Clearance measuring device and method for exposure
AssigneeSanei Giken Co., Ltd.
InventorsEiichi Miyake, Ken Miyake
Life of this patent
Estimating the term…
Abstract
A position of an image or shadow of a clearance measuring mark projected onto a plate with respect to a position of clearance measuring mark on a photomask is sensed as image data by a CCD camera and subjected to an image process by a processor. Based on a relative positional relationship between image or shadow of a clearance measuring mark and clearance measuring mark, the clearance between photomask and plate can be adjusted to a prescribed value by a clearance adjusting device. As a result, a clearance measuring device and method can be provided capable of accurately and inexpensively measuring the clearance between the plate and the photomask in the exposure apparatus.
Claims14
A clearance measuring device measuring a clearance between a photomask and a plate for adjusting said clearance between said photomask and said plate to a prescribed value in accordance with the measurement data in an exposure apparatus transferring a pattern on said photomask onto said plate by directing light to said plate through said photomask, said photomask having a clearance measuring mark in a prescribed position on a surface opposite to said plate, comprising:
- at least one light sensor for sensing an image or shadow of said clearance measuring mark projected on said plate by irradiating said clearance measuring mark and a region including said clearance measuring mark with light;
- calculating means calculating a clearance between said photomask and said plate based on a relative positional relationship between said clearance measuring mark and said image or said shadow of said clearance measuring mark;
- and
- clearance adjusting means for adjusting the clearance between said photomask and said plate to a prescribed value by relatively moving said photomask and said plate based on the calculation result from said calculating means.
A clearance measuring method using a photomask having a clearance measuring mark for measuring a clearance between said photomask and a plate and adjusting said clearance between said photomask and said plate to a prescribed value in an exposure apparatus directing a light to said plate through said photomask for transferring a pattern on said photomask onto said plate, wherein said clearance between said photomask and said plate is calculated based on a relative positional relationship between an image or shadow of said clearance measuring mark projected onto said plate and said clearance measuring mark by irradiating a region including said clearance measuring mark with light, and said photomask and said plate are relatively moved based on the calculation result, so that said clearance between said photomask and said plate is adjusted to a prescribed value.
Dependencies are inferred from the claim text.