US4448634A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for polishing III-V-semiconductor surfaces
Assignee: Siltronic AG
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Filing: 1983-07-15
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Granted: 1984-05-15
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Expires: 2003-07-15
Abstract
Abstract Surfaces of III-V-semiconductors, especially gallium phosphide surfaces, can be polished very successfully if, in the polishing operation, an alkali metal hypochlorite solution adjusted to a pH value of from 8.5 to 11 by the addition of buffering components, and a liquid containing in addition to the mechanical polishing component a complex-forming component, are applied to the surface to be polished.
Inventors
- 👤 Ingolf Lampert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:43
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/12; H10P90/126; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/646; H10P52/00; H10P52/40; H10P52/402
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
79 words
In a process for polishing III-V semiconductor surfaces, in which, in the polishing operation, a solution containing an alkali metal hypochlorite and a liquid containing a mechanical polishing component are applied to the surface to be polished, the improvement comprising the steps of: adjusting the solution containing the alkali metal hypochlorite to a pH value of from 8.5 to 11 by the addition of buffering components; and adding a complex-forming component to the liquid containing the mechanical polishing component.
Claim 2
Dependent Claim
79 words
In a process for polishing III-V semiconductor surfaces, in which, in the polishing operation, a solution containing an alkali metal hypochlorite and a liquid containing a mechanical polishing component are applied to the surface to be polished, the improvement comprising the steps of: adjusting the solution containing the alkali metal hypochlorite to a pH value of from 8.5 to 11 by the addition of buffering components; and adding a complex-forming component to the liquid containing the mechanical polishing component.
Claim 3
Dependent Claim
24 words
The process of claim 1, wherein said complex-forming component is selected from the group consisting of oxalates, citrates and tartrates and a combination thereof.
Claim 4
Dependent Claim
25 words
The process of claim 1, additionally including the step of applying said solution and said liquid to a gallium phosphide surface via a polishing cloth.
Claim 5
Dependent Claim
34 words
The process of claim 3, wherein said solution and said liquid are applied at approximately equal rates of from about 1 to 10 ml/min per about 100 cm 2 of surface to be polished.
Claim 6
Dependent Claim
22 words
The process of claim 1, wherein said solution comprises about 1 part bleaching lye and from about 1 to 6 parts water.
Claim 7
Dependent Claim
24 words
The process of claim 5, wherein said buffering components are selected from the group consisting of hydrogen carbonate, hydrogen phosphate and a combination thereof.
References Cited (Backward Citations)
US3775201A
Cited
US4043861A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-15 | 1987-11-14 | 1988-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-15 | 1991-11-14 | 1992-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-15 | 1995-11-14 | 1996-05-15 | $7700.00 | Window Closed / Lapsed |