Patent US3914138A successfully refreshed from Google Patents.
US3914138A
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US
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Method of making semiconductor devices by single step diffusion
Assignee: Westinghouse Electric Corp
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Filing: 1974-08-16
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Granted: 1975-10-21
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Expires: 1994-08-16
Abstract
Abstract A method of making a semiconductor device by first placing organic volatizable films carrying impurity diffusion material, preferably including aluminum oxide, in contact with the opposed major surfaces of at least one doped semiconductor body; and positioning the assembly in an open-tube diffusion furnace with films contacting the opposed major surfaces of the body alternately carrying N-type and P-type impurity diffusion material. The diffusion furnace is then heated to at least about 1,000*C. and preferably to at least 1,100*C. to volatilize the organic films and simultaneously diffuse the N-type and P-type impurities into the respective opposed major surfaces of the semiconductor body to form at least one PN junction therein. The semiconductor body is then preferably additionally heated to a temperature higher than about 1250*C., preferably in a nitrogen ambient, to drive the impurities into the semiconductor body and also preferably diffuse aluminum from the aluminum oxide into P impurity regions of the semiconductor body. The semiconductor body is thereafter cooled from the diffusion temperature to a temperature between about 550* and 880*C. and preferably between about 575* and 675*C at a rate less than about 3*C. per minute and preferably less than about 2*C. per minute, and thereafter cooled from said temperature to below 300*C. at a rate greater than about 25*C. per minute.
Inventors
- 👤 Prosenjit Rai-Choudhury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:27
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/69; H10P14/692; H10P14/6938; H10P14/6939; H10P14/69391; H10D; H10D99/00; H10P14/65; H10P14/6516; H10P14/6529; H10P14/68; H10P14/683; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/141; H10P32/17; H10P32/171; H10W; H10W74/00; H10W74/40; H10W74/47
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
147 words
A METHOD OF MAKING A SEMICONDUCTOR DEVICE COMPRISING THE STEPS OF: A. CONTACTING VOLATIZABLE ORGANIC FILMS CARRYING IMPURITY DIFFUSION MATERIAL TO OPOSED MAJOR SURFACES OF AT LEAST ONE DOPED SEMICONDUCTOR BODY IN AN OPEN-TUBE DIFFUSION FURNACE, WITH THE FILMS CONTACTING THE OPPOSED MAJJOR SURFACES OF EACH SEMICONDUCTOR BODY ALTERNATELY CARRYING N-TYPE AND P-TYPE IMPURITY DIFFUSION MATERIALS, B. HEATING THE DIFFUSION FURNACE TO A TEMPERATURE HIGHER THAN ABOUT 1,000*C TO VOLATILIZE THE ORGANIC FILMS AND TO DIFFUSE THE N AND P-TYPE IMPURITIES SIMULTANEOUSLY INTO THE RESPECTIVE OPPOSED MAJOR SURFACES OF THE SEMICONDUCTOR BODY TO FORM AT LEAST ONE PN JUNCTION THEREIN, C. SLOWLY COOLING THE SEMICONDUCTOR BODY TO A TWEMPERATURE BETWEEN ABOUT 550* AND 800*C AT A RATE LESS THAN ABOUT 3*C PER MINUTE, AND D. THEREAFTER RAPIDLY COOLING THE SEMICONDUCTOR BODY FROM SAID TEMPERATURE TO BELOW ABOUT 300*C AT A RATE GREATER THAN ABOUT 25*C PER MINUTE.
