US3782836A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface irregularity analyzing method
Assignee: Texas Instruments Inc
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Filing: 1971-11-11
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Granted: 1974-01-01
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Expires: 1991-11-11
Abstract
Abstract A surface irregularity analyzing system includes structure for directing light toward a surface in a direction having a certain angular relationship to the surface. If the light strikes irregularities in the surface, it is reflected in a direction having an angular relationship to the surface other than equal and opposite the incident direction. The amount of light reflected from irregularities in the surface is determined, either photographically or photoelectrically, to provide an analysis of irregularities in the surface.
Inventors
- 👤 C Fey
- 👤 S Watelski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:32
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/30; G01B11/303; G01N; G01N21/00; G01N21/84; G01N21/88
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
108 words
A method of detecting defects in the crystallographic structure of a predetermined plane of a material sample comprising: a. exposing a sample surface extending in a plane parallel to a given crystallographic plane of the material to a dislocation etch solution to produce etch pits having plane wall surfaces lying in crystallographic planes other than the plane of said surface; b. directing light to said surface from a direction having an angular relationship to said surface which is less than 90*; and c. detecting light reflected directly from a wall surface of said etch pits as an indication of the number and location of defects on said surface.
Claim 2
Independent Claim
108 words
A method of detecting defects in the crystallographic structure of a predetermined plane of a material sample comprising: a. exposing a sample surface extending in a plane parallel to a given crystallographic plane of the material to a dislocation etch solution to produce etch pits having plane wall surfaces lying in crystallographic planes other than the plane of said surface; b. directing light to said surface from a direction having an angular relationship to said surface which is less than 90*; and c. detecting light reflected directly from a wall surface of said etch pits as an indication of the number and location of defects on said surface.
Claim 3
Dependent Claim
27 words
The method defined in claim 1 including the further step of providing a measure of the quantity of light reflected directly from said etch pit wall surfaces.
Claim 4
Dependent Claim
41 words
The method defined in claim 1 further including the step of recording the location of said reflected light from each of said etch pits on said surface to provide a record of the number and location of defects on said surface.
Claim 5
Independent Claim
130 words
A method of detecting defects in the crystallographic structure of a slice of semiconductor material comprising: a. exposing a surface of said slice extending in a plane parallel to a given crystallographic plane thereof to a disclocation etch solution to produce in said surface etch pits at defect locations having wall surfaces lying in crystallographic planes other than said surface plane; b. illuminating said etch pits from a plurality of collimated light sources so arranged that light from one of said sources reflected from etch pit walls lying in one crystallographic plane is reflected in the same direction as light from another of said sources reflected from etch pit walls lying in a different crystallographic plane, and detecting the light reflected directly from the wall surfaces of said etch pits.
Claim 6
Independent Claim
130 words
A method of detecting defects in the crystallographic structure of a slice of semiconductor material comprising: a. exposing a surface of said slice extending in a plane parallel to a given crystallographic plane thereof to a disclocation etch solution to produce in said surface etch pits at defect locations having wall surfaces lying in crystallographic planes other than said surface plane; b. illuminating said etch pits from a plurality of collimated light sources so arranged that light from one of said sources reflected from etch pit walls lying in one crystallographic plane is reflected in the same direction as light from another of said sources reflected from etch pit walls lying in a different crystallographic plane, and detecting the light reflected directly from the wall surfaces of said etch pits.
Claim 7
Dependent Claim
28 words
The method as defined in claim 4 further comprising the step of providing a measure of the total amount of light reflected directly from said etch pit walls.
Claim 8
Dependent Claim
18 words
The method defined in claim 5 including the further step of recording said measure of light so reflected.
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) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |