US3768151A
Expired / Lapsed
US
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Method of forming ohmic contacts to semiconductors
Assignee: International Business Machines Corp
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Filing: 1970-11-03
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Granted: 1973-10-30
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Expires: 1990-11-03
Abstract
Abstract Injection lasers are formed from an n type gallium arsenide wafer. A layer of tungsten is deposited on one surface of the wafer. Zinc is diffused from within or through the layer of tungsten to form a junction and an ohmic contact between the zinc diffused region and the tungsten layer. The tungsten itself does not liquify. Nor is there liquification of the combination of the tungsten, gallium arsenide and zinc during the diffusion. The wafer is lapped, ohmic contact is made to the opposite surface, indium is electroplated on the tungsten, and the individual injection laser diodes are cleaved out of the wafer.
Inventors
- 👤 J Marinace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:31
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/80; H10H20/83; H10H20/832; H10D; H10D62/00; H10D62/80; H10D62/85; H10D64/00; H10D64/01; H10D64/011; H10D64/0116; H10D64/60; H10D64/62; H10P; H10P32/00; H10P32/10; H10P32/14; H10P32/17; H10P32/174; H10W; H10W20/00; H10W20/40; H10H20/81; H10H20/822; H10H20/824; Y; Y10; Y10S; Y10S148/00; Y10S148/02; Y10S148/056; Y10S148/106; Y10S148/157; Y10S438/00; Y10S438/914; Y10S438/923
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
25 words
The method as set forth in claim 1 wherein the step of diffusing impurity atoms comprises diffusing impurity atoms through said layer of conductive material.
Claim 2
Dependent Claim
26 words
The method as set forth in claim 1 wherein the step of diffusing an impurity comprises diffusing said impurity from within said layer of conductive material.
Claim 3
Dependent Claim
57 words
The method as set forth in claim 1 wherein said layer of conductive material exhibits a pattern formed by the steps of laying down an insulating layer on said surface and etching said pattern through said insulating layer on said surface to form said pattern for thereby defining and forming the pattern desired for said conductive material.
Claim 4
Dependent Claim
19 words
The method as set forth in claim 4 wherein said layer of conductive material is electroplated on said surface.
Claim 5
Dependent Claim
26 words
The method as set forth in claim 4 wherein said layer of conductive material is sputtered onto said surface simultaneously with the sputtering of said impurity.
Claim 6
Dependent Claim
28 words
The method as set forth in claim 1 wherein said layer of conductive material is selected from the group consisting of tungsten, molybdenum, chromium, manganese, rhodium, and cobalt-tungsten.
Claim 7
Dependent Claim
50 words
The method as set forth in claim 1 wherein the said at least one portion of said body into which said impurity atoms of one conductivity determining type are diffused is originally doped to be of opposite conductivity type thereto and said diffusion produces a p-n junction in said body.
Claim 8
Dependent Claim
19 words
The method as set forth in claim 8 wherein said semiconductor material is gallium-arsenide, and said impurity is zinc.
Claim 9
Dependent Claim
16 words
The method as set forth in claim 9 wherein said layer of conductive material is tungsten.
Claim 10
Dependent Claim
16 words
The method as set forth in claim 9 wherein said layer of conductive material is molybdenum.
Claim 11
Dependent Claim
16 words
The method as set forth in claim 9 wherein said layer of conductive material is chromium.
Claim 12
Dependent Claim
16 words
The method as set forth in claim 9 wherein said layer of conductive material is rhodium.
Claim 13
Dependent Claim
16 words
The method as set forth in claim 9 wherein said layer of conductive material is cobalt-tungsten.
Claim 14
Dependent Claim
16 words
The method as set forth in claim 9 wherein said layer of conductive material is manganese.
Claim 15
Independent Claim
164 words
A method of making an ohmic contact to a body of semiconductor material and at the same time forming a junction in said body, comprising the steps of: providing on at least one portion of one surface of the body a layer of conductive material selected from the group consisting of tungsten, molybdenum, chromium, manganese, rhodium and cobalt-tungsten; diffusing into the said at least one portion of one surface of the body impurity atoms different than those of said conductive material of one conductivity determining type without exceeding the temperature at which said conductive material reacts with said semiconductor material or liquifies either by itself or in contact with said semiconductor materials; and controlling the time and temperature of said diffusion to thereby form in said body a region adjacent to said surface doped with said impurity atoms of one conductivity determining type which is ohmically connected to said layer of conductive material and which forms a junction with the remainder of said body.
Claim 16
Dependent Claim
25 words
The method as set forth in claim 16 wherein the step of diffusing impurity atoms comprises diffusing impurity atoms through said layer of conductive material.
Claim 17
Dependent Claim
26 words
The method as set forth in claim 16 wherein the step of diffusing an impurity comprises diffusing an impurity from within said layer of conductive material.
Claim 18
Independent Claim
230 words
A method of fabricating a junction in a body of semiconductor material and at the same time making ohmic contact to a region of one conductivity type on one side of said junction, comprising the steps of: providing a body of semiconductor material having at least a first region having one surface extending to one surface of said body which region is doped to be of opposite conductivity type to said one conductivity type; forming on at least a portion of said one surface of said first region a layer of conductive material which does not substantially impede the diffusion of impurity atoms different than those of said conductive material which form said one conductivity type; diffusing into the said at least a portion of said one surface of said first region said impurity atoms so as to form a diffused region therein of said one conductivity type without exceeding the temperature at which said conductive material reacts with said semiconducTor material or liquifies either by itself or in contact with said semiconductor materials; and controlling the time and temperature of said diffusion to both form a p-n junction in said semiconductor body at least between said diffused region of one conductivity type and said first region and at the same time form an ohmic contact between said diffused region of one conductivity type and said layer of conductive material.
Claim 19
Dependent Claim
39 words
The method as set forth in claim 19 wherein the time and temperature of said diffusion is controlled to form said p-n junction at a distance from said one surface which is equal to or less than 5 microns.
Claim 20
Dependent Claim
31 words
The method as set forth in claim 20 wherein said body of semiconductive material is a body of gallium arsenide, said first region is n-type, and said particular impurity is zinc.
Claim 21
Dependent Claim
28 words
The method as set forth in claim 21 wherein said layer of conductive material is selected from the group consisting of tungsten, molybdenum, chromium, manganese, rhodium and cobalt-tungsten.
Claim 22
Independent Claim
139 words
A method of fabricating an injection laser having a lasing junction near one surface of a semiconductor body whereby lasing is produced along that junction, comprising the steps of: providing a body of gallium arsenide including at least a first region extending to said one surface which is doped to be n type; forming on at least a portion of said one surface adjacent said first region a layer of tungsten; and diffusing zinc atoms into the said at least a portion of said one surface adjacent said first region to form a p-type region in said first n-type region and a p-n junction therebetween; said diffusion being carried out below the temperature at which said tungsten liquifies or reacts with said gallium arsenide and producing an ohmic connection between said layer of tungsten and said diffused p-type region.
Claim 23
Dependent Claim
40 words
The method of claim 23 wherein the time and temperature of said diffusion is controlled relative to the thickness of said layer of tungsten to form said p-n junction at a distance less than 25 microns from said one surface.
Claim 24
Dependent Claim
27 words
The method of claim 24 wherein said p-n junction is formed at a distance from said one surface which is equal to or less than 5 microns.
Claim 25
Dependent Claim
17 words
The method of claim 25 wherein the thickness of said layer of tungsten is about 3,000 angstroms.
Claim 26
Dependent Claim
16 words
The method of claim 26 wherein the temperature of said diffusion does not exceed 850* C.
Claim 27
Dependent Claim
17 words
The method of claim 23 wherein the step of diffusing comprises diffusing through said layer of tungsten.
Claim 28
Dependent Claim
18 words
The method of claim 23 wherein the step of diffusing comprises diffusing from within said layer of tungsten.
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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |