Shape distortion of diffractive optical elements, directly written with electron beam lithography

It has previously been shown that the relief depth can be accurately adjusted by repeated development. The present authors used repeated development to study the relief shape as a function of development time for a blazed grating structure exposed in a thick, approximately 8 mu m, resist layer. The shape was obtained from measured diffraction data. This shape determining method appears to have a better accuracy than stylus measurements.<
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