US3953266A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for fabricating a semiconductor device
Assignee: Individual
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Filing: 1973-03-15
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Granted: 1976-04-27
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Expires: 1993-03-15
Abstract
Abstract A method of fabricating a semiconductor composite comprises providing a semiconductor substrate having a platinum layer, masking the platinum layer with a chromium mask layer, applying a patterned photoresist layer over the chromium mask layer, etching away portions of the chromium mask layer in accordance with the pattern of the photoresist layer to accordingly pattern the chromium mask layer, then etching away portions of the platinum layer in accordance with the etched chromium layer, and finally removing the remaining portions of the chromium mask layer. The chromium layer is interposed between the platinum and photoresist layers due to its excellent adhesive compatibility with both the platinum and the photoresist layers and the presence of the chromium layer effectively prevents the etching solution for the platinum from penetrating between the platinum and photoresist layers.
Inventors
- 👤 Toshio Takai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:12
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/40; H10W74/47; H10P; H10P76/00; H10P76/20; H10P95/00; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/40; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10P14/66; H10P14/662; H10P14/69; H10P14/692; H10P14/6921; H10P14/69215; H10P14/694; H10P14/6943; H10P14/69433; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
218 words
A process for producing a semiconductor composite comprising the steps of: a. providing a semiconductor substrate having on a surface portion thereof a layer of platinum formed on a layer of a titanium; b. masking said platinum layer with a mask layer of chromium; c. masking a portion of said chromium mask layer with a layer of photoresist patterned in accordance with a predetermined pattern; d. selectively etching away only the non-masked portion of said chromium mask layer so that the masked portion of said chromium mask layer remains on said platinum layer; e. then, selectively etching away only the portion of said platinum layer not masked by the chromium mask layer remaining on the platinum layer, so that the mask portion of said platinum layer remains on said titanium layer; f. completely removing said photoresist mask layer subsequent to the aforesaid step (d); g. completely removing said chromium mask layer remaining on said platinum layer subsequent to the removal of the photoresist layer; h. forming a layer of gold on said portion of said platinum layer remaining on said titanium layer by gold-electroplating; i. forming a gold beam lead on said gold layer by gold-electroplating, and then j. selectively etching away said titanium layer in accordance with the pattern of said gold layer on said platinum layer.
Claim 2
Dependent Claim
218 words
A process for producing a semiconductor composite comprising the steps of: a. providing a semiconductor substrate having on a surface portion thereof a layer of platinum formed on a layer of a titanium; b. masking said platinum layer with a mask layer of chromium; c. masking a portion of said chromium mask layer with a layer of photoresist patterned in accordance with a predetermined pattern; d. selectively etching away only the non-masked portion of said chromium mask layer so that the masked portion of said chromium mask layer remains on said platinum layer; e. then, selectively etching away only the portion of said platinum layer not masked by the chromium mask layer remaining on the platinum layer, so that the mask portion of said platinum layer remains on said titanium layer; f. completely removing said photoresist mask layer subsequent to the aforesaid step (d); g. completely removing said chromium mask layer remaining on said platinum layer subsequent to the removal of the photoresist layer; h. forming a layer of gold on said portion of said platinum layer remaining on said titanium layer by gold-electroplating; i. forming a gold beam lead on said gold layer by gold-electroplating, and then j. selectively etching away said titanium layer in accordance with the pattern of said gold layer on said platinum layer.
Claim 3
Dependent Claim
20 words
A process according to claim 1 wherein the thickness of said chromium mask layer is from 1000 to 5000 A.
Claim 4
Dependent Claim
20 words
A process according to claim 2, wherein the thickness of said chromium mask layer is from 2000 to 4000 A.
Claim 5
Dependent Claim
25 words
A process according to claim 1, wherein said first-mentioned etching step is carried out using a mixed aqueous solution of KOH and KMnO 4 .
Claim 6
Dependent Claim
22 words
A process according to claim 1, wherein said second-mentioned etching step is carried out using a mixture of HNO 3 and HCl.
Claim 7
Dependent Claim
16 words
A process according to claim 1 wherein said masking step is achieved by a sputtering method.
Claim 8
Dependent Claim
17 words
A process according to claim 1, wherein said masking step is achieved by a vacuum evaporation method.
Claim 9
Dependent Claim
19 words
A process according to claim 1, wherein completely removing said photoresist layer is subsequent to the etching step (e).
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) | 1979-04-27 | 1979-10-27 | 1980-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-27 | 1983-10-27 | 1984-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-27 | 1987-10-27 | 1988-04-27 | $7700.00 | Window Closed / Lapsed |