EP0838679A2
Expired / Lapsed
EP
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Method and apparatus for inspecting high-precision patterns
Assignee: NEC Corp
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Filing: 1997-10-22
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Granted: —
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Expires: 2017-10-22
Abstract
Abstract A device and method for inspecting a test piece with a laser beam in which the laser beam is divided into plural beams, and each of the plural beams has an identification marker, such as a particular polarity or intensity. Each of the marked beams, scans a different portion of the test piece to reduce the time needed to inspect the test piece. <IMAGE>
Inventors
- 👤 Shingo Murakami
- 👤 Tsuyoshi Yamane
- 👤 Yukio Ogura
- 👤 Katsuhiko Nakatani
- 👤 Yoshiaki c/o Showa Optronics Co. Ltd. Aida
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 02:49
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/9501; G01N21/956; H; H10; H10P; H10P74/00; H10P74/20; H10P74/203
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
82 words
A method of inspecting a surface of a test piece
with a laser beam, comprising the steps of: dividing the laser beam into a plurality of laser beams; providing an identification marker in each of the
plurality of laser beams; scanning the surface of the test piece with the plurality
of marked laser beams;
providing an image of the surface of the test piece using at
least one of reflected and transmitted light for each of the
plurality of marked laser beams.
Claim 2
Dependent Claim
36 words
The method of claim 1, wherein said laser beam
branching step includes splitting said laser beam into two,
tilting the optical axis of one of the split laser beams, and
synthesizing the two split laser beams.
Claim 3
Dependent Claim
23 words
The method of claim 1, wherein said identification
marker is a different polarized state assigned to each of
said plurality of laser beams.
Claim 4
Dependent Claim
25 words
The method of claim 1, wherein said identification
marker is a variation in a light intensity assigned to each
of said plurality of laser beams.
Claim 5
Dependent Claim
13 words
The method of claim 1, wherein said laser beam has an
ultraviolet wavelength.
Claim 6
Dependent Claim
30 words
The method of claim 1, wherein the step of scanning
comprises the step of simultaneously scanning a different
portion of the test piece with each of the marked laser
beams.
Claim 7
Independent Claim
136 words
An apparatus for inspecting a surface of a test piece
with a laser beam, comprising: a source of a laser beam; means for dividing said laser beam into a plurality of
laser beams; means for assigning an identification marker to each of
said plurality of laser beams; means for radiating said plurality of marked laser beams
onto the surface of the test piece; means for detecting at least one of the light reflected
from the surface of the test piece and the light transmitted
through the surface of the test piece; and an image processing unit for identifying each of said
plurality of marked laser beams by said identification
markers and for detecting a defect in the surface of the
piece by obtaining an image of the surface of the test piece
from said detecting means.
Claim 8
Dependent Claim
51 words
The apparatus as claimed in claim 7, wherein said
dividing means includes a splitting means for splitting said
laser beam into two, an optical axis changing means for
tilting the optical axis of one of the two split laser beams,
and a synthesizing means for synthesizing said two split
laser beams.
Claim 9
Dependent Claim
18 words
The apparatus as claimed in claim 8, wherein said
optical axis changing means includes a wedge-shaped glass
plate.
Claim 10
Dependent Claim
76 words
The apparatus as claimed in claim 7, wherein said
dividing means is a plurality of unit laser beam branching
means provided in at least one of parallel and series
arrangements, said unit laser beam branching means including
one splitting means for splitting said laser beam into two,
one optical axis changing means for tilting the optical axis
of one of the two split laser beams, and one synthesizing
means for synthesizing said two split laser beams.
Claim 11
Dependent Claim
18 words
The apparatus as claimed in claim 10, wherein said
optical axis changing means includes a wedge-shaped glass
plate.
Claim 12
Dependent Claim
26 words
The apparatus as claimed in claim 7, wherein said
identification marker is a different polarized state assigned
to each of said plurality of divided laser beams.
Claim 13
Dependent Claim
28 words
The apparatus as claimed in claim 7, wherein said
identification marker is a variation in a light intensity
assigned to each of said plurality of divided laser beams.
Claim 14
Dependent Claim
57 words
The apparatus as claimed in claim 13, wherein said
identification marker assigning means comprises an ultrasonic
modulating means for analog modulation of each of said
plurality of divided laser beams to change a light intensity
thereof and a modulation signal generating means for outputting
a modulation signal to said ultrasonic modulating means
in a time division manner.
Claim 15
Dependent Claim
15 words
The apparatus as claimed in claim 7, wherein the
laser beam has an ultraviolet wavelength.
Claim 16
Dependent Claim
78 words
The apparatus as claimed in claim 7, wherein said
radiating means comprises: a focusing means for radiating a focusing laser beam of
wavelength different from the laser beam for focusing onto
the surface of the test piece; a focus position detecting means for detecting the
variance of focus position of the light reflected from the
test piece; and a focus position moving means for moving said focus
position based on a signal from said focus position detecting
means.
Claim 17
Dependent Claim
29 words
The apparatus as claimed in claim 16, wherein said
focus position detecting means comprising: a split detector; and a knife edge for cutting off half of the reflected
light.
Claim 18
Dependent Claim
39 words
The apparatus as claimed in claim 7, further
comprising an XY stage comprising an X stage movable only in
the X direction, a Y stage movable only in the Y direction,
and a stage only able to rotate.
References Cited (Backward Citations)
No citation records indexed.
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