Patent US4547073A successfully refreshed from Google Patents.
US4547073A
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Surface examining apparatus and method
Assignee: Panasonic Holdings Corp
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Filing: 1982-02-11
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Granted: 1985-10-15
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Expires: 2002-02-11
Abstract
Abstract The surface of a polished semiconductor wafer is examined by an apparatus comprising a light source, a first optical means for converging the light to a parallel light and projecting it onto the surface to be examined and a second optical means for converging the light reflected by the surface and projecting it onto a light receiving screen. If the surface has a defect, such as a crystal imperfection, the surface forms a very slight recess or wave, for example, having a sub-micron depth and having an opening diameter of several mm. When such surface is examined by the above-mentioned apparatus, specific shading patterns, lines, stripes or dots are projected on the light-receiving screen, thereby making detection of wafer defects easy and even subject to automation.
Inventors
- 👤 Koichi Kugimiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:07
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/9501; G01N21/8851; G01N2021/8887; G01N2021/889; G01N21/8803
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
87 words
A surface examining apparatus, comprising: a substantially point light source for emitting light rays, an image-receiving means for receiving images, first optical means for converging said rays and for making them impinge as evenly distributed rays on a surface to be examined, and second optical means for converging rays reflected from said surface and for projecting said converged reflected rays substantially undiminished to said image-receiving means, said second optical means projecting an image to said image-receiving means constituting a defocussed image of said surface to be examined.
Claim 2
Dependent Claim
87 words
A surface examining apparatus, comprising: a substantially point light source for emitting light rays, an image-receiving means for receiving images, first optical means for converging said rays and for making them impinge as evenly distributed rays on a surface to be examined, and second optical means for converging rays reflected from said surface and for projecting said converged reflected rays substantially undiminished to said image-receiving means, said second optical means projecting an image to said image-receiving means constituting a defocussed image of said surface to be examined.
Claim 3
Dependent Claim
18 words
A surface examining apparatus in accordance with claim 1, wherein said second optical means comprises a convex lens.
Claim 4
Dependent Claim
25 words
A surface examining apparatus in accordance with claim 1, wherein said first optical means and said second optical means commonly comprise a single convex lens.
Claim 5
Dependent Claim
29 words
A surface examining apparatus in accordance with claim 1, wherein said first optical means and said second optical means comprises at least in one part thereof a half mirror.
Claim 6
Dependent Claim
29 words
A surface examining apparatus in accordance with claim 1, wherein said first optical means and said second optical means comprises at least in one part thereof a concave mirror.
Claim 7
Dependent Claim
16 words
A surface examining apparatus in accordance with claim 1, wherein, said image-receiving means is a camera.
Claim 8
Dependent Claim
38 words
A surface examining apparatus in accordance with claim 1, wherein, said first optical means comprises a ray condenser lens and a large convergence lens and said second optical means comprises said large convergence lens and another convergence lens.
Claim 9
Dependent Claim
89 words
A surface examining apparatus, comprising: a substantially point light source for emitting light rays, an image-receiving means for receiving images, first optical means for converging said rays and for making them impinge as evenly distributed rays on a surface of a semiconductor wafer, and second optical means for converging rays reflected from said surface and for projecting said converged reflected rays substantially undiminished to said image-receiving means, said second optical means projecting an image to said image-receiving means constituting a defocussed image of said surface of said semiconductor wafer.
Claim 10
Dependent Claim
89 words
A surface examining apparatus, comprising: a substantially point light source for emitting light rays, an image-receiving means for receiving images, first optical means for converging said rays and for making them impinge as evenly distributed rays on a surface of a semiconductor wafer, and second optical means for converging rays reflected from said surface and for projecting said converged reflected rays substantially undiminished to said image-receiving means, said second optical means projecting an image to said image-receiving means constituting a defocussed image of said surface of said semiconductor wafer.
Claim 11
Dependent Claim
18 words
A surface examining apparatus in accordance with claim 8, wherein, said second optical means comprises a convex lens.
Claim 12
Dependent Claim
25 words
A surface examining apparatus in accordance with claim 8, wherein said first optical means and said second optical means commonly comprise a single convex lens.
Claim 13
Dependent Claim
29 words
A surface examining apparatus in accordance with claim 8, wherein said first optical means and said second optical means comprises at least in one part thereof a half mirror.
Claim 14
Dependent Claim
29 words
A surface examining apparatus in accordance with claim 8, wherein said first optical means and said second optical means comprises at least in one part thereof a concave mirror.
Claim 15
Dependent Claim
16 words
A surface examining apparatus in accordance with claim 8, wherein said image-receiving means is a camera.
Claim 16
Dependent Claim
38 words
A surface examining apparatus in accordance with claim 8, wherein said first optical means comprises a ray condensor lens and a large convergence lens and said second optical means comprises said large convergence lens and another convergence lens.
Claim 17
Independent Claim
81 words
A method for examining a surface, comprising the steps of: shining light rays from a substantially point light source, making said rays impinge on a surface to be examined, and reflect therefrom, converging the rays reflected from said surface and projecting them substantially undiminished onto an image-receiving means to form a defocussed image with respect to said surface to be examined, and obtaining a shading pattern in said defocussed image which corresponds to an unevenness on said surface to be examined.
Claim 18
Independent Claim
81 words
A method for examining a surface, comprising the steps of: shining light rays from a substantially point light source, making said rays impinge on a surface to be examined, and reflect therefrom, converging the rays reflected from said surface and projecting them substantially undiminished onto an image-receiving means to form a defocussed image with respect to said surface to be examined, and obtaining a shading pattern in said defocussed image which corresponds to an unevenness on said surface to be examined.
Claim 19
Dependent Claim
48 words
A method for examining a surface in accordance with claim 15, wherein said impinging of said light rays on said surface is made by means of a first convex lens, and said converging and projecting of said reflected rays is made by means of a second convex lens.
Claim 20
Dependent Claim
39 words
A method for examining a surface in accordance with claim 15, wherein said impinging of said light rays on said surface and said converging and projecting of said reflected rays are made by means of a common convex lens.
Claim 21
Dependent Claim
20 words
A method for examining a surface in accordance with claim 15, wherein said impinging is made via a half mirror.
Claim 22
Dependent Claim
29 words
A method for examining a surface in accordance with claim 15, wherein said projecting of said reflected rays is made to a camera disposed as said image receiving means.
Claim 23
Dependent Claim
67 words
A method for examining a surface in accordance with claim 15, wherein said shining of said light rays is made by means of a condenser lens, said impinging of said aligned rays on said surface to be examined is made by means of a large diameter convex lens, said projecting of said image is made by means of said large diameter lens and an additional convergence lens.
Claim 24
Independent Claim
84 words
A method for examining a surface, comprising the steps of: shining light rays from a substantially point light source; making said rays impinge on a surface of a semiconductor wafer, and reflect therefrom, converging the rays reflected from said surface and projecting them substantially undiminished onto an image-receiving means to form a defocussed image with respect to said surface of a semiconductor wafer, and obtaining a shading pattern in said defocussed image which corresponds to an unevenness on said surface of said semiconductor wafer.
Claim 25
Independent Claim
84 words
A method for examining a surface, comprising the steps of: shining light rays from a substantially point light source; making said rays impinge on a surface of a semiconductor wafer, and reflect therefrom, converging the rays reflected from said surface and projecting them substantially undiminished onto an image-receiving means to form a defocussed image with respect to said surface of a semiconductor wafer, and obtaining a shading pattern in said defocussed image which corresponds to an unevenness on said surface of said semiconductor wafer.
Claim 26
Dependent Claim
48 words
A method for examining a surface in accordance with claim 21, wherein said impinging of said light rays on said surface is made by means of a first convex lens, and said converging and projecting of said reflected rays is made by means of a second convex lens.
Claim 27
Dependent Claim
39 words
A method for examining a surface in accordance with claim 21, wherein said impinging of said light rays on said surface and said converging and projecting of said reflected rays are made by means of a common convex lens.
Claim 28
Dependent Claim
20 words
A method for examining a surface in accordance with claim 21, wherein said impinging is made via a half mirror.
Claim 29
Dependent Claim
29 words
A method for examining a surface in accordance with claim 21, wherein said projecting of said reflected rays is made to a camera disposed as said image receiving means.
Claim 30
Dependent Claim
68 words
A method for examining a surface in accordance with claim 21, wherein said shining of said light rays is made by means of a condenser lens, said impinging of said light rays on said surface of said semiconductor wafer is made by means of a large diameter convex lens, said projecting of said image is made by means of said large diameter lens and an additional convergence lens.
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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) | 1988-10-14 | 1989-04-15 | 1989-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-14 | 1993-04-15 | 1993-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-14 | 1997-04-15 | 1997-10-15 | $7700.00 | Window Closed / Lapsed |