Patent US4439268A successfully refreshed from Google Patents.
US4439268A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Orientation of INP substrate wafers
Assignee: AT&T Inc
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Filing: 1983-09-06
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Granted: 1984-03-27
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Expires: 2003-09-06
Abstract
Abstract A method for determining crystallographic orientation of an InP substrate wafer includes the steps of immersing at least a portion of the substrate wafer in a chemical etchant for a predetermined amount of time to expose features having a predetermined shape and designating a particular crystallographic direction on the substrate wafer in accordance with relative positions of features on the portion of the substrate wafer.
Inventors
- 👤 Larry A. Coldren
- 👤 Lawrence W. Stulz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:14
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/12; H10P90/14; H10D; H10D62/00; H10D62/10; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/646; H10P50/648; H10P90/126; Y; Y10; Y10S; Y10S438/00; Y10S438/973
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
95 words
A method of determining the orientation of a (100) InP substrate wafer, the method comprising the steps of contacting at least a portion of the substrate wafer with a chemical etchant to expose a plurality of features having a predetermined shape on the portion of substrate wafer, and designating a crystallographic direction on the substrate wafer in accordance with the orientation of the features on the portion of the substrate wafer, the method being characterized in that the portion of the substrate wafer includes at least one surface being substantially perpendicular to the (100) plane.
Claim 2
Independent Claim
95 words
A method of determining the orientation of a (100) InP substrate wafer, the method comprising the steps of contacting at least a portion of the substrate wafer with a chemical etchant to expose a plurality of features having a predetermined shape on the portion of substrate wafer, and designating a crystallographic direction on the substrate wafer in accordance with the orientation of the features on the portion of the substrate wafer, the method being characterized in that the portion of the substrate wafer includes at least one surface being substantially perpendicular to the (100) plane.
Claim 3
Dependent Claim
17 words
The method as defined in claim 1 wherein the at least one surface is a cleavage plane.
Claim 4
Dependent Claim
15 words
The method as defined in claim 1 wherein the chemical etchant is a preferential etchant.
Claim 5
Dependent Claim
14 words
The method as defined in claim 2 wherein the chemical etchant is concentrated HCl.
Claim 6
Dependent Claim
16 words
The method as defined in claim 3 wherein the predetermined shape of the feature is triangular.
Claim 7
Independent Claim
86 words
A method of determining the orientation of a (100) InP substrate wafer, the method characterized by the steps of cleaving at least a first surface substantially perpendicular to the (100) plane, contacting at least the first surface of the substrate wafer with a chemical etchant to expose a plurality of features having a predetermined shape on the portion of substrate wafer, and designating a crystallographic direction on the substrate wafer in accordance with the orientation of the features on the first surface of the substrate wafer.
Claim 8
Independent Claim
86 words
A method of determining the orientation of a (100) InP substrate wafer, the method characterized by the steps of cleaving at least a first surface substantially perpendicular to the (100) plane, contacting at least the first surface of the substrate wafer with a chemical etchant to expose a plurality of features having a predetermined shape on the portion of substrate wafer, and designating a crystallographic direction on the substrate wafer in accordance with the orientation of the features on the first surface of the substrate wafer.
Claim 9
Dependent Claim
15 words
The method as defined in claim 6 wherein the chemical etchant is a preferential etchant.
Claim 10
Dependent Claim
14 words
The method as defined in claim 7 wherein the chemical etchant is concentrated HCl.
Claim 11
Dependent Claim
16 words
The method as defined in claim 8 wherein the predetermined shape of the feature is triangular.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-27 | 1987-09-26 | 1988-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-27 | 1991-09-26 | 1992-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-27 | 1995-09-26 | 1996-03-27 | $7700.00 | Window Closed / Lapsed |