Patent US4588455A successfully refreshed from Google Patents.
US4588455A
Expired / Lapsed
US
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Planar diffusion source
Assignee: EMULSITONE COMPANY A CORP OF NJ
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Filing: 1984-08-15
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Granted: 1986-05-13
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Expires: 2004-08-15
Abstract
Abstract Planar diffusion sources are provided wherein the source is a wafer of inert material, preferably silicon or silicon dioxide and wherein the wafer acts as a substrate for a surface coating comprising a salt, preferably the oxide, of the dopant element. An inert oxide such as aluminum oxide or silicon dioxide may also be included in the coating. When applied to the substrate as a paste or slurry and fired to suitable temperatures, the dopant oxide coating tightly adheres to the substrate wafer. The coated diffusion source is placed alongside semi-conductor wafers in a diffusion furnace; where, at diffusion temperatures, the dopant element volatilizes and diffuses into the surface of the semi-conductor material. The diffusion source can be reused numerous times.
Inventors
- 👤 Milton Genser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:56
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/19; H10P32/12; H10P32/17; H10P32/171; Y; Y10; Y10S; Y10S148/00; Y10S148/03; Y10S252/00; Y10S252/95; Y10S252/951
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
76 words
A method for effecting the doping of semi-conductor materials comprising coating an inert solid substrate with a solid layer of a composition including an inorganic salt of the dopant element, placing said coated substrate in close proximity to a semi-conductor material to be doped, heating both said coated substrate and semi-conductor material to a temperature sufficiently high to volatilize the dopant element, whereby said dopant migrates to said semi-conductor material and diffuses into said semi-conductor material.
Claim 2
Independent Claim
76 words
A method for effecting the doping of semi-conductor materials comprising coating an inert solid substrate with a solid layer of a composition including an inorganic salt of the dopant element, placing said coated substrate in close proximity to a semi-conductor material to be doped, heating both said coated substrate and semi-conductor material to a temperature sufficiently high to volatilize the dopant element, whereby said dopant migrates to said semi-conductor material and diffuses into said semi-conductor material.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein the substrate is silicon or silicon dioxide.
Claim 4
Dependent Claim
16 words
The method of claim 1 wherein the inorganic salt of the dopant element is an oxide.
Claim 5
Independent Claim
25 words
The method of claim wherein the oxide is selected from boron oxide, arsenic oxide, antimony oxide, phosphorous oxide, zinc oxide, gallium oxide, or indium oxide.
Claim 6
Dependent Claim
21 words
The method of claim 3 wherein an amount of aluminum oxide is admixed with the inorganic salt of the dopant element.
Claim 7
Dependent Claim
21 words
The method of claim 3 wherein an amount of silicon oxide is admixed with the inorganic salt of the dopant element.
Claim 8
Dependent Claim
21 words
The method of claim 1 wherein said coating is applied to the substrate in the form of a paste or slurry.
Claim 9
Dependent Claim
17 words
The method of claim 7 wherein said paste or slurry includes alcohol, water and a binder material.
Claim 10
Dependent Claim
13 words
The method of claim 8 wherein the binder material is an organic thickener.
Claim 11
Dependent Claim
15 words
The method of claim 9 wherein the organic thickener is a polysaccharide or polysaccharide salt.
Claim 12
Dependent Claim
29 words
The method of claim 1 wherein the substrate and the dopant coating therein is heated to densify the coating and cause the coating to tightly adhere to the substrate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-12 | 1989-11-11 | 1990-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-12 | 1993-11-11 | 1994-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-12 | 1997-11-11 | 1998-05-13 | $7700.00 | Window Closed / Lapsed |