Patent US3952776A successfully refreshed from Google Patents.
Patent EP0306275A2 successfully refreshed from Google Patents.
EP0306275A2
Expired / Lapsed
EP
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Photoelectron image projection apparatus
Assignee: Fujitsu Ltd
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Filing: 1988-08-31
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Granted: —
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Expires: 2008-08-31
Abstract
Abstract A photoelectron image projection apparatus has a device (30, 50) for detecting an image of a pattern of a mask (4) within a predetermined projection region of the mask. An image signal describing the detected image is compared with a reference image signal which is known from the pattern of the mask, and a defect in the projection pattern is detected when the two compared image signals differ.
Inventors
- 👤 Akio Yamada
- 👤 Hiroshi Yasuda
- 👤 Kiichi Sakamoto
- 👤 Jinko Kudo
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 03:46
CPC Classifications
G; G03; G03F; G03F9/00; G03F7/00; G03F7/26; H; H01; H01J; H01J37/00; H01J37/30; H10; H10P; H10P14/00; H10P14/60; H10P14/61; H01J2237/00; H01J2237/26; H01J2237/28; H01J2237/2813; H01J2237/2817; H01J2237/30; H01J2237/317; H01J2237/3175; H01J2237/31777; H01J2237/31779; H01J2237/31793; H01J2237/31794
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
228 words
A photoelectron image projection apparatus for projecting an image of a pattern of a mask (4) which has a photoelectric layer (4c) onto a wafer (2) by releasing photoelectrons (E) from the mask, said photoelectron image projection apparatus comprising a holder (5, 23) for holding the mask, and a projection chamber (1) in which the image of the pattern of the mask is projected onto the wafer by irradiating a light on the mask and releasing the photoelectrons from the mask, characterized in that there are provided: a light source (28, 8) for emitting a light (L); electron beam detector means (30, 50) for detecting a projection pattern within a predetermined projection region based on photoelectrons released and received from the mask (4) caused by an irradiation of the light from said light source on an arbitrary portion (141-144, 4n) of the mask corresponding to the predetermined projection region and for outputting an image signal describing the detected projection pattern before the projection is carried out with respect to the wafer in said projection chamber (1); and defect detector means (41) for comparing the image signal from said electron beam detector means and a reference image signal and for detecting a defect in the projection pattern when the two compared image signals differ, said reference image signal describing a regular projection pattern of the mask having no defect.
Claim 2
Dependent Claim
228 words
A photoelectron image projection apparatus for projecting an image of a pattern of a mask (4) which has a photoelectric layer (4c) onto a wafer (2) by releasing photoelectrons (E) from the mask, said photoelectron image projection apparatus comprising a holder (5, 23) for holding the mask, and a projection chamber (1) in which the image of the pattern of the mask is projected onto the wafer by irradiating a light on the mask and releasing the photoelectrons from the mask, characterized in that there are provided: a light source (28, 8) for emitting a light (L); electron beam detector means (30, 50) for detecting a projection pattern within a predetermined projection region based on photoelectrons released and received from the mask (4) caused by an irradiation of the light from said light source on an arbitrary portion (141-144, 4n) of the mask corresponding to the predetermined projection region and for outputting an image signal describing the detected projection pattern before the projection is carried out with respect to the wafer in said projection chamber (1); and defect detector means (41) for comparing the image signal from said electron beam detector means and a reference image signal and for detecting a defect in the projection pattern when the two compared image signals differ, said reference image signal describing a regular projection pattern of the mask having no defect.
Claim 3
Dependent Claim
37 words
A photoelectron image projection apparatus as claimed in claim 1, characterized in that said electron beam detector means has a two-dimensional electron beam detector (30, 50) for detecting a photoelectron intensity distribution within the predetermined projection region.
Claim 4
Dependent Claim
66 words
A photoelectron image projection apparatus as claimed in claim 2, characterized in that said two-dimensional electron beam detector includes a fluorescent plate (31, 51) for receiving the photoelectrons released from the mask caused by the irradiation of the light from said light source on the arbitrary portion of the mask, and a television camera (32, 52) for picking up an image displayed by said fluorescent plate.
Claim 5
Dependent Claim
35 words
A photoelectron image projection apparatus as claimed in claim 3, characterized in that said two-dimensional electron beam detector further includes a light metal film (34, 54) provided between said light source and said fluorescent plate.
Claim 6
Dependent Claim
46 words
A photoelectron image projection apparatus as claimed in claim 3 or 4, characterized in that said two-dimensional electron beam detector further includes a lens system (33, 53) provided between said fluorescent plate and said television camera for optically coupling said fluorescent plate and said television camera.
Claim 7
Dependent Claim
40 words
A photoelectron image projection apparatus as claimed in any of claims 3 to 5, characterized in that said two-dimensional electron beam detector further includes a two-dimensional electron beam multiplier (35, 55) provided between said light source and said fluorescent plate.
Claim 8
Dependent Claim
72 words
A photoelectron image projection apparatus as claimed in claim 2, characterized in that said two-dimensional electron beam detector includes a two-dimensional electron beam multiplier (35, 55) for receiving the photoelectrons released from the mask caused by the irradiation of the light from said light source on the arbitrary portion of the mask, and a two-dimensional charge coupled device (36, 56) for picking up an image received through said two-dimensional electron beam multiplier.
Claim 9
Dependent Claim
43 words
A photoelectron image projection apparatus as claimed in any of claims 1 to 7, characterized in that said arbitrary portion (141-144) of the mask corresponds to one semiconductor chip, said mask having a plurality of portions (141-144) respectively corresponding to one semiconductor chip.
Claim 10
Dependent Claim
85 words
A photoelectron image projection apparatus as claimed in any of claims 1 to 8, characterized in that there is further provided a movable stage (3A) for holding both the wafer and said electron beam detector means inside said projection chamber, said movable stage having a first position where said electron beam detector means confronts the mask when detecting the defect in the projection pattern and having a second position where the wafer confronts the mask when carrying out the projection with respect to the wafer.
Claim 11
Dependent Claim
34 words
A photoelectron image projection apparatus as claimed in any of claims 1 to 9, characterized in that said light source (8, 28) is used in common for the projection with respect to the wafer.
Claim 12
Dependent Claim
66 words
A photoelectron image projection apparatus as claimed in any of claims 1 to 10, characterized in that said arbitrary portion (141-144) of the mask corresponds to one semiconductor chip, said mask having a plurality of portions (141-144) respectively corresponding to one semiconductor chip, said holder (5, 23) being movable, so that a defect can be detected in each of said plurality of portions of the mask.
Claim 13
Dependent Claim
44 words
A photoelectron image projection apparatus as claimed in any of claims 1 to 11, characterized in that there is further provided a deposition chamber (11) connected to said projection chamber, said deposition chamber having means (12) for depositing the photoelectric layer of the mask.
Claim 14
Dependent Claim
57 words
A photoelectron image projection apparatus as claimed in claim 1, characterized in that there is further provided enlarging means (26, 27) for enlarging the projection pattern of the arbitrary portion (4n) of the mask within the predetermined projection region, said electron beam detector means having a two-dimensional electron beam detector (30) for detecting the enlarged projection pattern.
Claim 15
Dependent Claim
65 words
A photoelectron image projection apparatus as claimed in claim 13, characterized in that said two-dimensional electron beam detector (30) includes a fluorescent plate (31) for receiving the photoelectrons released from the mask caused by the irradiation of the light from said light source on the arbitrary portion of the mask, and a television camera (32) for picking up an image displayed by said fluorescent plate.
Claim 16
Dependent Claim
37 words
A photoelectron image projection apparatus as claimed in claim 13 or 14, characterized in that said two-dimensional electron beam detector (30) further includes a light metal film (34) provided between said light source and said fluorescent plate.
Claim 17
Dependent Claim
48 words
A photoelectron image projection apparatus as claimed in any of claims 13 to 15, characterized in that said two-dimensional electron beam detector (30) further includes a lens system (33) provided between said fluorescent plate and said television camera for optically coupling said fluorescent plate and said television camera.
Claim 18
Dependent Claim
40 words
A photoelectron image projection apparatus as claimed in any of claims 13 to 16, characterized in that said two-dimensional electron beam detector (30) further includes a two-dimensional electron beam multiplier (35) provided between said light source and said fluorescent plate.
Claim 19
Dependent Claim
71 words
A photoelectron image projection apparatus as claimed in claim 13, characterized in that said two-dimensional electron beam detector (30) includes a two-dimensional electron beam multiplier (35) for receiving the photoelectrons released from the mask caused by the irradiation of the light from said light source on the arbitrary portion of the mask, and a two-dimensional charge coupled device (36) for picking up an image received through said two-dimensional electron beam multiplier.
Claim 20
Dependent Claim
45 words
A photoelectron image projection apparatus as claimed in any of claims 13 to 18, characterized in that said arbitrary portion (4n) of the mask corresponds to a portion of one semiconductor chip, said mask having a plurality of portions respectively amounting to one semiconductor chip.
Claim 21
Dependent Claim
54 words
A photoelectron image projection apparatus as claimed in claim 19, characterized in that said holder (5, 23) is movable and moves the mask to successively change the portion which becomes the subject of the projection, thereby projecting the enlarged image corresponding to an entire projection region of the mask corresponding to one semiconductor chip.
Claim 22
Dependent Claim
44 words
A photoelectron image projection apparatus as claimed in any of claims 13 to 20, characterized in that said electron beam detector means (30) detects the projection pattern within the predetermined projection region inside a pattern detecting chamber (21) which connects to said projection chamber.
Claim 23
Dependent Claim
40 words
A photoelectron image projection apparatus as claimed in claim 21, characterized in that there is further provided a deposition chamber (11) connected to said projection chamber, said deposition chamber having means (12) for depositing the photoelectric layer of the mask.
Claim 24
Dependent Claim
28 words
A photoelectron image projection apparatus as claimed in claim 22, characterized in that said pattern detecting chamber (21) is provided between said projection chamber and said deposition chamber.
Claim 25
Dependent Claim
36 words
A photoelectron image projection apparatus as claimed in any of claims 13 to 22, characterized in that said electron beam detector means (30) detects the projection pattern within the predetermined projection region inside said projection chamber.
References Cited (Backward Citations)
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