Claim 2
Independent Claim
147 words
A METHOD OF MAKING A SEMICONDUCTOR DEVICE COMPRISING THE STEPS OF: A. CONTACTING VOLATIZABLE ORGANIC FILMS CARRYING IMPURITY DIFFUSION MATERIAL TO OPOSED MAJOR SURFACES OF AT LEAST ONE DOPED SEMICONDUCTOR BODY IN AN OPEN-TUBE DIFFUSION FURNACE, WITH THE FILMS CONTACTING THE OPPOSED MAJJOR SURFACES OF EACH SEMICONDUCTOR BODY ALTERNATELY CARRYING N-TYPE AND P-TYPE IMPURITY DIFFUSION MATERIALS, B. HEATING THE DIFFUSION FURNACE TO A TEMPERATURE HIGHER THAN ABOUT 1,000*C TO VOLATILIZE THE ORGANIC FILMS AND TO DIFFUSE THE N AND P-TYPE IMPURITIES SIMULTANEOUSLY INTO THE RESPECTIVE OPPOSED MAJOR SURFACES OF THE SEMICONDUCTOR BODY TO FORM AT LEAST ONE PN JUNCTION THEREIN, C. SLOWLY COOLING THE SEMICONDUCTOR BODY TO A TWEMPERATURE BETWEEN ABOUT 550* AND 800*C AT A RATE LESS THAN ABOUT 3*C PER MINUTE, AND D. THEREAFTER RAPIDLY COOLING THE SEMICONDUCTOR BODY FROM SAID TEMPERATURE TO BELOW ABOUT 300*C AT A RATE GREATER THAN ABOUT 25*C PER MINUTE.
Claim 3
Dependent Claim
31 words
The method of making a semiconductor device as set forth in claim 1 wherein: in step B, the heating of the diffusion furnace is to a temperature higher than about 1,100*C.
Claim 4
Dependent Claim
48 words
The method of making a semiconductor device as set forth in claim 1 comprising in addition between the heating and slow cooling steps: additionally heating the semiconductor body in a diffusion furnace to a temperature of at least about 1,250*C to drive the impurities into the semiconductor body.
Claim 5
Dependent Claim
36 words
A method of making a semiconductor device as set forth in claim 1 wherein: said volatizable organic films in contact with the opposed major surfaces of each semiconductor body alternately carry phosphorus and boron diffUsion materials.
Claim 6
Dependent Claim
37 words
A method of making a semiconductor device as set forth in claim 4 wherein: said volatizable organic films in contact with the opposed major surfaces of each semiconductor body alternately carry ammonium dihydrogen phosphate and boron nitride.
Claim 7
Dependent Claim
26 words
A method of making a semiconductor device as set forth in claim 4 where in addition: each said volatizable organic film in addition carries aluminum oxide.
Claim 8
Dependent Claim
68 words
A method of making a semiconductor device as set forth in claim 6 comprising in addition between the heating and slow cooling steps: additionally heating the semiconductor body in a diffusion furnace to a temperature of at least about 1,250*C, while maintaining a nitrogen atmosphere in the diffusion furnace, to drive the impurities into the semiconductor body and diffuse aluminum into P-type impurity regions of the semiconductor body.
Claim 9
Dependent Claim
38 words
The method of making a semiconductor device as set forth in claim 1 wherein: in step C, the slow cooling is to a temperature between about 575* and 675*C at a rate less than about 2*C per minute.
Claim 10
Dependent Claim
36 words
A method of making a semiconductor device as set forth in claim 8 wherein: said volatizable organic films in contact with the opposed major surfaces of each semiconductor body alternately carry phosphorus and boron diffusion materials.
Claim 11
Dependent Claim
47 words
A method of making a semiconductor device with a high voltage PN junction by single step diffusion as set forth in claim 9 wherein: said volatizable organic films in contact with the opposed major surfaces of each semiconductor body alternately carry ammonium dihydrogen phosphate and boron nitride.
Claim 12
Dependent Claim
26 words
A method of making a semiconductor device as set forth in claim 9 where in addition: each said volatizable organic film in addition carries aluminum oxide.
Claim 13
Dependent Claim
68 words
A method of making a semiconductor device as set forth in claim 11 comprising in addition between the heating and slow cooling steps: additionally heating the semiconductor body in a diffusion furnace to a temperature of at least about 1,250*C, while maintaining a nitrogen atmosphere in the diffusion furnace, to drive the impurities into the semiconductor body and diffuse aluminum into P-type impurity regions of the semiconductor body.
Claim 14
Independent Claim
152 words
A method of making a semiconductor device utilizing Czochralski silicon comprising the steps of: A. contacting volatizable organic films carrying impurity diffusion material to opposed major surfaces of at leat one doped semiconductor body of Czochralski silicon in an open-tube diffusion furnace, with the films contacting the opposed major surfaces of each semiconductor body alternately carrying N-type and P-type impurity diffusion materials; B. heating the diffusion furnace to a temperature higher than about 1,000*C to volatilize the organic films and diffuse the N and P-type impurities simultaneously into the respective opposed major surfaces of each semiconductor body to form at least one PN junction therein; C. slowly cooling the semiconductor body to a temperature between about 550* and 800*C at a rate less than about 3*C per minute; and D. thereafter rapidly cooling the semiconductor body from said temperature to below about 300*C at a rate greater than about 25*C per minute.
Claim 15
Independent Claim
152 words
A method of making a semiconductor device utilizing Czochralski silicon comprising the steps of: A. contacting volatizable organic films carrying impurity diffusion material to opposed major surfaces of at leat one doped semiconductor body of Czochralski silicon in an open-tube diffusion furnace, with the films contacting the opposed major surfaces of each semiconductor body alternately carrying N-type and P-type impurity diffusion materials; B. heating the diffusion furnace to a temperature higher than about 1,000*C to volatilize the organic films and diffuse the N and P-type impurities simultaneously into the respective opposed major surfaces of each semiconductor body to form at least one PN junction therein; C. slowly cooling the semiconductor body to a temperature between about 550* and 800*C at a rate less than about 3*C per minute; and D. thereafter rapidly cooling the semiconductor body from said temperature to below about 300*C at a rate greater than about 25*C per minute.
Claim 16
Dependent Claim
32 words
The method of making a semiconductor device as set forth in claim 13 wherein: in step B the heating of the diffusion furnace is carried to a temperature higher than about 1,100*C.
Claim 17
Dependent Claim
52 words
The method of making a semiconductor device utilizing Czochralski silicon as set forth in in claim 13 comprising in addition between the heating and slow cooling steps: additionally heating the semiconductor body in a diffusion furnace to a temperature of at least about 1,250*C to drive the impurities into the semiconductor body.
Claim 18
Dependent Claim
39 words
A method of making a semiconductoR device utilizing Czochralski silicon as set forth in claim 13 wherein: said volatizable organic films in contact with the opposed major surfaces of each semiconductor body alternately carry phosphorus and boron diffusion materials.
Claim 19
Dependent Claim
40 words
A method of making a semiconductor device utilizing Czochralski silicon as set forth in claim 16 wherein: said volatizable organic films in contact with the opposed major surfaces of each semiconductor body alternately carry ammonium dihydrogen phosphate and boron nitride.
Claim 20
Dependent Claim
28 words
A method of making a semiconductor device utilizing Czochralski silicon as set forth in claim 16 where in addition: each said organic film in addition carries aluminum oxide.
Claim 21
Dependent Claim
71 words
A method of making a semiconductor device utilizing Czochralski silicon as set forth in claim 18 comprising in addition between the heating and slow cooling steps: additionally heating the semiconductor body in a diffusion furnace to a temperature of at least about 1,250*C, while maintaining a nitrogen atmosphere in the diffusion furnace, to drive the impurities into the semiconductor body and diffuse aluminum into P-type impurity regions of the semiconductor body.
Claim 22
Dependent Claim
41 words
The method of making a semiconductor device utilizing Czochralski silicon as set forth in claim 13 wherein: in Step C, the slow cooling is to a temperature between about 575* and 675*C at a rate less than about 2*C per minute.
Claim 23
Dependent Claim
39 words
A method of making a semiconductor device utilizing Czochralski silicon as set forth in claim 20 wherein: said volatizable organic films in contact with the opposed major surfaces of each semiconductor body alternately carry phosphorus and boron diffusion materials.
Claim 24
Dependent Claim
40 words
A method of making a semiconductor device utilizing Czochralski silicon as set forth in claim 21 wherein: said volatizable organic films in contact with the opposed major surfaces of each semiconductor body alternately carry ammonium dihydrogen phosphate and boron nitride.
Claim 25
Dependent Claim
28 words
A method of making a semiconductor device utilizing Czochralski silicon as set forth in claim 21 where in addition: each said organic film in addition carries aluminum oxide.
Claim 26
Dependent Claim
70 words
A method of making a semiconductor device utilizing Czochralski silicon as set forth in claim 23 comprising in addition between the heating and cooling steps: additionally heating the semiconductor body in a diffusion furnace to a temperature of at least about 1,250*C, while maintaining a nitrogen atmosphere in the diffusion furnace, to drive the impurities into the semiconductor body and diffuse aluminum into P-type impurity regions of the semiconductor body.
Claim 27
Independent Claim
108 words
A method of making a semiconductor device comprising the steps of: A. contacting a volatizable organic film carrying at least one impurity diffusion material to a major surface of at least one semiconductor body; B. heating the diffusion furnace to a temperature higher than about 1,000*C to volatilize the organic film and to diffuse impurities into the major surface of the semiconductor body; C. cooling the semiconductor body to a temperature between about 550* and 800*C at a rate less than about 3*C per minute; and D. thereafter cooling the semiconductor body from said temperature to below about 300*C at a rate greater than about 25*C per minute.
Claim 28
Independent Claim
108 words
A method of making a semiconductor device comprising the steps of: A. contacting a volatizable organic film carrying at least one impurity diffusion material to a major surface of at least one semiconductor body; B. heating the diffusion furnace to a temperature higher than about 1,000*C to volatilize the organic film and to diffuse impurities into the major surface of the semiconductor body; C. cooling the semiconductor body to a temperature between about 550* and 800*C at a rate less than about 3*C per minute; and D. thereafter cooling the semiconductor body from said temperature to below about 300*C at a rate greater than about 25*C per minute.
Claim 29
Dependent Claim
31 words
The method of making a semiconductor device as set forth in claim 25 wherein: in Step B, the heating of the diffusion furnace is to a temperature higher than about 1,100*C.
Claim 30
Dependent Claim
87 words
A method of making a semiconductor device as set forth in claim 25 wherein: the organic film carries aluminum oxide and at least one other P-type impurity diffusion material; and comprising the additional step between the heating and slow cooling steps: additionally heating the semiconductor body in a diffusion furnace to a temperAture of at least about 1,250*C, while maintaining a nitrogen atmosphere in the diffusion furnace, to drive the P-type impurities into the semiconductor body and diffuse aluminum into P-type impurity regions of the semiconductor body.
Claim 31
Dependent Claim
30 words
A method of making a semiconductor device as set forth in claim 26 wherein: in Step C, the slow cooling is carried to a temperature between about 575* and 675*C.
Claim 32
Independent Claim
99 words
A method of making a semiconductor device utilizing Czochralski silicon comprising the steps of: A. placing at least one doped semiconductor body of Czochralski silicon in a diffusion furnace; B. heating the diffusion furnace to a temperature higher than about 1,000*C and diffusing an impurity into the semiconductor body to form a PN junction therein; C. cooling the semiconductor body to a temperature between 550* and 800*C at a rate less than about 3*C per minute; and D. thereafter cooling the semiconductor body from said temperature to below about 300*C at a rate greater than about 25*C per minute.
Claim 33
Independent Claim
99 words
A method of making a semiconductor device utilizing Czochralski silicon comprising the steps of: A. placing at least one doped semiconductor body of Czochralski silicon in a diffusion furnace; B. heating the diffusion furnace to a temperature higher than about 1,000*C and diffusing an impurity into the semiconductor body to form a PN junction therein; C. cooling the semiconductor body to a temperature between 550* and 800*C at a rate less than about 3*C per minute; and D. thereafter cooling the semiconductor body from said temperature to below about 300*C at a rate greater than about 25*C per minute.
Claim 34
Dependent Claim
34 words
A method of making a semiconductor device utilizing Czochralski silicon as set forth in claim 29 wherein: in Step B, the heating of the diffusion furnace is to a temperature higher than about 1,100*C.
Claim 35
Dependent Claim
33 words
A method of making a semiconductor device utilizing Czochralski silicon as set forth in claim 29 wherein: in Step C, the slow cooling is at a rate less than about 2*C per minute.
Claim 36
Dependent Claim
32 words
A method of making a semiconductor device utilizing Czochralski silicon as set forth in claim 29 wherein: in Step C, the slow cooling is to a temperature between about 575* and 675*C.
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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) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |