US3634151A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making semiconductor devices
Assignee: Panasonic Holdings Corp
•
Filing: 1970-05-01
•
Granted: 1972-01-11
•
Expires: 1990-05-01
Abstract
Abstract A method is provided for making a PN-junction semiconductor. A crystalline semiconductor wafer having a metal dot placed upwardly thereon is heated to cause the dot to adhere to the wafer. The wafer is then turned upside down at room temperature. The wafer is then heated at a temperature higher than the adhering temperature to cause the dot to interact with the wafer to form a hyperabrupt junction silicon diode.
Inventors
- 👤 Tomi Sato
- 👤 Keiji Matsumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:40
CPC Classifications
H; H10; H10D; H10D99/00; H10D64/00; H10D64/20; H10D64/23; H10P; H10P95/00; H10P95/50; H10W; H10W72/00; H10W72/90
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
25 words
The method defined by claim 1 wherein said wafer having said metal dot adhered to one surface thereof is turned upside down at room temperature.
Claim 2
Dependent Claim
16 words
The method defined by claim 1 wherein said metal dot contains aluminum as an active constituent.
Claim 3
Dependent Claim
35 words
The method defined by claim 1 wherein said crystalline semiconductor wafer having a metal dot placed upwardly on one surface thereof is heated in a reduced pressure lower than 5 X 10 5 mm. Hg.
Claim 4
Dependent Claim
29 words
The method defined by claim 1 wherein said crystalline semiconductor wafer is a member selected from the group consisting of a germanium single crystal and a silicon single crystal.
Claim 5
Dependent Claim
23 words
The method defined by claim 5 wherein said metal dot consists of a metal selected from the group consisting of aluminum and indium.
Claim 6
Dependent Claim
50 words
The method defined by claim 5 wherein said metal dot comprises at least one carrier metal selected from the group consisting of tin, lead, gold, silver and their alloy and at least one active material selected from the group consisting of phosphor, arsenic, antimony, bismuth, boron, aluminum, gallium and indium.
Claim 7
Independent Claim
126 words
A method for making a silicon diode provided with hyperabrupt PN-junction, said method comprising heating a P-type silicon wafer having an alloy dot placed upwardly on one surface thereof at a temperature of 540* C. to 940* C. in a reduced pressure of air lower than 5 X 10 5 mm. Hg, whereby said alloy dot melts and adheres to said one surface, said alloy dot including tin, antimony and aluminum; turning said wafer upside down at room temperature so that said adhered alloy dot is placed downwardly on said one surface; further heating said turned wafer at a temperature of 960* C. to 1,080* C. in hydrogen gas for a time period of 5 to 40 minutes; and cooling said turned wafer to room temperature.
References Cited (Backward Citations)
US3544395A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |