EP0119455A2
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EP
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Etching method and apparatus
Assignee: Hitachi Ltd
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Filing: 1984-02-13
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Granted: —
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Expires: 2004-02-13
Abstract
Abstract The present invention consists in an etching method and apparatus wherein an optical image, which is reflected from a region of a dicing stripe pattern on a substrate (15) to be etched such as a semiconductor wafer is focused by a projecting optical system (17,18) during selective etching, the focused pattern is converted into an image signal by an image detector (19), a change of contrast in the region of the dicing stripe pattern is found from the image signal, and an end of the etching is decided on the basis of the found change of contrast.
Inventors
- 👤 Toru Otsubo
- 👤 Susumu Aiuchi
- 👤 Takashi Kamimura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 11:58
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32917; H01J37/32935; H10; H10P; H10P50/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
97 words
An etching method, characterized by the step of focusing by a projecting optical system (17, 18) an optical image, which is reflected from a region of a dicing stripe pattern on a substrate (15) to be etched during selective etching, the step of converting the focused pattern into an image signal by an image detector (19), the step of finding a change of contrast in the region of the dicing stripe pattern on the basis of the image signal, and the step of deciding a state of etching on the basis of the found change of contrast.
Claim 2
Dependent Claim
97 words
An etching method, characterized by the step of focusing by a projecting optical system (17, 18) an optical image, which is reflected from a region of a dicing stripe pattern on a substrate (15) to be etched during selective etching, the step of converting the focused pattern into an image signal by an image detector (19), the step of finding a change of contrast in the region of the dicing stripe pattern on the basis of the image signal, and the step of deciding a state of etching on the basis of the found change of contrast.
Claim 3
Dependent Claim
25 words
An etching method according to claim 1, characterized in that said substrate (15) to be etched is a semiconductor wafer for forming a semiconductor circuit.
Claim 4
Dependent Claim
36 words
An etching method according to claim 2, characterized in that said semiconductor wafer has underlying Si0 2 , which is overlaid with an Al layer, which is further overlaid with a resist for the selective etching.
Claim 5
Dependent Claim
24 words
An etching method according to claim 1, 2 or 3, characterized in that the etching state to be-decided is an end of the etching.
Claim 6
Dependent Claim
119 words
An etching apparatus, characterized by a) an etching processing chamber (12), in which a substrate (15) to be etched is received, b) illumination means (21, 22, 23; 24, 25, 26, 27) to illuminate said substrate (15) to be etched, c) a projecting optical system (17, 18), which focuses an optical image reflected from a region of a dicing stripe pattern on said substrate (15) to be etched, d) an image detector (19), which converts the pattern focused by said projecting optical system, into an image signal, and e) decision means (20) to decide an etching state on the basis of the fact that a change of the image signal obtained from said image detector has exceeded a predetermined value.
Claim 7
Dependent Claim
119 words
An etching apparatus, characterized by a) an etching processing chamber (12), in which a substrate (15) to be etched is received, b) illumination means (21, 22, 23; 24, 25, 26, 27) to illuminate said substrate (15) to be etched, c) a projecting optical system (17, 18), which focuses an optical image reflected from a region of a dicing stripe pattern on said substrate (15) to be etched, d) an image detector (19), which converts the pattern focused by said projecting optical system, into an image signal, and e) decision means (20) to decide an etching state on the basis of the fact that a change of the image signal obtained from said image detector has exceeded a predetermined value.
Claim 8
Dependent Claim
27 words
An etching apparatus according to claim 5, characterized in that an optic axis of said projecting optical system is perpendicular to said substrate (15) to be etched.
Claim 9
Dependent Claim
72 words
An etching apparatus according to claim 6, characterized in that said decision means (20) is constructed of a band-pass filter (33), which removes high frequency and low frequency components of the image signal obtained from said image detector (19), and comparison means (34) to detect that a part of a signal obtained from said band-pass filter (33), corresponding to the dicing stripe pattern, has exceeded a predetermined threshold value set in advance.
Claim 10
Dependent Claim
100 words
An etching apparatus according to claim 6, characterized in that said decision means (20) is constructed of a binary coded picture element circuit (41), which turns the image signal obtained from said image detector (19), into binary coded picture elements with a predetermined threshold value, black/white proportion calculation means (44) to calculate a proportion of black/white on the basis of the binary coded picture element signal obtained from said binary coded picture element circuit (41), and comparison means to detect the fact that the proportion of black/white obtained by said black/ white proportion calculation means has exceeded a predetermined value.
Claim 11
Dependent Claim
42 words
An etching apparatus according to claim 7 or 8, characterized in that said illumination means (21, 22, 23) expands a laser beam of specified wavelengths and projects the expanded beam on said substrate (15) to be etched in a direction oblique thereto.
Claim 12
Dependent Claim
42 words
An etching apparatus according to claim 7 or 8, characterized in that said illumination means (21, 22, 23) projects light of specified wavelengts on said substrate (15) to be etched in a direction perpendicular thereto by the use of a filter (26).
References Cited (Backward Citations)
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