US4067100A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a semiconductor device
Assignee: Individual
•
Filing: 1976-08-27
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Granted: 1978-01-10
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Expires: 1996-08-27
Abstract
Abstract A method of making a semiconductor device which has sharp corners on an upper surface and wherein a passivation layer is formed over said surface and windows are formed in the passivation layer for the attaching and formation of electrodes in which a photoresist material is placed over the passivation layer and selectively removed so as to leave areas of photoresist at locations over said passivation layer wherein electrodes are to be formed after which a layer of metal is formed over the surface and the metal and photoresist is removed at those portions where the photoresist layer remained after which passivation the area is etched through the windows in the metal layer and the metal layer is then removed and the electrodes are formed in the windows.
Inventors
- 👤 Akira Kojima
- 👤 Teruaki Aoki
- 👤 Norio Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:55
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/28; H10P50/282; H10P50/283; H10P50/60; H10P50/66; H10P50/663; H10P50/667; H10P76/00; H10P76/40
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
116 words
A method of making a semiconductor device comprising the steps of providing a semiconductor body having two major surfaces, one of said surfaces having a plurality of plane surface areas surrounded by recesses and being covered with a passivation layer forming a photoresist layer in a predetermined pattern on said plane surface areas forming a metal layer on said passivation layer and said photoresist layer, removing said photoresist layer together with those portions of said metal layer formed directly thereon to form windows and removing said passivation layer by etching through said windows, further comprising the steps of removing said metal layer, and forming a metal electrode layer on the areas exposed by said etching step.
Claim 2
Independent Claim
116 words
A method of making a semiconductor device comprising the steps of providing a semiconductor body having two major surfaces, one of said surfaces having a plurality of plane surface areas surrounded by recesses and being covered with a passivation layer forming a photoresist layer in a predetermined pattern on said plane surface areas forming a metal layer on said passivation layer and said photoresist layer, removing said photoresist layer together with those portions of said metal layer formed directly thereon to form windows and removing said passivation layer by etching through said windows, further comprising the steps of removing said metal layer, and forming a metal electrode layer on the areas exposed by said etching step.
Claim 3
Dependent Claim
13 words
A method claimed in claim 1 wherein said etching is a chemical etching.
Claim 4
Dependent Claim
13 words
A method claimed in claim 1 wherein said etching is a dry etching.
Claim 5
Independent Claim
103 words
The method of forming electrodes on a semiconductor substrate having an uneven surface covered by a passivation layer comprising the steps of covering said passivation layer with a photoresist layer and selectively exposing and developing said layer to leave photoresist on those areas where said electrodes are to be formed, coating said passivation layer and photoresist areas with a layer of metal, removing said photoresist areas and metal layer overlying said photoresist areas to form windows, etching through said passivation layer in said windows, removing the remaining portions of said metal layer, and forming metal electrodes in said windows in said passivation layer.
Claim 6
Independent Claim
103 words
The method of forming electrodes on a semiconductor substrate having an uneven surface covered by a passivation layer comprising the steps of covering said passivation layer with a photoresist layer and selectively exposing and developing said layer to leave photoresist on those areas where said electrodes are to be formed, coating said passivation layer and photoresist areas with a layer of metal, removing said photoresist areas and metal layer overlying said photoresist areas to form windows, etching through said passivation layer in said windows, removing the remaining portions of said metal layer, and forming metal electrodes in said windows in said passivation layer.
Claim 7
Dependent Claim
35 words
The method of claim 4 wherein said metal electrodes are formed by coating a second metalic layer over said passivation layer and said windows and selectively removing said second metalic layer from said passivation layer.
Claim 8
Dependent Claim
12 words
The method of claim 4 wherein said layer of metal is aluminum.
Claim 9
Dependent Claim
12 words
The method of claim 4 wherein said layer of metal is molybdenum.
Claim 10
Dependent Claim
22 words
The method of claim 4 wherein said layer of metal is formed of two layers comprising a layer of gold on chromium.
Claim 11
Dependent Claim
22 words
The method of claim 4 wherein said layer of metal is formed of two layers comprising a layer of platinum on chromium.
Claim 12
Dependent Claim
46 words
The method of claim 4 wherein said photoresist areas and metal layer overlying said photoresist areas are removed by emersing in a photoresist stripper heated to 120°-130° centigrade and subjecting the areas and layer to supersonic vibrations and peeling said areas and layer from said substrate.
Claim 13
Dependent Claim
56 words
The method of claim 4 wherein said photoresist areas and metal layer overlying said photoresist areas are removed by heating and substrate more than one minute to a temperature greater than 340° centigrade in an inert gas, then applying pressure sensitive tape to said metal layer on said substrate surface and removing said pressure sensitive tape.
Claim 14
Dependent Claim
26 words
The method of claim 4 wherein said layer of metal is aluminum or molybdenum and said passivation layer is etched by plasma etching using carbon tetrafluoride.
Claim 15
Dependent Claim
37 words
The method of claim 4 wherein said layer of metal is formed of two layers of either gold of platinum on chromium and is etched with an etchant comprising a mixture of NH 4 F-H 2 O-HF.
Claim 16
Dependent Claim
24 words
The method of claim 6 wherein said remaining portions of said metal layer are removed with hot phosphoric acid, hydrochloric acid or aqua regia.
Claim 17
Dependent Claim
43 words
The method of claim 7 wherein said remaining portions of said metal layer are removed with a solution of ceric ammonium nitrate Ce(NO 3 ) 4 .2NH 4 NO 3 .xH 2 O including a small amount of nitric acid, NHO 3 .
Claim 18
Dependent Claim
55 words
The method of claim 4 wherein said layer of metal is formed of two layers comprising gold or platinum on chromium and said remaining portions of said metal layer are removed by etching said gold or platinum with aqua regia and said chromium layer with a mixed solution of ceric ammonium nitrate and perchloric acid.
References Cited (Backward Citations)
US3287612A
Cited
US3858304A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-09 | 1981-07-11 | 1982-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-09 | 1985-07-11 | 1986-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-09 | 1989-07-11 | 1990-01-10 | $7700.00 | Window Closed / Lapsed |