US 2010/0134615 A1Published application

Shape measurement apparatus and shape measurement method

AssigneeKobelco Research Institute, Inc.

InventorsMasaru Akamatsu, Hidehisa Hashizume, Yasuhide Nakai

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Abstract

To provide a shape measurement apparatus and a shape measurement method with which it is possible to perform a shape measurement, when a shape of an end surface of a disk-shaped semiconductor wafer or the like is measured on the basis of a projection image thereof, without receiving an influence of a contaminant on the end surface. With a rotation supporting mechanism 9 supporting a wafer 1, the wafer 1 is supported in a range from a first supporting position rotated by +δ with respect to a predetermined reference supporting position to a second supporting position rotated by −δ degrees at two or more supporting positions including the first supporting position and the second supporting position, a projection image of the end surface of the wafer 1 supported at the respective supporting positions is picked up by an image sensor 7, an index value of an end surface value is calculated for each of a plurality of obtained projection images, a selection of one representative value based on the plurality of calculated index values or a calculation of one aggregate value is performed, and a measurement value for the shape of the end surface of the wafer 1 corresponding to the reference supporting position is derived. At that time, when a radius of the wafer 1 and a chamfer width are set as r and k, δ≧cos−1 ((r−k)/r) is desirably satisfied.

Claims16

Dependent claims

A shape measurement apparatus comprising:

light transmission means configured to transmit light to a chamfer processed end part of a disk-shaped measurement target from a direction substantially parallel to respective front and rear surfaces of the measurement target;
image pickup means configured to pick up a projection image of an end surface of the measurement target from a direction opposite to the light transmitting direction;
a rotation supporting mechanism configured to rotatably support the measurement target in a circumferential direction thereof;
rotation control means configured to support the measurement target by the rotation supporting mechanism in a range from a first supporting position rotated by a predetermined first set angle with respect to a predetermined reference supporting position to a second supporting position rotated by a predetermined second set angle having an opposite positive or negative sign with respect to the first set angle at two or more supporting positions including the first supporting position and the second supporting position;
image pickup control means configured to pick up by the image pickup means the projection image of the end surface of the measurement target supported by the rotation control means at the two or more supporting positions;
index value calculation means configured to calculate an index value of an end surface shape by executing a previously set image processing for each of a plurality of projection images obtained through a processing by the image pickup control means;
and
measurement value derivation means configured to derivate a measurement value for the shape of the end surface of the measurement target corresponding to the reference supporting position by selecting one representative value based on the plurality of index values calculated by the index value calculation means or calculating one aggregate value while following a previously set rule.

5 more elements

A shape measurement method comprising:

transmitting light by light transmission means to a chamfer processed end part of a disk-shaped measurement target from a direction substantially parallel to respective front and rear surfaces of the measurement target;
picking up a projection image of an end surface of the measurement target by image pickup means from a direction opposite to the light transmitting direction;
supporting the measurement target by a rotation supporting mechanism rotatably supporting the measurement target in a circumferential direction thereof in a range from a first supporting position rotated by a predetermined first set angle with respect to a predetermined reference supporting position to a second supporting position rotated by a predetermined second set angle having an opposite positive or negative sign with respect to the first set angle at two or more supporting positions including the first supporting position and the second supporting position;
picking up by the image pickup means a plurality of projection images of the end surface of the measurement target supported at the respective supporting positions;
recording image pickup data in predetermined storage means;
calculating a plurality of index values of an end surface shape by executing a previously set image processing by predetermined computation means for each of the plurality of projection images;
and
executing a processing of deriving a measurement value for the shape of the end surface of the measurement target corresponding to the reference supporting position by predetermined computation means by selecting one representative value based on the plurality of index values calculated by the index value calculation means or calculating one aggregate value while following a previously set rule.

5 more elements

Dependencies are inferred from the claim text.