US3634203A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film metallization processes for microcircuits
Assignee: Texas Instruments Inc
•
Filing: 1969-07-22
•
Granted: 1972-01-11
•
Expires: 1989-07-22
Abstract
Abstract Selective anodic oxidation is employed to pattern thin metallic films in the fabrication of printed circuit boards and integrated microcircuits to provide ''''inlaid'''' metallization geometry and thereby eliminate the need for selective etching of metal films. The total anodic conversion of metallic thin films to the corresponding oxide is demonstrated. Standard photolithographic masking techniques are employed to achieve selective anodic oxidation in the delineation of a single metal film, and also for each successive metallization layer in the fabrication of integrated microcircuits having multilevel, insulated, interconnecting metallization patterns.
Inventors
- 👤 William R Mcmahon
- 👤 Thomas H Ramsey Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:10
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10N; H10N97/00; H10W20/01; H10W20/031; H10W20/062; H10W20/064; H10W20/065; H10W74/00; H10W74/40; H10W74/43; Y; Y10; Y10S; Y10S148/00; Y10S148/043; Y10S148/106; Y10S148/117
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
38 words
A method as defined by claim 1 wherein said converting step includes the step of masking a selected area of the conductor film and selectively converting the entire thickness of the unmasked portion to a nonconductor electrolytic anodization.
Claim 2
Dependent Claim
45 words
A method as defined by claim 2 wherein the converting step comprises immersing the masked structure in an electrolytic bath, connecting the conductor as the anode of an electrolytic cell, and passing a suitable current through the cell, whereby the exposed areas are selectively oxidized.
Claim 3
Independent Claim
76 words
A method for the selective metallization of a substrate comprising: forming an insulation film on said substrate; forming openings in said insulation film at location where electrical contact is desired to subjacent material; depositing a metal film on said insulation film; selectively masking said metal film to provide a mask pattern corresponding to the desired metallization pattern; and electrolytically converting the unmasked areas of said metal film to a nonconductor to form an inlaid metallization pattern.
Claim 4
Independent Claim
87 words
A method for the selective metallization of a substrate comprising: forming an insulation film on said substrate; forming openings in said insulation film at locations where electrical contact with the substrate is desired; depositing a metal film on said insulation film; electrolytically converting a portion of the thickness of said metal film to a nonconductor; selectively masking the converted metal surface to provide thereon a mask pattern corresponding to the desired metallization pattern; and electrolytically oxidizing the remaining thickness of the unmasked area of said metal film.
Claim 5
Independent Claim
122 words
A method for the formation of a thin-film metallization pattern on a substrate comprising: forming an insulation film on said substrate; opening windows in said insulation film at locations where ohmic contact with the substrate is desired; depositing a metal film on the resulting composite; forming a first selective masking pattern on said first metal film at locations where surface contacts to said metal film are desired; electrolytically oxidizing a portion of the Thickness of the unmasked area of said metal film; forming a second selective masking pattern on the resulting partially oxidized first metal film, said pattern corresponding to the desired geometry of said metal film; and electrolytically oxidizing the remaining thickness of the unmasked areas of said first metal film:
Claim 6
Dependent Claim
32 words
A method as defined by claim 6 further including the step of depositing and patterning a second metal film on the composite surface of the structure produced in accordance with claim 6.
Claim 7
Independent Claim
118 words
A method for the fabrication of a semiconductor device comprising: forming first and second spaced apart regions of one conductivity type adjacent a surface of a semiconductor substrate of opposite conductivity type; depositing a first metal film on said surface, covering said first and second regions; electrolytically oxidizing the complete thickness of said metal film to form an insulation film adjacent said first and second regions; depositing a second metal film on said insulation film; patterning said second metal film to form a gate electrode; selectively etching the resulting oxide films to expose portions of said first and second regions of one conductivity type; and forming ohmic contacts with said first and second regions of one conductivity type.
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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |