Standard Test Method for Distortion of Optical Lenses Used in Photomask Fabrication
|Publication Date:||1 January 1980|
1.1 This test method covers a means for measuring the distortion of optical systems used in the fabrication of photomasks for semiconductor device manufacturing. This test method is intended primarily for lenses used in step-and-repeat systems which operate within the extended visible wavelength region (300 to 700 nm).
1.2 This test method measures distortion in Cartesian coordinates.
NOTE 1--Distortion is commonly measured in polar coordinates by other methods and, in those methods, is given in radial and tangential components. This difference should be considered whenever results of the test method are compared with results from other test methods.
1.3 This test method depends directly on x and y coordinate measurements and requires access to a coordinate-measuring
1.4 This test method is primarily intended for in situ testing; that is, for lenses which are an integral part of the system used for fabricating photomasks.
NOTE 2--Alternative methods for the evaluation of lens distortion, such as those discussed by Washer et al., generally require removal of the optics from the system under test.
1.5 This standard does not purport to address the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For more specific hazard statements, see Section 9.