Mask for inspecting an exposure apparatus, a method of inspecting an exposure apparatus, and an exposure apparatus
AssigneeKabushiki Kaisha Toshiba
InventorKazuya Fukuhara
Life of this patent
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Abstract
To inspect the polarization state of light flux for exposure of an exposure apparatus, a mask for inspection is held at the photomask position. This mask for inspection comprises a polarizing element which is disposed in a light path of light flux forming an image of a light source and which can selectively transmit light flux with a plurality of polarization directions.
Claims20
A mask for inspecting an exposure apparatus in which a photomask is held at a position which is optically conjugated with an object to be exposed and light flux for exposure from a light source is projected via said photomask onto said object to be exposed, comprising:
- an optical system disposed between said light source and said position to form an image of said light source at said position;
- and
- a polarizing element disposed in a light path of light flux forming said image of said light source to selectively transmit light flux with a plurality of polarization-axis directions,
- wherein the mask is held at said position in place of the photomask to inspect a polarization state of the light flux for exposure of the exposure apparatus.
A method of inspecting an exposure apparatus which includes a light source generating light flux for exposure, a projection optical system projecting the light flux for exposure onto an object to be exposed, and a photomask with a mask pattern formed at a position which is optically conjugated by said projection optical system to said object to be exposed, the mask pattern being projected onto said object to be exposed, said method comprising:
- inserting between said light source and said position an optical system to form an image of said light source at said position,
- inserting a polarizer into a light path of light flux forming the light source image, and then
- projecting said light flux for exposure onto said object to be exposed via said optical system, said polarizer, and said projection optical system, with the polarization-axis direction of said polarizer being changed;
- and
- determining a polarization state of said light flux for exposure by comparing a light intensity distribution of said light flux for exposure on said object to be exposed, said light intensity distribution being different for each of said polarization-axis directions.
An exposure apparatus including:
- a light source generating light flux for exposure toward an object to be exposed;
- an object holding member holding said object to be exposed;
- a projection optical system projecting the light flux for exposure onto said object to be exposed;
- and
- a photomask holding member holding a photomask at a position which is optically conjugated by said projection optical system to said object to be exposed,
- said exposure apparatus comprising,
- a mask for inspection held on said photomask holding member in place of said photomask and determining a polarization state of said light flux for exposure, wherein
- the mask for inspection comprises:
- a an optical system located between said light source and said position to form an image of said light source at said position;
- and
- a polarizing element with a variable polarization-axis direction inserted in a light path of light flux forming said light source.
Dependencies are inferred from the claim text.