US3787962A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Insulated gate field effect transistors and method of producing the same
Assignee: Hitachi Ltd
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Filing: 1971-05-13
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Granted: 1974-01-29
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Expires: 1991-05-13
Abstract
Abstract An insulated gate field effect transistor formed on one main surface of a semiconductor substrate comprising: a drain region of which the concentration of impurity is lower than twice that of the semiconductor substrate and the conductivity type is reverse to that of the substrate; and a region with a high concentration of impurity, formed in the low impurity concentration region, of which the conductivity type is the same as that of the low impurity concentration region.
Inventors
- 👤 I Yoshida
- 👤 T Ikeda
- 👤 T Tokuyama
- 👤 S Nishimatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:25
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/601; H10D30/603; H10D62/00; H10D62/10; H10D62/124; H10D62/126; H10D99/00; H10P; H10P30/00; H10P30/20; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/053
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
266 words
A method of producing an insulated gate field effect transistor, comprising the steps of: a. providing an insulation film on the surface of a semiconductor substrate of a first conductivity type; b. providing a layer of material capable of forming a gate electrode on said insulation film; c. forming first and second apertures of prescribed shapes separated from each other by a specified distance in said layer of material, and thereby forming a gate electrode, between said first and second apertures, on said insulation film; d. irradiating a first beam of ions of an impurity of a second conductivity type opposite said first conductivity type onto the surface of said substrate, said gate electrode masking the surface portion of said substrate therebeneath against said first beam of ions and thereby providing low impurity concentration regions of said second conductivity type respectively corResponding to source and drain regions in first and second surface portions of said substrate disposed directly beneath said first and second apertures in said layer of material, with the extent of the portion of said substrate between said first and second surface portions thereof being defined by said gate electrode disposed thereabove on said insulation film; e. forming an ion implantation preventing mask film on the surface portion of said insulation film adjacent said gate electrode which has been exposed by said second aperture; and f. irradiating a second beam of ions of said impurity of said second conductivity type onto the surface of said substrate, and thereby forming high impurity concentration regions of said second conductivity type in said source and drain regions.
Claim 2
Independent Claim
266 words
A method of producing an insulated gate field effect transistor, comprising the steps of: a. providing an insulation film on the surface of a semiconductor substrate of a first conductivity type; b. providing a layer of material capable of forming a gate electrode on said insulation film; c. forming first and second apertures of prescribed shapes separated from each other by a specified distance in said layer of material, and thereby forming a gate electrode, between said first and second apertures, on said insulation film; d. irradiating a first beam of ions of an impurity of a second conductivity type opposite said first conductivity type onto the surface of said substrate, said gate electrode masking the surface portion of said substrate therebeneath against said first beam of ions and thereby providing low impurity concentration regions of said second conductivity type respectively corResponding to source and drain regions in first and second surface portions of said substrate disposed directly beneath said first and second apertures in said layer of material, with the extent of the portion of said substrate between said first and second surface portions thereof being defined by said gate electrode disposed thereabove on said insulation film; e. forming an ion implantation preventing mask film on the surface portion of said insulation film adjacent said gate electrode which has been exposed by said second aperture; and f. irradiating a second beam of ions of said impurity of said second conductivity type onto the surface of said substrate, and thereby forming high impurity concentration regions of said second conductivity type in said source and drain regions.
Claim 3
Dependent Claim
47 words
A method of producing an insulated gate field effect transistor in accordance with claim 1, wherein the semiconductor substrate is kept heated at a temperature of 600* to 800*C during the step for forming the low impurity concentration region and high impurity concentration region by ion implantation.
Claim 4
Dependent Claim
43 words
A method of producing an insulated gate field effect transistor in accordance with claim 1, characterized in that the semiconductor substrate is heated at a temperature of 600* to 800*C after the step for forming the low impurity concentration region by ion implantation.
Claim 5
Dependent Claim
41 words
A method of producing an insulated gate field effect transistor in accordance with claim 1, wherein the semiconductor substrate is heated at a temperature of 600* to 800*C after the step for forming the high impurity concentration region by ion implantation.
Claim 6
Dependent Claim
58 words
A method of producing an insulated gate field effect transistor in accordance with claim 1, wherein the energy of ion implantation is determined so that the impurity concentration of said low impurity concentration region is kept smaller than that of said substrate during ion implantation in the step for forming the low impurity concentration region by ion implantation.
Claim 7
Dependent Claim
38 words
A method of producing an insulated gate field effect transistor in accordance with claim 1, wherein said material layer which can form the gate electrode and is disposed on said insulation film, is formed of a metal layer.
Claim 8
Dependent Claim
38 words
A method of producing an insulated gate field effect transistor in accordance with claim 1, wherein said material layer which can form the gate electrode and is disposed on said insulation film, is formed of a semiconductor layer.
Claim 9
Independent Claim
307 words
A method of producing an insulated gate field effect transistor comprising the steps of: a. providing an insulation film on the surface of a semiconductor substrate of a first conductivity type; b. providing a gate electrode on said insulation film; c. irradiating a first beam of ions of an impurity material of a second conductivity type opposite said first conductivity type onto said substrate, said gate electrode masking a first surface portion of the substrate therebeneath against said first beam of ions, and thereby forming a drain region in a second surface portion of said substrate, said second surface portion being adjacent said first surface portion of said substrate; d. forming an ion implantation preventing mask film on the surfaces of said insulation film and said gate electrode; e. forming a first aperture in said ion implantation preventing mask film and thereby exposing a first surface portion of said insulation film above a third surface portion of said substrate which is separated from said drain region by said first surface portion of said substrate; f. forming a second aperture in said ion implantation preventing mask film and thereby exposing a second surface portion of said insulation film above a first portion of said drain region, with one edge of said second aperture being positioned above one end of said first portion of said drain region which is separated from the boundary of said drain region and saId first surface portion of the substrate; and g. irradiating a second beam of ions of an impurity having said second conductivity type onto the surface of said substrate, and thereby forming a first high impurity concentration region in said third surface portion of said substrate directly beneath said first aperture and a second high impurity concentration region in said first portion of said drain region directly beneath said second aperture.
Claim 10
Independent Claim
307 words
A method of producing an insulated gate field effect transistor comprising the steps of: a. providing an insulation film on the surface of a semiconductor substrate of a first conductivity type; b. providing a gate electrode on said insulation film; c. irradiating a first beam of ions of an impurity material of a second conductivity type opposite said first conductivity type onto said substrate, said gate electrode masking a first surface portion of the substrate therebeneath against said first beam of ions, and thereby forming a drain region in a second surface portion of said substrate, said second surface portion being adjacent said first surface portion of said substrate; d. forming an ion implantation preventing mask film on the surfaces of said insulation film and said gate electrode; e. forming a first aperture in said ion implantation preventing mask film and thereby exposing a first surface portion of said insulation film above a third surface portion of said substrate which is separated from said drain region by said first surface portion of said substrate; f. forming a second aperture in said ion implantation preventing mask film and thereby exposing a second surface portion of said insulation film above a first portion of said drain region, with one edge of said second aperture being positioned above one end of said first portion of said drain region which is separated from the boundary of said drain region and saId first surface portion of the substrate; and g. irradiating a second beam of ions of an impurity having said second conductivity type onto the surface of said substrate, and thereby forming a first high impurity concentration region in said third surface portion of said substrate directly beneath said first aperture and a second high impurity concentration region in said first portion of said drain region directly beneath said second aperture.
Claim 11
Dependent Claim
70 words
A method of producing an insulated gate field effect transistor in accordance with claim 1, wherein said step (e) comprises forming said ion implantation preventing mask film so as to extend on said insulation film from one edge of said gate electrode to a first surface portion of said insulation film above said drain region, while leaving a second surface portion of said insulation film above said drain region exposed.
Claim 12
Independent Claim
284 words
A method of producing an insulated gate field effect transistor comprising the steps of: a. providing an insulation film on the surface of a semiconductor substrate of a first conductivity type; b. providing a gate electrode on said insulation film, c. irradiating a first beam of ions of an impurity material of a second conductivity type opposite said first conductivity type onto said substrate, said gate electrode masking a first surface portion of the substrate therebeneath against said first beam of ions, and thereby forming a drain region in a second surface portion of said substrate, said second surface portion being adjacent said first surface portion of said substrate; d. forming an ion implantation preventing mask film on the surfaces of said insulation film and said gate electrode; e. forming a first aperture in said ion implantation preventing mask film and thereby exposing a first portion of said insulation film above a third surface portion of said substrate which is separated from said drain region by said first surface portion of said substrate; f. forming a second aperture in said ion implantation preventing mask film and thereby exposing a second surface portion of said insulation film above a first portion of said drain region, with one edge of said second aperture being positioned above one end of said first portion of said drain region which is separated from the boundary of said drain region and said first surface portion of the substrate; and g. forming a first high impurity concentration region in said third surface portion of said substrate directly beneath said first aperture and a second high impurity concentration region in said first portion of said drain region directly beneath said second aperture.
Claim 13
Independent Claim
284 words
A method of producing an insulated gate field effect transistor comprising the steps of: a. providing an insulation film on the surface of a semiconductor substrate of a first conductivity type; b. providing a gate electrode on said insulation film, c. irradiating a first beam of ions of an impurity material of a second conductivity type opposite said first conductivity type onto said substrate, said gate electrode masking a first surface portion of the substrate therebeneath against said first beam of ions, and thereby forming a drain region in a second surface portion of said substrate, said second surface portion being adjacent said first surface portion of said substrate; d. forming an ion implantation preventing mask film on the surfaces of said insulation film and said gate electrode; e. forming a first aperture in said ion implantation preventing mask film and thereby exposing a first portion of said insulation film above a third surface portion of said substrate which is separated from said drain region by said first surface portion of said substrate; f. forming a second aperture in said ion implantation preventing mask film and thereby exposing a second surface portion of said insulation film above a first portion of said drain region, with one edge of said second aperture being positioned above one end of said first portion of said drain region which is separated from the boundary of said drain region and said first surface portion of the substrate; and g. forming a first high impurity concentration region in said third surface portion of said substrate directly beneath said first aperture and a second high impurity concentration region in said first portion of said drain region directly beneath said second aperture.
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) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |