US5137544A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stress-free chemo-mechanical polishing agent for II-VI compound semiconductor single crystals and method of polishing
Assignee: Boeing Co
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Filing: 1990-04-10
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Granted: 1992-08-11
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Expires: 2010-04-10
Abstract
Abstract In the present invention Stress-Free Chemo-Mechanical Polishing Agent For II-VI Compound Semiconductor Single Crystals And Method Of Polishing, a II-VI compound semiconductor single crystal wafer is polished smooth to within 50 angstroms by using a mixture of water, colloidal silica and bleach including sodium hypochlorite applied under time and pressure control to achieve chemo-mechanical polishing. Many such compound crystals are not susceptible to polishing by prior art methods.
Inventors
- 👤 Daniel Medellin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:50
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/04; B24B37/07; B24B37/10; B24B37/105; B24B37/107; B24D; B24D3/00; B24D3/02; B24D3/04; B24D3/14
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
37 words
A substantially stress-free chemo-mechanical polishing agent for Group II-VI compound crystal semiconductors, comprising in combination: a mixture of water, colloidal silica and sodium hypochlorite wherein the volume of silica is many times the volume of sodium hypochlorite.
Claim 2
Dependent Claim
37 words
A substantially stress-free chemo-mechanical polishing agent for Group II-VI compound crystal semiconductors, comprising in combination: a mixture of water, colloidal silica and sodium hypochlorite wherein the volume of silica is many times the volume of sodium hypochlorite.
Claim 3
Dependent Claim
28 words
The agent of claim 1, wherein: the volumetric ratio range for said mixture is as follows: water 35-50 colloidal silica 10-35 bleach 1-5 including approximately 5.25% sodium hypochlorite.
Claim 4
Dependent Claim
40 words
The agent of claim 2, wherein: the semiconductor comprises mercury cadmium telluride and the preferred ratio by volume of the agent components is: water (35) colloidal silica (35) bleach 5 including approximately 5.25% sodium hypochlorite and the rest inert materials.
Claim 5
Dependent Claim
54 words
A substantially stress-free chemo-mechanical polishing agent for Group II-VI compound semiconductor single crystal thin films capable of achieving surface smoothness of the thin film to less than fifty angstroms, comprising in combination: an aqueous solution of colloidal silica and sodium hypochlorite wherein the volume of silica is many times the volume of sodium hypochlorite.
Claim 6
Dependent Claim
54 words
A substantially stress-free chemo-mechanical polishing agent for Group II-VI compound semiconductor single crystal thin films capable of achieving surface smoothness of the thin film to less than fifty angstroms, comprising in combination: an aqueous solution of colloidal silica and sodium hypochlorite wherein the volume of silica is many times the volume of sodium hypochlorite.
Claim 7
Dependent Claim
27 words
The polishing agent of claim 4, wherein: the volumetric ratio range for said solution is: water 35-50 colloidal silica 10-35 bleach 1-5 including about 5.25% sodium hypochlorite.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-11 | 1996-02-10 | 1996-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-11 | 2000-02-10 | 2000-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-11 | 2004-02-10 | 2004-08-11 | $7700.00 | Window Closed / Lapsed |