Patent US3894872A successfully refreshed from Google Patents.
US3894872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Technique for fabricating high Q MIM capacitors
Assignee: RCA Corp
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Filing: 1974-07-17
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Granted: 1975-07-15
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Expires: 1994-07-17
Abstract
Abstract A process for making an MIM (metal-insulator-metal) capacitor comprising thermally depositing or growing a dielectric on a silicon substrate, depositing an electrode on the dielectric, removing the silicon substrate, thereby exposing the dielectric, and depositing a second electrode on the exposed dielectric is disclosed.
Inventors
- 👤 Jr Joseph Mitchell
- 👤 Jr Lester Andrew Carr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:40
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; Y; Y10; Y10S; Y10S438/00; Y10S438/977; Y10T; Y10T29/00; Y10T29/43; Y10T29/435
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
53 words
A METHOD OF MAKING A CAPACITOR COMPRISING: A. THERMALLY DEPOSITING OR GROWING A LAYER OF DIELECTRIC ON A SILICON SUBSTRATE: B. DEPOSITING A FIRST ELECTRODE ON THE SURFACE OF SAID DIELECTRIC LAYER C. REMOVING SAID SILICON SUBSTRATE, THEREBY EXPOSING SAID DIELECTRIC LAYER: AND D. DEPOSITING A SECOND ELECTRODE ON SAID EXPOSED DIELECTRIC LAYER.
Claim 2
Independent Claim
53 words
A METHOD OF MAKING A CAPACITOR COMPRISING: A. THERMALLY DEPOSITING OR GROWING A LAYER OF DIELECTRIC ON A SILICON SUBSTRATE: B. DEPOSITING A FIRST ELECTRODE ON THE SURFACE OF SAID DIELECTRIC LAYER C. REMOVING SAID SILICON SUBSTRATE, THEREBY EXPOSING SAID DIELECTRIC LAYER: AND D. DEPOSITING A SECOND ELECTRODE ON SAID EXPOSED DIELECTRIC LAYER.
Claim 3
Dependent Claim
14 words
A method according to claim 1 wherein said dielectric is thermally grown silicon dioxide.
Claim 4
Dependent Claim
19 words
A method according to claim 2 wherein said silicon dioxide is grown by steam oxidation of said silicon substrate.
Claim 5
Dependent Claim
12 words
A method according to claim 1 wherein said dielectric is silicon nitride.
Claim 6
Dependent Claim
32 words
A method according to claim 4 wherein said silicon nitride is deposited by passing a mixture of silicon tetrachloride and ammonia over said silicon substrate heated at a temperature of about 1000*C.
Claim 7
Dependent Claim
28 words
A method according to claim 4 wherein said silicon nitride is deposited by passing a mixture of silane and ammonia over said silicon substrate heated to about 800*C.
Claim 8
Dependent Claim
12 words
A METHOD ACCORDING TO CLAIM 1 WHEREIN SAID DIELECTRIC IS ALUMINIUM OXIDE.
Claim 9
Dependent Claim
29 words
A method according to claim 1 wherein said first and second electrodes are layers of a metal selected from the group consisting of chromium, copper, aluminum, gold and silver.
Claim 10
Dependent Claim
19 words
A method according to claim 1 wherein said first and second electrode comprise successive layers of chromium and copper.
Claim 11
Dependent Claim
58 words
A method according to claim 1 wherein said capacitor is completed by the steps of: a. masking one of said electrodes; b. covering the unmasked electrode with a photoresist; c. exposing and developing said photomask to reveal a desired pattern on said unmasked electrode; d. etching said revealed electrode; and e. removing said remaining photoresist and said mask.
Claim 12
Dependent Claim
17 words
A method according to claim 1 wherein a plurality of capacitors are made from said silicon substrate.
Claim 13
Dependent Claim
119 words
A METHOD ACCORDING TO CLAIM 11 WHEREIN SAID CAPACITORS ARE COMPLETED BY THE STEPS OF: A. SEPARATING SAID DIELECTRIC INTO ISLANDS ON SAID FIRST ELECTRODE: B. DEPOSITING A LAYER OF A CONDUCTIVE METAL ON SAID DIELECTRIC ISLANDS AND SAID FIRST ELECTRODE: C. COATING SAID METAL LAYER WITH A PHOTORESIST: D. EXPOSING THE DEVELOPNG SAID PHOTORESIST SO AS TO REVEAL ONLY PORTIONS OF THE SURFACES OF SAID METAL LAYER DISPOSED DIRECTLY ON SAID DIELECTRIC ISLANDS: E. COATING SAID REVEALED METAL LAYWR WITH A SECOND LAYER OF A CONDUCTIVE METAL: F. COATING SAID SECOND METAL LAYER WITH A PROTECTIVE LAYER OF A CONDUCTIVE METAL: G. REMOVING THE REMAINING PHOTORESIST: ABD H. ETCHING AWAY SAID FIRST METAL LAYER NEATH SAID REMAINING PHOTORESIST.
Claim 14
Dependent Claim
12 words
A method according to claim 12 wherein the resulting capacitors are separated.
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) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |