Patent US3328189A successfully refreshed from Google Patents.
US4052252A
Expired / Lapsed
US
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Liquid phase epitaxial growth with interfacial temperature difference
Assignee: RCA Corp
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Filing: 1975-04-04
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Granted: 1977-10-04
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Expires: 1995-04-04
Abstract
Abstract A thin layer of semiconductor material with an extremely smooth surface can be grown on a substrate by liquid phase epitaxy. When the growing solution contacts the surface of the substrate, the substrate is at a lower temperature than the solution. The temperature difference should be less than 1° C and depends upon the desired degree of smoothness. Both the substrate and the solution are then cooled to permit deposition of the layer.
Inventors
- 👤 Harry Francis Lockwood
- 👤 Michael Ettenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:43
CPC Classifications
C; C30; C30B; C30B19/00; C30B19/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
103 words
A method for growing a layer of crystalline semiconductor material by liquid phase epitaxy comprising the steps of: heating a charge composed of a semiconductor material and a solvent to melt the charge and form a solution of the semiconductor material in the solvent; heating a substrate to a lower temperature than the solution where the temperature difference is less than 1° C; bringing the substrate into contact with the solution; cooling the solution and substrate at the same rate to deposit a layer of semiconductor material onto the substrate; and removing the substrate from contact with the solution after a predetermined interval.
Claim 2
Independent Claim
103 words
A method for growing a layer of crystalline semiconductor material by liquid phase epitaxy comprising the steps of: heating a charge composed of a semiconductor material and a solvent to melt the charge and form a solution of the semiconductor material in the solvent; heating a substrate to a lower temperature than the solution where the temperature difference is less than 1° C; bringing the substrate into contact with the solution; cooling the solution and substrate at the same rate to deposit a layer of semiconductor material onto the substrate; and removing the substrate from contact with the solution after a predetermined interval.
Claim 3
Dependent Claim
22 words
A method as in claim 1 wherein the temperature differnce between the substrate and the solution is between 0.1° and 0.2° C.
Claim 4
Dependent Claim
18 words
The method as in claim 1 wherein the rate of cooling is less than 1° C per minute.
Claim 5
Independent Claim
136 words
A method for growing multiple layers of crystalline semiconductor material by liquid phase epitaxy, said method comprising the steps of: heating a plurality of charges each composed of semiconductor material and a solvent, to melt the charge and form a solution of the semiconductor material in the solvent, each successive solution being maintained at a higher temperature, the temperature difference being less than 1° C; heating a substrate to a lower temperature than the lowest temperature of said solutions, the temperature difference being less than 1° C; bringing the substrate successively into contact with each solution for a predetermined interval, commencing with the coolest and progressing to the hottest solution; and cooling the solutions and the substrate at the same rate while they are in contact to deposit layers of the semiconductor material onto the substrate.
Claim 6
Independent Claim
136 words
A method for growing multiple layers of crystalline semiconductor material by liquid phase epitaxy, said method comprising the steps of: heating a plurality of charges each composed of semiconductor material and a solvent, to melt the charge and form a solution of the semiconductor material in the solvent, each successive solution being maintained at a higher temperature, the temperature difference being less than 1° C; heating a substrate to a lower temperature than the lowest temperature of said solutions, the temperature difference being less than 1° C; bringing the substrate successively into contact with each solution for a predetermined interval, commencing with the coolest and progressing to the hottest solution; and cooling the solutions and the substrate at the same rate while they are in contact to deposit layers of the semiconductor material onto the substrate.
Claim 7
Dependent Claim
16 words
A method as in claim 4 wherein the temperature differences are between 0.1° and 0.2° C.
Claim 8
Dependent Claim
18 words
The method as in claim 4 wherein the rate of cooling is less than 1° C per minute.
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) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |