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US4496435A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of manufacturing thin film circuits

Assignee: NEC Corp
•
Filing: 1984-02-07
•
Granted: 1985-01-29
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Expires: 2004-02-07
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Abstract

Abstract A thin film circuit including resistor elements and capacitor elements is prepared by forming a tantalum film for capacitor on an insulating substrate, forming a tantalum film for resistor over the substrate, covering a predetermined region of the tantalum resistor film with a titanium film, heat treating a resulting assembly, removing the titanium film, and then covering the predetermined region with a metal film to provide ohmic contact therebetween.

Inventors

  • 👤 Keiji Harada
  • 👤 Akio Sato

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 14:21
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/01; H10D86/00; H10D86/01

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 54 words
A method of manufacturing a thin film circuit comprising the steps of: forming a tantalum film on insulating substrate; covering a predetermined region of said tantalum film with a titanium film; heat treating a resulting assembly; removing said titanium film; and covering said predetermined region with a metal film to provide ohmic contact therebetween.
Claim 2
Independent Claim 54 words
A method of manufacturing a thin film circuit comprising the steps of: forming a tantalum film on insulating substrate; covering a predetermined region of said tantalum film with a titanium film; heat treating a resulting assembly; removing said titanium film; and covering said predetermined region with a metal film to provide ohmic contact therebetween.
Claim 3
Dependent Claim 16 words
The method according to claim 1 wherein said metal film comprises nichrome, palladium and gold layers.
Claim 4
Independent Claim 171 words
A method of forming a thin film circuit including capacitor elements and resistor elements which are formed on the same insulating substrate, comprising the steps of: forming a tantalum film for capacitor on said insulating substrate; etching said tantalum capacitor film to form a predetermined circuit pattern; anodizing a portion of said tantalum capacitor film to convert said portion into a dielectric layer of said capacitor; forming a tantalum film for resistor on the entire surface of said substrate; forming a titanium film on said tantalum resistor film; patterning said titanium film to remove a portion thereof except portions at which conductor patterns and external lead terminal connectors are formed; patterning said tantalum resistor film to form the resistor element; removing a portion of said tantalum resistor film overlying said dielectric layer; heat treating said resistor element for stabilizing the same; etching off said titanium film; forming a metal film on the entire substrate; and patterning said metal film to form terminals or conductor patterns of said resistor and capacitor elements.
Claim 5
Independent Claim 171 words
A method of forming a thin film circuit including capacitor elements and resistor elements which are formed on the same insulating substrate, comprising the steps of: forming a tantalum film for capacitor on said insulating substrate; etching said tantalum capacitor film to form a predetermined circuit pattern; anodizing a portion of said tantalum capacitor film to convert said portion into a dielectric layer of said capacitor; forming a tantalum film for resistor on the entire surface of said substrate; forming a titanium film on said tantalum resistor film; patterning said titanium film to remove a portion thereof except portions at which conductor patterns and external lead terminal connectors are formed; patterning said tantalum resistor film to form the resistor element; removing a portion of said tantalum resistor film overlying said dielectric layer; heat treating said resistor element for stabilizing the same; etching off said titanium film; forming a metal film on the entire substrate; and patterning said metal film to form terminals or conductor patterns of said resistor and capacitor elements.
Claim 6
Dependent Claim 16 words
The method according to claim 3 wherein said tantalum resistor film is a tantalum nitride film.
Claim 7
Dependent Claim 18 words
The method according to claim 3 wherein said tantalum resistor film is an oxygen doped tanalum nitride film.
Claim 8
Dependent Claim 16 words
The method according to claim 3 wherein said metal film comprises nichrome, palladium and gold layers.
Claim 9
Dependent Claim 18 words
The method according to claim 3 wherein said tantalum capacitor film has a thickness of about 5000 Å.
Claim 10
Dependent Claim 18 words
The method according to claim 3 wherein said tantalum resistor film has a thickness of about 800 Å.
Claim 11
Dependent Claim 17 words
The method according to claim 3 wherein said titanium film has a thickness of about 700 Å.
Claim 12
Dependent Claim 21 words
The method according to claim 3 wherein said resistor element is heat treated in air for 5 hours at 50° C.
Claim 13
Dependent Claim 27 words
The method according to claim 3 wherein said three layers of nichrome, palladium and gold respectively have thicknesses of about 500 Å, 2000 Å and 6000 Å.

References Cited (Backward Citations)

US3607679A Cited
US4251326A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-01-29 1988-07-30 1989-01-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-01-29 1992-07-30 1993-01-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-01-29 1996-07-30 1997-01-29 $7700.00 Window Closed / Lapsed

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