Patent US4447291A successfully refreshed from Google Patents.
US4447291A
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Method for via formation in HgCdTe
Assignee: DRS Infrared Technologies LP
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Filing: 1983-08-31
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Granted: 1984-05-08
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Expires: 2003-08-31
Abstract
Abstract A via formation process for HgCdTe (i.e., for pseudo-binary alloys of HgTe and CdTe). Photoresist is patterned on the HgCdTe surface, and ion milling is used to cut holes in the HgCdTe as defined by the photoresist. With this photoresist still in place, the HgCdTe is wet etched to smooth the via walls and expand the via size to a precise dimension.
Inventors
- 👤 Eric Schulte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:39
CPC Classifications
H; H10; H10F; H10F39/00; H10F39/011; H10F39/022; H10D; H10D62/00; H10D62/80; H10D62/86; H10D62/862; H10F30/00; H10F30/20; H10F30/21; H10F30/28; H10F30/2823; H10P; H10P14/00; H10P14/60; H10P14/69; H10P14/692; H10P50/00; H10P50/20; H10P52/00; H10P95/00; H10P95/70
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
51 words
A method for forming vias in HgCdTe, comprising the steps of: ion milling a hole through said HgCdTe, said hole being substantially smaller than the desired diameter of said via; and wet etching said HgCdTe, whereby said hole is enlarged to form a via having a desired size and smooth walls.
Claim 2
Independent Claim
51 words
A method for forming vias in HgCdTe, comprising the steps of: ion milling a hole through said HgCdTe, said hole being substantially smaller than the desired diameter of said via; and wet etching said HgCdTe, whereby said hole is enlarged to form a via having a desired size and smooth walls.
Claim 3
Dependent Claim
21 words
The method of claim 1, wherein said wet etching step comprises spraying said HgCdTe with a solution of bromine and methanol.
Claim 4
Dependent Claim
22 words
The method of claim 1, wherein said wet etching step applies a solution which comprises approximately 1/8% bromine in an organic solvent.
Claim 5
Dependent Claim
30 words
The method of claim 1, further comprising the preliminary step of applying a patterned masking material to expose only a predetermined portion of said HgCdTe to said ion milling step.
Claim 6
Dependent Claim
18 words
The method of claim 4, wherein said masking material is left in place during said wet etching step.
Claim 7
Dependent Claim
12 words
The method of claim 2 wherein said solvent consists essentially of methanol.
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) | 1987-05-08 | 1987-11-07 | 1988-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-08 | 1991-11-07 | 1992-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-08 | 1995-11-07 | 1996-05-08 | $7700.00 | Window Closed / Lapsed |