Simple Method for Resist Critical Dimension Prediction

A simple calculation method which predicts resist critical dimension (CD) with high precision is proposed. To simplify the formalism, the image intensity profile and dissolution rate variation of the resist are approximated with a linear and an exponential function, respectively. And the three step development approximation, in which development is assumed to proceed only vertically in the first step, only horizontally with a varying development rate in the second step and also horizontally with a constant rate in the third step, is adopted. With these simplifications, the resist edge displacement is expressed with a primitive formula. This method is examined by comparing the experimental and calculated results, confirming the effectiveness of the method.