US4075038A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Deep diode devices and method and apparatus
Assignee: General Electric Co
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Filing: 1975-02-24
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Granted: 1978-02-21
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Expires: 1995-02-24
Abstract
Abstract Deep diodes which extend in straight lines through a silicon wafer are produced by migrating aluminum droplets through the wafer while maintaining a finite temperature gradient through the wafer in the direction of straight line droplet travel, and at the same time maintaining a zero temperature gradient through the wafer in a direction normal to the droplet travel course. Unidirectional heat flow apparatus implementing this method is also disclosed.
Inventors
- 👤 Thomas R. Anthony
- 👤 Harvey E. Cline
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:37
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/50; H10P10/00; H10P10/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
260 words
The method of making a semiconductor device comprising a body of semiconductive material having a first type conductivity in the form of a wafer having substantially planar top and bottom surfaces and a plurality of separate spaced recrystallized regions of semiconductive material having a second type conductivity extending in straight lines from the top surface to the bottom surface of the body, which comprises the steps of providing in contact with one of said surfaces of the body a plurality of separate deposits of a solid metallic material with which the semiconductive material of the body will form a solution of melting point temperature below that of the semiconductive material of the body, heating the solid metallic material to a predetermined elevated temperature and forming a liquid solution of the semiconductive material of the body at each of the deposit sites, establishing and maintaining a selected finite temperature gradient in a direction normal to the said top and bottom surfaces through the body, and coextensively in time establishing and maintaining a zero temperature gradient through the body in a direction normal to the direction of the said selected finite temperature gradient, and migrating the resulting liquid solution bodies through the body in straight lines from one planar surface to the other and thereby forming in situ separate spaced recrystallized regions having a second type conductivity and having a constant uniform level of impurity concentration throughout their lengths as determined by the solid solubility limit of the metallic material in the semiconductive material of the body at the said predetermined temperature.
Claim 2
Independent Claim
260 words
The method of making a semiconductor device comprising a body of semiconductive material having a first type conductivity in the form of a wafer having substantially planar top and bottom surfaces and a plurality of separate spaced recrystallized regions of semiconductive material having a second type conductivity extending in straight lines from the top surface to the bottom surface of the body, which comprises the steps of providing in contact with one of said surfaces of the body a plurality of separate deposits of a solid metallic material with which the semiconductive material of the body will form a solution of melting point temperature below that of the semiconductive material of the body, heating the solid metallic material to a predetermined elevated temperature and forming a liquid solution of the semiconductive material of the body at each of the deposit sites, establishing and maintaining a selected finite temperature gradient in a direction normal to the said top and bottom surfaces through the body, and coextensively in time establishing and maintaining a zero temperature gradient through the body in a direction normal to the direction of the said selected finite temperature gradient, and migrating the resulting liquid solution bodies through the body in straight lines from one planar surface to the other and thereby forming in situ separate spaced recrystallized regions having a second type conductivity and having a constant uniform level of impurity concentration throughout their lengths as determined by the solid solubility limit of the metallic material in the semiconductive material of the body at the said predetermined temperature.
Claim 3
Dependent Claim
17 words
The method of claim 1 in which the body of semiconductive material is about 10 mils thick.
Claim 4
Dependent Claim
35 words
The method of claim 1 in which the zero temperature gradient is established and maintained by preventing heat flow to or from the body of semiconductive material in a direction normal to the first direction.
Claim 5
Dependent Claim
20 words
The method of claim 1 in which the body of semiconductive material is silicon and the second material is aluminum.
Claim 6
Dependent Claim
21 words
The method of claim 1 in which the body of semiconductive material is N-type silicon and the second material is aluminum.
Claim 7
Dependent Claim
55 words
The method of claim 2 in which the body of semiconductive material is a wafer having recesses in its lower side filled with the second material, and in which heat is delivered to the upper side and is removed from the lower side of the wafer to maintain the temperature gradient vertically within the wafer.
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) | 1981-02-20 | 1981-08-22 | 1982-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-20 | 1985-08-22 | 1986-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-20 | 1989-08-22 | 1990-02-21 | $7700.00 | Window Closed / Lapsed |