US4297782A
Expired / Lapsed
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Method of manufacturing semiconductor devices
Assignee: Fujitsu Ltd
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Filing: 1980-01-02
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Granted: 1981-11-03
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Expires: 2000-01-02
Abstract
Abstract A method of manufacturing semiconductor devices, comprising the steps of depositing a thin metallic film on an insulative film formed on a semiconductive substrate, and projecting said thin metallic film with ion beams bombarded from above to partially inject the metal atoms of said thin metallic film into said insulative film, thereby changing the inversion threshold voltage of the surface of said semiconductive substrate. By varying the amount of the projection ion beams and the thickness and kind of said thin metallic film, the inversion threshold voltage of said semiconductive substrate can be effectively controlled.
Inventors
- 👤 Takashi Ito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:33
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/202; H10P30/204; H10D; H10D30/00; H10D30/60; H10D62/00; H10D62/10; H10D62/102; H10D62/112; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/0134; H10D64/60; H10D64/66; H10D64/68; H10D64/681; H10D64/685; H10D64/691; H10D64/693; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0135; H10D84/02; H10D84/03; H10D84/038; H10P30/208; H10P30/40; Y; Y10; Y10S; Y10S148/00; Y10S148/082; Y10S438/00; Y10S438/91
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
100 words
A method of adjusting at least one inversion threshold voltage at the surface of a semiconducting portion of a semiconductor device during the manufacture of said device, said adjusting method comprising forming a first insulative film on said surface of said semiconducting portion, forming a thin metallic film on said first insulative film, bombarding said thin metallic film with an ion beam to partially inject said thin metallic film into said first insulative film to produce negative fixed charges in said first insulative film, removing said thin metallic film, and forming a second insulative film on said first insulative film.
Claim 2
Independent Claim
100 words
A method of adjusting at least one inversion threshold voltage at the surface of a semiconducting portion of a semiconductor device during the manufacture of said device, said adjusting method comprising forming a first insulative film on said surface of said semiconducting portion, forming a thin metallic film on said first insulative film, bombarding said thin metallic film with an ion beam to partially inject said thin metallic film into said first insulative film to produce negative fixed charges in said first insulative film, removing said thin metallic film, and forming a second insulative film on said first insulative film.
Claim 3
Dependent Claim
35 words
A method as set forth in claim 1, at least one of said first and second insulative films comprising at least one material selected from the group consisting of silicon dioxide, silicon nitride, and alumina.
Claim 4
Dependent Claim
20 words
A method as set forth in claim 1, the thickness of said thin metallic film being less than 2000 A.
Claim 5
Dependent Claim
46 words
The method of claim 1, said thin metallic film comprising at least one component selected from the group consisting of Be, Al, Cr, Co, Cu, Ge, Au, In, Ir, Fe, Pb, Mn, Mo, Ni, Pd, Pt, Rh, Si, Ag, Ta, Tl, Ti, W, V and Zr.
Claim 6
Dependent Claim
18 words
The method of claim 1, said ion beam comprising a constituent of said semiconducting portion of said device.
Claim 7
Dependent Claim
17 words
The method as set forth in claim 1, said ion beam comprising ions of an inert gas.
Claim 8
Dependent Claim
19 words
The method as set forth in claim 1, said ion beam having energy approximately between 10 and 1,000 keV.
Claim 9
Dependent Claim
24 words
The method as set forth in claim 1 the dose of said ion beam being approximately 10 10 to 10 16 cm -2 .
Claim 10
Dependent Claim
43 words
The method of claim 1 comprising adjusting said inversion threshold voltage to a predetermined value by selectively adjusting the thickness of said first and second insulative films and of said thin metallic film, and the type, energy and dose of said ion beam.
Claim 11
Independent Claim
130 words
A method of adjusting in the manufacture of a semiconductor device at least one inversion threshold voltage in the field region of at least one MOSFET of said device, said method comprising the steps of forming a field insulative film on the surface of a p-type silicon semiconductive substrate in a field region of each said MOSFET, depositing a thin metallic film on the surface of said insulative film, bombarding said thin metallic film with at least one ion beam to partially inject said thin metallic film into said field insulative film to change said at least one inversion threshold voltage at at least one corresponding portion of the underlying surface of the substrate, removing said thin metallic film, and depositing a second insulating film on said field insulative film.
Claim 12
Independent Claim
130 words
A method of adjusting in the manufacture of a semiconductor device at least one inversion threshold voltage in the field region of at least one MOSFET of said device, said method comprising the steps of forming a field insulative film on the surface of a p-type silicon semiconductive substrate in a field region of each said MOSFET, depositing a thin metallic film on the surface of said insulative film, bombarding said thin metallic film with at least one ion beam to partially inject said thin metallic film into said field insulative film to change said at least one inversion threshold voltage at at least one corresponding portion of the underlying surface of the substrate, removing said thin metallic film, and depositing a second insulating film on said field insulative film.
Claim 13
Dependent Claim
46 words
The method of claim 10 comprising adjusting said at least one inversion threshold voltage to a predetermined value by selectively adjusting the thickness of each said insulative film and of each said thin metallic film and the type, energy and dose of each said ion beam.
Claim 14
Independent Claim
122 words
A method of adjusting the gate inversion threshold voltage of at least one MOSFET in the manufacture of a semiconductor device on a semiconductor substrate, said method comprising the steps of forming a first gate insulative film corresponding to the gate of each said MOSFET on the surface of the semiconductor substrate, depositing a thin metallic film on the surface of said first gate insulative film, bombarding said thin metallic film with at least one ion beam to partially inject said thin metallic film into said first gate insulative film, removing the thin metallic film, depositing a second gate insulative film on said first gate insulative film, and forming a gate electrode for each said MOSFET on the second gate insulative film.
Claim 15
Independent Claim
122 words
A method of adjusting the gate inversion threshold voltage of at least one MOSFET in the manufacture of a semiconductor device on a semiconductor substrate, said method comprising the steps of forming a first gate insulative film corresponding to the gate of each said MOSFET on the surface of the semiconductor substrate, depositing a thin metallic film on the surface of said first gate insulative film, bombarding said thin metallic film with at least one ion beam to partially inject said thin metallic film into said first gate insulative film, removing the thin metallic film, depositing a second gate insulative film on said first gate insulative film, and forming a gate electrode for each said MOSFET on the second gate insulative film.
Claim 16
Independent Claim
142 words
A method of providing gates of different threshold voltage for respective MOSFETs during the manufacture of a semiconductor device on a semiconductor substrate, said method comprising the steps of depositing a first gate insulative film to cover the gate regions of said MOSFETs on said semiconductive substrate, depositing on first and second portions of said first gate insulative film first and second thin metallic films, respectively, the first thin metallic film having a thickness different from the second thin metallic film, bombarding said thin metallic films with an ion beam to partially inject each said thin metallic film into the respective portions of said first gate insulative film, removing said thin metallic film, providing a second gate insulative film on each said injected first insulative film, and forming a plurality of gate electrodes for said MOSFETs on said second gate insulative film.
Claim 17
Independent Claim
142 words
A method of providing gates of different threshold voltage for respective MOSFETs during the manufacture of a semiconductor device on a semiconductor substrate, said method comprising the steps of depositing a first gate insulative film to cover the gate regions of said MOSFETs on said semiconductive substrate, depositing on first and second portions of said first gate insulative film first and second thin metallic films, respectively, the first thin metallic film having a thickness different from the second thin metallic film, bombarding said thin metallic films with an ion beam to partially inject each said thin metallic film into the respective portions of said first gate insulative film, removing said thin metallic film, providing a second gate insulative film on each said injected first insulative film, and forming a plurality of gate electrodes for said MOSFETs on said second gate insulative film.
Claim 18
Dependent Claim
43 words
The method of claim 13 comprising providing predetermined values for said different threshold voltages by selectively adjusting the thickness of each said gate insulative film and of each said thin metallic film and the type, energy and dose of each said ion beam.
Claim 19
Independent Claim
162 words
A method of providing gates of different threshold voltage in respective MOSFETs during the manufacture of a semiconductor device on a semiconductor substrate, said method comprising the steps of depositing a first gate insulative film covering each region on said one substrate corresponding to the gates of said MOSFETs, depositing on said first gate insulative film at each said region corresponding to said gates a respective one of at least two thin metallic films, at least one of said thin metallic films being of a material different from each other of said thin metallic films, bombarding said thin metallic films with at least one ion beam to partially inject each said thin metallic film into said first gate insulative film, removing said thin metallic films, depositing at least one respective second gate insulative film on said first gate insulative film on said regions corresponding to said gates, and forming a plurality of gate electrodes of said MOSFETs on said gate insulative films.
Claim 20
Independent Claim
162 words
A method of providing gates of different threshold voltage in respective MOSFETs during the manufacture of a semiconductor device on a semiconductor substrate, said method comprising the steps of depositing a first gate insulative film covering each region on said one substrate corresponding to the gates of said MOSFETs, depositing on said first gate insulative film at each said region corresponding to said gates a respective one of at least two thin metallic films, at least one of said thin metallic films being of a material different from each other of said thin metallic films, bombarding said thin metallic films with at least one ion beam to partially inject each said thin metallic film into said first gate insulative film, removing said thin metallic films, depositing at least one respective second gate insulative film on said first gate insulative film on said regions corresponding to said gates, and forming a plurality of gate electrodes of said MOSFETs on said gate insulative films.
Claim 21
Dependent Claim
49 words
The method of claim 15 comprising providing predetermined values for said different threshold voltages by selectively adjusting the thickness of each said gate insulative film, the type of material and the thicknesses of each said thin metallic film, and the type, energy and dose of each said ion beam.
Claim 22
Dependent Claim
40 words
The method of claim 9, 10, 11, 12, 13, or 15, each said thin metallic film being partially injected into said first insulative film to have a surface density of approximately between 10 10 and 10 16 /cm 2 .
Claim 23
Dependent Claim
26 words
The method of claim 9, 10, 11, 12, 13 or 15, comprising forming each said thin metallic layer to have thickness less than approximately 2000 A.
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) | 1984-11-02 | 1985-05-04 | 1985-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-02 | 1989-05-04 | 1989-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-02 | 1993-05-04 | 1993-11-03 | $7700.00 | Window Closed / Lapsed |