FINE-TUNED PROFILE SIMULATION OF HOLOGRAPHICALLY EXPOSED PHOTORESIST GRATINGS

The profiles of holographically exposed photoresist gratings are simul ated according to the state of the art obtained in microlithography. T he accuracy of the simulation depends on the accuracy of the developme nt rate R of the photoresist, which is a function of the normalised un exposed photoactive compound concentration or inhibitor concentration M after exposure. It is shown that this development rate R has to be f ine tuned by using experimentally obtained photoresist profiles in ord er to obtain the required accuracy. With fine tuned development rate, a very good agreement between theory and experiment can be obtained in the case of holographically exposed photoresist gratings with periods in the range of 1 mu m The properties of the photoresist, of the deve lopment and of the optical set-up which are necessary for sinusoidal p hotoresist profiles are also discussed. (C) 1998 Elsevier Science B.V. All rights reserved.