US4256534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device fabrication by plasma etching
Assignee: AT&T Inc
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Filing: 1978-07-31
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Granted: 1981-03-17
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Expires: 1998-07-31
Abstract
Abstract Integrated circuit fabrication, e.g., silicon LSI is expedited by plasma etching in any of a novel class of etchants. Appropriate plasma environments are produced by introduction of halide-halogen combinations as exemplified by BCl3-Cl2.
Inventors
- 👤 Hyman J. Levinstein
- 👤 David N. Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:40
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/20; H10P70/27; H10P70/273; C; C23; C23F; C23F4/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
173 words
Process for fabrication of an article comprising at least one operation during which the article undergoing fabrication comprises a surface of material to be etched, wherein the said article is etched within a plasma environment contained within an apparatus, the plasma resulting from imposition of an electrical field across a gaseous mixture between two electrodes, the material to be etched comprising an elemental aluminum-rich composition, etching being primarily due to chemical reaction with the said material to be etched characterized in that the said gaseous mixture comprises a mixture of BCl 3 and Cl 2 which in the said plasma results in the said chemical reaction in which the Cl 2 content in the said gaseous mixture is from 0.1 volume percent to 20 volume percent expressed as a percent of the total content of BCl 3 plus Cl 2 and further in which pressure and power within the plasma environment are maintained, respectively, within the limits of from 0.05 torr to 1 torr and from 0.035 watts/cm 2 0.7 watts/cm 2 .
Claim 2
Dependent Claim
173 words
Process for fabrication of an article comprising at least one operation during which the article undergoing fabrication comprises a surface of material to be etched, wherein the said article is etched within a plasma environment contained within an apparatus, the plasma resulting from imposition of an electrical field across a gaseous mixture between two electrodes, the material to be etched comprising an elemental aluminum-rich composition, etching being primarily due to chemical reaction with the said material to be etched characterized in that the said gaseous mixture comprises a mixture of BCl 3 and Cl 2 which in the said plasma results in the said chemical reaction in which the Cl 2 content in the said gaseous mixture is from 0.1 volume percent to 20 volume percent expressed as a percent of the total content of BCl 3 plus Cl 2 and further in which pressure and power within the plasma environment are maintained, respectively, within the limits of from 0.05 torr to 1 torr and from 0.035 watts/cm 2 0.7 watts/cm 2 .
Claim 3
Dependent Claim
23 words
Process of claim 1 in which the Cl 2 content on the same basis is from 0.5 volume percent to 8 volume percent.
Claim 4
Dependent Claim
17 words
Process of claim 1 in which the said aluminum-rich material contains at least 50 at. percent aluminum.
Claim 5
Dependent Claim
17 words
Process of claim 1 in which the said aluminum-rich material contains at least 75 at. percent aluminum.
Claim 6
Dependent Claim
15 words
Process of claim 4 in which the said aluminum-rich surface consists essentially of elemental aluminum.
Claim 7
Dependent Claim
31 words
Process of claim 4 in which the said aluminum-rich surface consists essentially of an alloy of aluminum and at least one element selected from the group consisting of silicon and copper.
Claim 8
Dependent Claim
26 words
Process of claim 6 in which the said aluminum-rich material consists essentially of from zero to 5 percent silicon, zero to 5 percent copper, remainder aluminum.
Claim 9
Dependent Claim
23 words
Process of claims 1, 2, 3, 4, 5, 6, or 7 in which etching is limited to selected regions of the said surface.
Claim 10
Dependent Claim
21 words
Process of claim 8 in which the said selected regions correspond with regions bared through apertures of an overlying masking layer.
Claim 11
Dependent Claim
18 words
Process of claim 9 in which the said masking layer consists essentially of an organic resist masking layer.
Claim 12
Dependent Claim
21 words
Process of claim 1 in which minimum pressure-power values lie between 0.5 torr-0.28 watts/cm 2 and 0.2 torr-0.035 watts/cm 2 .
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) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |