Fourier spectrum method to determine dose-to-clear in a photoresist.

A Fourier spectrum method to determine the dose-to-clear in a photoresist is proposed. The frequency content of scanning electron microscope resist images is used to determine whether the resist has been dissolved. Using this method, the dose to clear the resist is calculated automatically instead of via visual inspection, a method in which operator influence can affect the result. (C) 2014 Optical Society of America