US3619288A
Expired / Lapsed
US
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Process for precipitating a high melting metal contact layer at low temperatures
Assignee: Siemens AG
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Filing: 1969-12-22
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Granted: 1971-11-09
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Expires: 1989-12-22
Abstract
Abstract A method for precipitating a high melting metal contact layer, at low temperatures, through thermal dissociation of a gaseous compound of the high melting contact metal and precipitating the same upon a carrier body, preferably of semiconductor material. The metal contact layer is precipitated upon the carrier body through thermal dissociation of the easily volatile trifluorophosphine or trifluorophosphine hydride of the respective metals.
Inventors
- 👤 Erhard Sirtl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:35
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/02; C23C16/0227; C23C16/0236; C23C16/06
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
12 words
The method of claim 1, wherein a semiconductor is the carrier body.
Claim 2
Dependent Claim
30 words
The method of claim 2, wherein trifluorophosphine compounds of a metal selected from nickel, cobalt, iron, chromium, molybdenum, tungsten, niobium, tantalum, vanadium and metals of the platinum group, is used.
Claim 3
Dependent Claim
33 words
The method of claim 3, wherein the carrier surface is subjected, prior to precipitation of the contact metal layer, to a pretreatment of sulphur hexafluoride (SF6) or nitrogen trifluoride (NF3) at elevated temperatures.
Claim 4
Dependent Claim
15 words
The method of claim 3, wherein the temperature range is between 500* and 1,000* C.
Claim 5
Dependent Claim
24 words
The method of claim 1, wherein hydrogen or a noble gas is used as a carrier gas during the thermal dissociation of trifluorophosphine compounds.
Claim 6
Dependent Claim
25 words
The method of claim 6, wherein the thermal dissociation is effected at reduced pressure, preferably in a dynamic vacuum of 10 3 to 1 Torr.
Claim 7
Dependent Claim
15 words
The method of claim 7 wherein the pressure is reduced 10 3 to 1 Torr.
Claim 8
Dependent Claim
29 words
The method of claim 1, wherein the carrier body is heated to a temperature required for thermal dissociation, through indirect heating of A quartz table in thermal contact therewith.
Claim 9
Dependent Claim
19 words
The method of claim 9, wherein a slit molybdenum wafer is used as a heater and rinsed with argon.
Claim 10
Dependent Claim
18 words
The method of claim 1, wherein the thermal dissociation is at a temperature of 350* to 600* C.
Claim 11
Dependent Claim
29 words
The method of claim 1, wherein a selective precipitation of the contact metal layer upon the carrier surface is produced by an energy source which acts from the outside.
Claim 12
Dependent Claim
16 words
The method of claim 1, wherein the carrier body is selected from quartz, ceramic or metal.
Claim 13
Dependent Claim
17 words
The method of claim 6, wherein the trifluorophosphine compound is vaporized at from 20* to 100* C.
Claim 14
Dependent Claim
17 words
The method of claim 1, wherein the contact metal layer is precipitated in thickness of 1000 A.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-08 | 1975-05-10 | 1975-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-08 | 1979-05-10 | 1979-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-08 | 1983-05-10 | 1983-11-09 | $7700.00 | Window Closed / Lapsed |