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US3753801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of depositing expitaxial semiconductor layers from the liquid phase
Assignee: RCA Corp
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Filing: 1971-12-08
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Granted: 1973-08-21
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Expires: 1991-12-08
Abstract
Abstract One or more epitaxial layers of a semiconductor material are deposited on a substrate by providing for each epitaxial layer to be deposited a separate solution of a semiconductor material dissolved in a molten metal solvent. Each of the solutions is of a small volume and a weight is provided on each solution to spread the solution out in the form of a thin layer. The substrate is brought into contact with the solution and the solution is cooled to deposit the epitaxial layer on the substrate. Since the solution is in the form of a thin layer, only a minimum of platelets of the semiconductor material are formed in the solution during the deposition of the epitaxial layer so that the epitaxial layer has a smooth, even surface. To deposit a plurality of epitaxial layers on the substrate, the substrate is successively brought into contact with each solution which is then cooled to deposit an epitaxial layer. Each solution may be exactly saturated with the semiconductor material by bringing a body of semiconductor material into contact with the solution prior to bringing the substrate into contact with the solution.
Inventors
- 👤 H Lockwood
- 👤 D Marinelli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:35
CPC Classifications
C; C30; C30B; C30B19/00; C30B19/06; C30B19/063; C30B19/10; C30B19/106; H; H10; H10P; H10P95/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
23 words
The method in accordance with claim 1 in which the force is applied to the solution by placing a weight on the solution.
Claim 2
Dependent Claim
67 words
The method in accordance with claim 2 in which the confined space has a bottom surface of an area at least as large as the area of the surface of the substrate on which the epitaxial layer is deposited and the weight applies a force on the solution so as to spread the solution as a thin layer over the entire bottom surface of the confined space.
Claim 3
Dependent Claim
65 words
The method in accordance with claim 3 in which prior to bringing the surface of the substrate into contact with the solution a body of the semiconductor material is brought into contact with the solution so as to exactly saturate the solution at the then temperature of the solution, and then the surface of the substrate is brought into contact with the exactly saturated solution.
Claim 4
Dependent Claim
26 words
The method in accordance with claim 4 in which the body of the semiconductor material is brought into contact with the second surface of the solution.
Claim 5
Dependent Claim
33 words
The method in accordance with claim 4 in which the body of the semiconductor material is placed between the solution and the weight so as to contact the first surface of the solution.
Claim 6
Dependent Claim
109 words
The method in accordance with claim 3 in which a plurality of epitaxial layers of a semiconductor material are deposited in succession on the substrate by providing in a plurality of separate confined spaces separate solutions of the semiconductor material in a molten solvent, placing a separate weight on each of said solutions to spread the solution as a thin layer over the entire bottom surface of its respective confined space, bringing the substrate into each of the solutions in succession, and while the substrate is in each of said solutions cooling the solution to deposit an epitaxial layer of the semiconductor material from said solution on saId substrate.
Claim 7
Dependent Claim
52 words
The method in accordance with claim 7 in which prior to bringing the substrate into each of the solutions a body of the semiconductor material is brought into contact with the solution so as to exactly saturate the solution, and then the substrate is brought into contact with the exactly saturated solution.
Claim 8
Dependent Claim
41 words
The method in accordance with claim 8 in which a single body of the semiconductor material is brought into contact with the second surface of each of the solutions in succession just prior to bringing the substrate into the respective solutions.
Claim 9
Dependent Claim
38 words
The method in accordance with claim 8 in which a separate body of the semiconductor material is placed between each of the solutions and its respective weight so as to contact the first surface of its respective solution.
Claim 10
Dependent Claim
41 words
The method in accordance with claim 10 in which each of the bodies of the semiconductor material and its respective weight are brought into contact with their respective solutions in succession just prior to bringing the substrate into the respective solutions.
Claim 11
Independent Claim
228 words
A method of depositing on a substrate a plurality of epitaxial layers of a semiconductor material in succession using a furnace boat having a plurality of spaced wells in a surface thereof and a substrate carrier slide extending through the boat and across the bottoms of the wells so that a surface of the slide forms the bottoms of the wells comprising the steps of: a. providing in each of at least two of said wells a separate solution of a semiconductor material dissolved in a molten metal solvent, each of said solutions being of a sufficiently small volume that the surface tension of the materials of the solution is large enough to prevent the solution from spreading out over the entire bottom surface of its respective well, b. providing in each of the wells which contains a solution a weight which applies a force on the solution and spreads the solution over the entire bottom surface of the well as a thin layer, c. providing a substrate in a recess in said surface of said substrate carrier slide, d. moving said slide so as to bring said substrate into each of said wells in succession, and e. while the substrate is in each of said wells cooling the solution in said well to deposit an epitaxial layer of the semiconductor material from said solution on said substrate.
Claim 12
Dependent Claim
49 words
The method in accordance with claim 12 in which prior to bringing the substrate into a well a body of the semiconductor material in the solution is brought into contact with the solution so as to exactly saturate the solution, and then the substrate is brought into the well.
Claim 13
Dependent Claim
55 words
The method in accordance with claim 13 in which the body of the semiconductor material is in a recess in said surface of the substrate carrier slide so that the body is moved into each well prior to the substrate and is moved out of the well when the substrate is moved into the well.
Claim 14
Dependent Claim
29 words
The method in accordance with claim 13 in which a separate body of the semiconductor material is provided in each of the wells between the solution and the weight.
Claim 15
Dependent Claim
80 words
The method in accordance with claim 15 including a second slide extending through the boat and across the wells spaced from the substrate carrier slide, each body of the semiconductor material and its respective weight are mounted on the second slide and are brought into contact with the respective solution prior to moving the substrate into the well by moving the second slide from across the respective well and allowing the body and the weight to drop onto the solution.
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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |