US3915767A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rapidly responsive transistor with narrowed base
Assignee: Honeywell Inc
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Filing: 1973-02-05
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Granted: 1975-10-28
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Expires: 1993-02-05
Abstract
Abstract Bipolar transistors having a narrowed base under the emitter regions are disclosed for use in fast responding circuits. The narrow base region under the emitter region is obtained during simultaneous diffusion of both regions. Further steps provide a transistor with a small, heavily doped emitter that is conveniently formed in monolithic integrated circuits.
Inventors
- 👤 Lawrence C Welliver
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:07
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/40; H10D62/405; H10D99/00; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10P14/6322; H10P14/66; H10P14/662; H10P14/69; H10P14/692; H10P14/6921; H10P14/69215; H10P14/6922; H10P14/6923; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/1414; H10P32/17; H10P32/171; H10P95/00; H10W; H10W20/00; H10W20/40
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
271 words
A METHOD FOR CONSTRUCTING A SEMICONDUCTOR DEVICE AT AN OUTER MAJOR SURFACE OF A FIRST LAYER OF SEMICONDUCTOR MATERIAL OF A FIRST CONDUCTIVITY TYPE, SAID METHOD COMPRISING: PROVIDING A FIRST DIFFUSANT AT A SELECTED AREA OF SAID OUTER MAJOR SURFACE, SAID FIRST DIFFUSANT BEING OF A KIND TENDING TO CAUSE SAID FIRST LAYER TO BE LOCALLY OF A SECOND CONDUCTIVITY TYPE WHEN DIFFUSED THEREIN, PROVIDING A FIRST INSULATIVE LAYER ON SAID OUTER MAJOR SURFACE WITH AN OPENING IN SAID FIRST INSULATIVE LAYER TO PROVIDE A FIRST EXPOSURE OF A PORTION OF SAID SELECTED AREA, PROVIDING A SECOND DIFFUSANT AT SAID OPENING WITH I) SAID SECOND DIFFUSANT BEING OF A KIND TENDING TO CAUSE SAID FIRST LAYER TO BE LOCALLY OF SAID CONDUCTIVITY TYPE WHEN DIFFUSED THEREIN, (II) SAID SECOND DIFFUSANT, AS PROVIDED, BEING OF A KIND TO SUBSTANTIALLY DIFFUSE BEHIND SAID FIRST DIFFUSANT, AS PROVIDED, WHEN SIMULTANEOUSLY DIFFUSED THEREWITH INWARDLY INTO SAID FIRST LAYER, AND III) SAID SECOND DIFFUSANT, AS PROVIDED, BEING OF A KIND CAPABLE OF LIMITING PROGRESS OF A DIFFUSION OF SAID FIRST DIFFUSANT, AS PROVIDED, ALONG DIRECTIONS SUBSTANTIALLY PERPENDICULAR TO SAID OUTER MAJOR SURFACE WHERE SAID SECOND DIFFUSANT IS SIMULTANEOUSLY DIFFUSED ALONG SAID DIRECTIONS IN SUFFICIENTLYY CLOSE PROSIMITY TO SAID FIRST DIFFUSANT, RELATIVE TO PROGRESS OF SAID DIFFUSION OF SAID FIRST DIFFUSANT WHERE SAID SECOND DIFFUSANT, IS RELATIVELY REMOTE FROM SAID DIFFUSION OF SAID FIRST DIFFUSANT,AND DIFFUSING SAID FIRST AND SECOND DIFFUSANTS SIMULTANEOUSLY INTO SAID FIRST LAYER WHEREBY A DIFFUSED DEVICE RESULTS HAVING A REGION OF SAID SECOND CONDUCTIVITY TYPE THAT IS SUBSTANTIALLY NARROWED ON EITHER SIDE THEREOF WHERE INTERPOSED BETWEEN TWO REGIONS OF SAID FIRST CONDUCTIVITY TYPE.
Claim 2
Independent Claim
271 words
A METHOD FOR CONSTRUCTING A SEMICONDUCTOR DEVICE AT AN OUTER MAJOR SURFACE OF A FIRST LAYER OF SEMICONDUCTOR MATERIAL OF A FIRST CONDUCTIVITY TYPE, SAID METHOD COMPRISING: PROVIDING A FIRST DIFFUSANT AT A SELECTED AREA OF SAID OUTER MAJOR SURFACE, SAID FIRST DIFFUSANT BEING OF A KIND TENDING TO CAUSE SAID FIRST LAYER TO BE LOCALLY OF A SECOND CONDUCTIVITY TYPE WHEN DIFFUSED THEREIN, PROVIDING A FIRST INSULATIVE LAYER ON SAID OUTER MAJOR SURFACE WITH AN OPENING IN SAID FIRST INSULATIVE LAYER TO PROVIDE A FIRST EXPOSURE OF A PORTION OF SAID SELECTED AREA, PROVIDING A SECOND DIFFUSANT AT SAID OPENING WITH I) SAID SECOND DIFFUSANT BEING OF A KIND TENDING TO CAUSE SAID FIRST LAYER TO BE LOCALLY OF SAID CONDUCTIVITY TYPE WHEN DIFFUSED THEREIN, (II) SAID SECOND DIFFUSANT, AS PROVIDED, BEING OF A KIND TO SUBSTANTIALLY DIFFUSE BEHIND SAID FIRST DIFFUSANT, AS PROVIDED, WHEN SIMULTANEOUSLY DIFFUSED THEREWITH INWARDLY INTO SAID FIRST LAYER, AND III) SAID SECOND DIFFUSANT, AS PROVIDED, BEING OF A KIND CAPABLE OF LIMITING PROGRESS OF A DIFFUSION OF SAID FIRST DIFFUSANT, AS PROVIDED, ALONG DIRECTIONS SUBSTANTIALLY PERPENDICULAR TO SAID OUTER MAJOR SURFACE WHERE SAID SECOND DIFFUSANT IS SIMULTANEOUSLY DIFFUSED ALONG SAID DIRECTIONS IN SUFFICIENTLYY CLOSE PROSIMITY TO SAID FIRST DIFFUSANT, RELATIVE TO PROGRESS OF SAID DIFFUSION OF SAID FIRST DIFFUSANT WHERE SAID SECOND DIFFUSANT, IS RELATIVELY REMOTE FROM SAID DIFFUSION OF SAID FIRST DIFFUSANT,AND DIFFUSING SAID FIRST AND SECOND DIFFUSANTS SIMULTANEOUSLY INTO SAID FIRST LAYER WHEREBY A DIFFUSED DEVICE RESULTS HAVING A REGION OF SAID SECOND CONDUCTIVITY TYPE THAT IS SUBSTANTIALLY NARROWED ON EITHER SIDE THEREOF WHERE INTERPOSED BETWEEN TWO REGIONS OF SAID FIRST CONDUCTIVITY TYPE.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein said outer major surface is oriented in substantially a (100) orientation.
Claim 4
Dependent Claim
32 words
The method of claim 2 wherein said providing of said first diffusant is accomplished by diffusing said first diffusant shallowly into said first layer through said selected area in an initial diffusion.
Claim 5
Dependent Claim
22 words
The method of claim 3 wherein said first diffusant is boron which is diffused substantially uniformly and said first layer is silicon.
Claim 6
Dependent Claim
32 words
The method of claim 1 wherein said providing of said first diffusant is accomplished by diffusing said first diffusant shallowly into said first layer through said selected area in an initial diffusion.
Claim 7
Dependent Claim
16 words
The method of claim 5 wherein said first diffusant is boron which is diffused substantially uniformly.
Claim 8
Independent Claim
295 words
A method for constructing a semiconductor device at an outer major surface of a first layer of semiconductor material of a first conductivity type, said method comprising: providing a first diffusant at a selected area of said outer major surface, said first diffusant being of a kind tending to cause said first layer to be locally of a Second conductivity type when diffused therein; providing a first insulative layer on said outer major surface with an opening in said first insulative layer to provide a first exposure of a portion of said selected area; providing a second diffusant at said opening by depositing doped polysilicon on said major outer surface at said first exposure, said doped polysilicon being doped with said second diffusant, with i) said second diffusant being of a kind tending to cause said first layer to be locally of said first conductivity type when diffused therein, ii) said second diffusant, as provided, being of a kind to substantially diffuse behind said first diffusant, as provided, when simultaneously diffused therewith inwardly into said first layer, and iii) said second diffusant, as provided, being of a kind capable of limiting progress of a diffusion of said first diffusant, as provided, along directions substantially perpendicular to said outer major surface where said second diffusant is simultaneously diffused along said directions in sufficiently close proximity to said first diffusant, relative to progress of said diffusion of said first diffusant where said second diffusant is relatively remote from said diffusion of said first diffusant; and diffusing said first and second diffusants simultaneously into said first layer whereby a diffused device results having a region of said second conductivity type that is substantially narrowed on either side thereof where interposed between two regions of said first conductivity type.
Claim 9
Independent Claim
295 words
A method for constructing a semiconductor device at an outer major surface of a first layer of semiconductor material of a first conductivity type, said method comprising: providing a first diffusant at a selected area of said outer major surface, said first diffusant being of a kind tending to cause said first layer to be locally of a Second conductivity type when diffused therein; providing a first insulative layer on said outer major surface with an opening in said first insulative layer to provide a first exposure of a portion of said selected area; providing a second diffusant at said opening by depositing doped polysilicon on said major outer surface at said first exposure, said doped polysilicon being doped with said second diffusant, with i) said second diffusant being of a kind tending to cause said first layer to be locally of said first conductivity type when diffused therein, ii) said second diffusant, as provided, being of a kind to substantially diffuse behind said first diffusant, as provided, when simultaneously diffused therewith inwardly into said first layer, and iii) said second diffusant, as provided, being of a kind capable of limiting progress of a diffusion of said first diffusant, as provided, along directions substantially perpendicular to said outer major surface where said second diffusant is simultaneously diffused along said directions in sufficiently close proximity to said first diffusant, relative to progress of said diffusion of said first diffusant where said second diffusant is relatively remote from said diffusion of said first diffusant; and diffusing said first and second diffusants simultaneously into said first layer whereby a diffused device results having a region of said second conductivity type that is substantially narrowed on either side thereof where interposed between two regions of said first conductivity type.
Claim 10
Dependent Claim
134 words
The method of claim 7 wherein said diffusing of said first and second diffusants simultaneously is followed by: providing a second insulative layer substantially on said first insulative layer, said second insulative layer being of a kind capable of being melted at temperatures and within time durations sufficiently small to prevent significant altering of said diffused device; melting and resolidifying said second insulative layer; and depositing metal on said second insulative layer whereby an interconnection network is provided with first means to electrically contact said doped polysilicon located at said first exposure and with second means to electrically contact said outer major surface at a second exposure thereof provided through another opening in said first insulative layer and through an opening in said second insulative layer, said second exposure located within said selected area.
Claim 11
Dependent Claim
44 words
The method of claim 8 wherein said providing of said first diffusant is accomplished by diffusing said first diffusant shallowly into said first layer through said selected area in an initial diffusion and said outer major surface is oriented in substantially a (100) orientation.
Claim 12
Dependent Claim
17 words
The method of claim 9 wherein said second diffusant is arsenic and said first layer is silicon.
Claim 13
Dependent Claim
23 words
The method of claim 10 wherein said first insulative layer is silicon dioxide and said second insulative layer is phosphorus doped silicon dioxide.
Claim 14
Dependent Claim
172 words
The method of claim 7 wherein said diffusing of said first and second diffusants simultaneously is followed by: providing a colloidal dispersion substantially on said first insulative layer, said colloidal dispersion having a first insulating material dispersed in a liquid dispersive medium and being capable of adhering to said first insulative layer and to said doped polysilicon, evaporating said liquid dispersive medium to provide a film of said first insulating material substantially on said first insulating layer, depositing a second insulating material on said film whereby a second insulative layer comprising said film and said second insulating material as deposited is provided, and depositing metal on said second insulative layer whereby an interconnection network is provided with first means to electrically contact said doped polysilicon located at said first exposure and with second means to electrically contact said outer major surface at a seconD exposure thereof provided through another opening in said first insulative layer and through an opening in said second insulative layer, said second exposure located within said selected area.
Claim 15
Dependent Claim
44 words
The method of claim 12 wherein said providing of said first diffusant is accomplished by diffusing said first diffusant shallowly into said first layer through said selected area in an initial diffusion and said outer major surface is oriented in substantially a (100) orientation.
Claim 16
Dependent Claim
17 words
The method of claim 4 wherein said second diffusant is arsenic and said first layer is silicon.
Claim 17
Dependent Claim
30 words
The method of claim 14 wherein said first insulative layer is silicon dioxide and said liquid dispersive medium is alcohol and said first and second insulating materials are silicon dioxide.
Claim 18
Dependent Claim
13 words
The method of claim 15 wherein said silicon dioxide is doped with phosphorus.
Claim 19
Dependent Claim
11 words
The method of claim 7 wherein said second diffusant is arsenic.
Claim 20
Independent Claim
249 words
A method for constructing a semiconductor device at an outer major surface of a first layer of silicon of a first conductivity type, said method comprising: providing a first diffusant at a selected area of said outer major surface, said first diffusant being of a kind tending to cause said first layer to be locally of a second conductivity type when diffused therein; providing a first insulative layer on said outer major surface with an opening in said first insulative layer to provide a first exposure of a portion of said selected area; providing arsenic as a second diffusant at said opening with i) said second diffusant as provided being of a kind to substantially diffuse behind said first diffusant, as provided, when simultaneously diffused therewith inwardly into said first layer, and ii) said second diffusant, as provided, being of a kind capable of limiting progress of a diffusion of said first diffusant, as provided along directions substantially perpendicular to said outer major surface where said second diffusant is simultaneously diffused along said directions in sufficiently close proximity to said first diffusant, relative to progress of said diffusion of said first diffusant where said second diffusant is relatively remote from said diffusion of said first diffusant; and diffusing said first and second diffusants simultaneously into said first layer whereby a diffused device results having a region of said second conductivity type that is substantially narrowed on either side thereof where interposed between two regions of said first conductivity type.
Claim 21
Independent Claim
249 words
A method for constructing a semiconductor device at an outer major surface of a first layer of silicon of a first conductivity type, said method comprising: providing a first diffusant at a selected area of said outer major surface, said first diffusant being of a kind tending to cause said first layer to be locally of a second conductivity type when diffused therein; providing a first insulative layer on said outer major surface with an opening in said first insulative layer to provide a first exposure of a portion of said selected area; providing arsenic as a second diffusant at said opening with i) said second diffusant as provided being of a kind to substantially diffuse behind said first diffusant, as provided, when simultaneously diffused therewith inwardly into said first layer, and ii) said second diffusant, as provided, being of a kind capable of limiting progress of a diffusion of said first diffusant, as provided along directions substantially perpendicular to said outer major surface where said second diffusant is simultaneously diffused along said directions in sufficiently close proximity to said first diffusant, relative to progress of said diffusion of said first diffusant where said second diffusant is relatively remote from said diffusion of said first diffusant; and diffusing said first and second diffusants simultaneously into said first layer whereby a diffused device results having a region of said second conductivity type that is substantially narrowed on either side thereof where interposed between two regions of said first conductivity type.
Claim 22
Dependent Claim
18 words
The method of claim 18 wherein said outer major surface is oriented in substantially a (100 ) orientation.
Claim 23
Dependent Claim
23 words
The method of claim 1 wherein said providing of said first diffusant is accomplished by providing boron and said first layer is silicon.
Claim 24
Dependent Claim
18 words
The method of claim 20 wherein said outer major surface is oriented in substantially a (100 ) orientation.
Claim 25
Independent Claim
421 words
A method for constructing a semiconductor device at an outer major surface of a first layer of semiconductor material of a first conductivity type, said method comprising: providing a first diffusant at a selected area of said outer major surface, said first diffusant being of a kind tending to cause said first layer to be locally of a second conductivity type when diffused therein; providing a first insulative layer on said outer major surface with an opening in said first insulative layer to provide a first exposure of a portion of said selected area; providing a second diffusant at said opening with i) said second diffusant being of a kind tending to cause said first layer to be locally of said first conductivity type when diffused therein; ii) said second diffusant, as provided, being of a kind to substantially diffuse behind said first diffusant, as provided, when simultaneously diffused therewith inwardly into said first layer, and iii) said second diffusant, as provided, being of a kind capable of limiting progress of a diffusion of said first dIffusant, as provided, along directions substantially perpendicular to said outer major surface where said second diffusant is simultaneously diffused along said directions in sufficiently close proximity to said first diffusant, relative to progress of said diffusion of said first diffusant where said second diffusant is relatively remote from said diffusion of said first diffusant; diffusing said first and second diffusants simultaneously into said first layer whereby a diffused device results having a region of said second conductivity type that is substantially narrowed on either side thereof where interposed between two regions of said first conductivity type; providing a colloidal dispersion substantially on said first insulative layer, said colloidal dispersion having a first insulating material dispersed in a liquid dispersive medium and being capable of adhering to said first insulative layer, evaporating said liquid dispersive medium to provide a film of said first insulating material substantially on said first insulating layer, depositing a second insulating material on said film whereby a second insulative layer comprising said film and said second insulating material as deposited is provided, and depositing metal on said second insulative layer whereby an interconnection network is provided with first means to electrically contact said doped polysilicon located at said first exposure and with second means to electrically contact said outer major surface at a second exposure thereof provided through another opening in said first insulative layer and through an opening in said second insulative layer, said second exposure located within said selected area.
Claim 26
Independent Claim
421 words
A method for constructing a semiconductor device at an outer major surface of a first layer of semiconductor material of a first conductivity type, said method comprising: providing a first diffusant at a selected area of said outer major surface, said first diffusant being of a kind tending to cause said first layer to be locally of a second conductivity type when diffused therein; providing a first insulative layer on said outer major surface with an opening in said first insulative layer to provide a first exposure of a portion of said selected area; providing a second diffusant at said opening with i) said second diffusant being of a kind tending to cause said first layer to be locally of said first conductivity type when diffused therein; ii) said second diffusant, as provided, being of a kind to substantially diffuse behind said first diffusant, as provided, when simultaneously diffused therewith inwardly into said first layer, and iii) said second diffusant, as provided, being of a kind capable of limiting progress of a diffusion of said first dIffusant, as provided, along directions substantially perpendicular to said outer major surface where said second diffusant is simultaneously diffused along said directions in sufficiently close proximity to said first diffusant, relative to progress of said diffusion of said first diffusant where said second diffusant is relatively remote from said diffusion of said first diffusant; diffusing said first and second diffusants simultaneously into said first layer whereby a diffused device results having a region of said second conductivity type that is substantially narrowed on either side thereof where interposed between two regions of said first conductivity type; providing a colloidal dispersion substantially on said first insulative layer, said colloidal dispersion having a first insulating material dispersed in a liquid dispersive medium and being capable of adhering to said first insulative layer, evaporating said liquid dispersive medium to provide a film of said first insulating material substantially on said first insulating layer, depositing a second insulating material on said film whereby a second insulative layer comprising said film and said second insulating material as deposited is provided, and depositing metal on said second insulative layer whereby an interconnection network is provided with first means to electrically contact said doped polysilicon located at said first exposure and with second means to electrically contact said outer major surface at a second exposure thereof provided through another opening in said first insulative layer and through an opening in said second insulative layer, said second exposure located within said selected area.
Claim 27
Independent Claim
122 words
A method for constructing a semiconductor device at an outer major surface of a first layer of n type conductivity semiconductor material, said method comprising: providing boron shallowly beneath a selected area of said outer major surface substantially uniformly across said selected area; providing a first insulative layer on said outer major surface with an opening in said first insulative layer provided to provide a first exposure of a portion of said selected area; providing said arsenic at said opening; and diffusing said boron and said arsenic simultaneously into said first layer whereby a diffused device results having a region of p type conductivity that is substantially narrowed on either side thereof where interposed between two regions of said n type conductivity.
Claim 28
Independent Claim
122 words
A method for constructing a semiconductor device at an outer major surface of a first layer of n type conductivity semiconductor material, said method comprising: providing boron shallowly beneath a selected area of said outer major surface substantially uniformly across said selected area; providing a first insulative layer on said outer major surface with an opening in said first insulative layer provided to provide a first exposure of a portion of said selected area; providing said arsenic at said opening; and diffusing said boron and said arsenic simultaneously into said first layer whereby a diffused device results having a region of p type conductivity that is substantially narrowed on either side thereof where interposed between two regions of said n type conductivity.
Claim 29
Dependent Claim
23 words
The method of claim 23 wherein said outer major surface is oriented in substantially a (100) orientation and said first layer is silicon.
Claim 30
Dependent Claim
30 words
The method of claim 23 wherein said providing of said boron is accomplished by diffusing said boron shallowly into said first layer through said selected area in an initial diffusion.
Claim 31
Dependent Claim
23 words
The method of claim 25 wherein said outer major surface is oriented substantially in a (100) orientation and said first layer is silicon.
Claim 32
Dependent Claim
33 words
The method of claim 23 wherein said providing of said arsenic is accomplished by depositing doped polysilicon on said outer major surface at said first exposure, said doped polysilicon being doped with arsenic.
Claim 33
Dependent Claim
23 words
The method of claim 27 wherein said outer major surface is oriented in substantially a (100) orientation and said first layer is silicon.
Claim 34
Dependent Claim
30 words
The method of claim 28 wherein said providing of said boron is accomplished by diffusing said boron shallowly into said first layer through said selected area in an initial diffusion.
Claim 35
Dependent Claim
113 words
The method of claim 27 wherein said diffusing of said boron and said arsenic simultaneously is followed by: providing a second insulative layer through depositing phosphorus doped silicon dioxide substantially on said first insulative layer; melting and resolidifying said second insulative layer; and depositing metal subsequently on said second insulative layer whereby an interconnection network is provided with fIrst means to electrically contact said doped polysilicon located at said first exposure and with second means to electrically contact said outer major surface at a second exposure thereof provided through another opening in said first insulative layer and through an opening in said second insulative layer, said second exposure located within said slected area.
Claim 36
Dependent Claim
48 words
The method of claim 30 wherein said providing of said boron is accomplished by diffusing said boron shallowly into said first layer through said selected area in an initial diffusion and said outer major surface is oriented in substantially a (100) orientation with said first layer being silicon.
Claim 37
Dependent Claim
19 words
The method of claim 31 wherein said providing of said first insulative layer is accomplished by depositing silicon dioxide.
Claim 38
Dependent Claim
89 words
The method of claim 32 wherein said diffusing of said boron and said arsenic simultaneously is accompanied by growing thermally a layer of silicon dioxide on said doped polysilicon for use as a mask in subsequent removal of portions of said doped polysilicon; and said diffusing of said boron and said arsenic simultaneously is followed removing a portion of said silicon dioxide thermally grown to expose a portion of said doped polysilicon, removing said portion exposed of said doped polysilicon and thereafter removing remaining said silicon dioxide thermally grown.
Claim 39
Dependent Claim
172 words
The method of claim 27 wherein said diffusing of said boron and said arsenic simultaneously is followed by: providing a colloidal dispersion substantially on said first insulative layer, said colloidal dispersion having a first insulating material dispersed in a liquid dispersive medium and being capable of adhering to said first insulative layer and to said doped polysilicon, evaporating said liquid dispersive medium to provide a film of said first insulating material substantially on said first insulating layer, depositing a second insulating material on said film whereby a second insulative layer comprising said film and said second insulating material as deposited is provided, and depositing metal on said second insulative layer whereby an interconnection network is provided with first means to electrically contact said doped polysilicon located at said first exposure and with second means to electrically contact said outer major surface at a second exposure thereof provided through another opening in said first insulative layer and through an opening in said second insulative layer, said second exposure located within said selected area.
Claim 40
Dependent Claim
48 words
The method of claim 34 wherein said providing of said boron is accomplished by diffusing said boron shallowly into said first layer through said selected area in an initial diffusion and said outer major surface is oriented in substantially a (100) orientation with said first layer being silicon.
Claim 41
Dependent Claim
19 words
The method of claim 35 wherein said providing of said first insulative layer is accomplished by depositing silicon dioxide.
Claim 42
Dependent Claim
90 words
The method of claim 36 wherein said diffusing of said boron and said arsenic simultaneously is accompanied by growing thermally a layer of silicon dioxide on said doped polysilicon for use as a mask in subsequent removal of portions of said doped polysilicon; and said diffusing of said boron and said arsenic simultaneously is followed by removing a portion of said silicon dioxide thermally grown to expose a portion of said doped polysilicon, removing said portion exposed of said doped polysilicon and thereafter removing remaining said silicon dioxide thermally grown.
Claim 43
Dependent Claim
167 words
The method of claim 23 wherein said diffusing of said boron and said arsenic simultaneously is followed by: providing a colloidal dispersion substantially on said first insulative layer, said colloidal dispersion having a first insulating material dispersed in a liquid dispersive medium and being capable of adhering to said first insulative layer, evaporating said liquid dispersive medium to provide a film of said first inSulating material substantially on said first insulating layer, depositing a second insulating material on said film whereby a second insulative layer comprising said film and said second insulating material as deposited is provided, and depositing metal on said second insulative layer whereby an interconnection network is provided with first means to electrically contact said doped polysilicon located at said first exposure and with second means to electrically contact said outer major surface at a second exposure thereof provided through another opening in said first insulative layer and through an opening in said second insulative layer, said second exposure located within said selected area.
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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) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |