substrate.
Claim 11
Dependent Claim
16 words
The process of claim 6 where said selective masking prevents the texturing of said one surface.
Claim 12
Dependent Claim
13 words
The process of claim 7, where said region is coextensive with said aperture.
Claim 13
Dependent Claim
24 words
The process of claim 7, where said region of second conductivity type penetrates said substrate further than said thin layer of second conductivity type.
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) | 1981-12-25 | 1982-06-26 | 1982-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-25 | 1986-06-26 | 1986-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-25 | 1990-06-26 | 1990-12-26 | $7700.00 | Window Closed / Lapsed |