US4814293A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing a semiconductor device
Assignee: US Philips Corp
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Filing: 1988-05-06
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Granted: 1989-03-21
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Expires: 2008-05-06
Abstract
Abstract The invention relates to the manufacture of a semiconductor device, in which a titanium-tungsten layer (5) must be etched. In order to obtain a homogeneous course of the etching process, according to the invention, the etching is effected in a buffered hydrogen peroxide solution having a pH between 1 and 6.
Inventors
- 👤 Jacques J. Van Oekel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:51
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C23F1/26; H; H10; H10P; H10P50/00; H10P50/60; H10P50/66; H10P50/663; H10P50/667; H10P50/71
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
71 words
A method of manufacturing a semiconductor device, in which a titanium-tungsten layer is provided on a substrate and a layer masking during etching of the titanium-tungsten layer is provided on this layer, after which the titanium-tungsten layer is etched in an etching solution of hydrogen peroxide in water, characterized in that the pH of the etching solution is adjusted by means of a buffer to a value between 1 and 6.
Claim 2
Independent Claim
71 words
A method of manufacturing a semiconductor device, in which a titanium-tungsten layer is provided on a substrate and a layer masking during etching of the titanium-tungsten layer is provided on this layer, after which the titanium-tungsten layer is etched in an etching solution of hydrogen peroxide in water, characterized in that the pH of the etching solution is adjusted by means of a buffer to a value between 1 and 6.
Claim 3
Dependent Claim
18 words
A method as claimed in claim 1, characterized in that the cation used in the buffer is ammonium.
Claim 4
Dependent Claim
21 words
A method as claimed in claim 2, characterized in that the acid used in the buffer is preferably an organic acid.
Claim 5
Dependent Claim
17 words
A method as claimed in claim 3, characterized in that acetic acid or citric acid is used.
Claim 6
Dependent Claim
20 words
A method as claimed in claim 4, characterized in that a buffer of acetic acid and ammonium acetate is used.
Claim 7
Dependent Claim
23 words
A method as claimed in claim 5 characterized in that the concentration of hydrogen peroxide in the etching solution is 25 to 30%.
Claim 8
Dependent Claim
19 words
A method as claimed in claim 6, characterized in that an aluminium layer is used as the masking layer.
Claim 9
Dependent Claim
19 words
A method as claimed in claim 6, characterized in that a photoresist layer is used as the masking layer.
Claim 10
Dependent Claim
23 words
A method as claimed in claim 4, characterized in that the concentration of hydrogen peroxide in the etching solution is 25 to 30%.
Claim 11
Dependent Claim
23 words
A method as claimed in claim 3, characterized in that the concentration of hydrogen peroxide in the etching solution is 25 to 30%.
Claim 12
Dependent Claim
23 words
A method as claimed in claim 1, characterized in that the concentration of hydrogen peroxide in the etching solution is 25 to 30%.
Claim 13
Dependent Claim
19 words
A method as claimed in claim 3, characterized in that an aluminum layer is used as the masking layer.
Claim 14
Dependent Claim
19 words
A method as claimed in claim 11, characterized in that an aluminum layer is used as the masking layer.
Claim 15
Dependent Claim
19 words
A method as claimed in claim 1, characterized in that an aluminum layer is used as the masking layer.
Claim 16
Dependent Claim
19 words
A method as claimed in claim 3, characterized in that a photoresist layer is used as the masking layer.
Claim 17
Dependent Claim
19 words
A method as claimed in claim 11, characterized in that a photoresist layer is used as the masking layer.
Claim 18
Dependent Claim
19 words
A method as claimed in claim 1, characterized in that a photoresist layer is used as the masking layer.
Claim 19
Dependent Claim
21 words
A method as claimed in claim 1, characterized in that the acid used in the buffer is preferably an organic acid.
Claim 20
Dependent Claim
17 words
A method as claimed in claim 18, characterized in that acetic acid or citric acid is used.
Claim 21
Dependent Claim
23 words
A method as claimed in claim 18, characterized in that the concentration of hydrogen peroxide in the etching solution is 25 to 30%.
References Cited (Backward Citations)
SU707949A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |