Method of figuring exposure energy

Abstract

A method of figuring an exposure energy. A required exposure energy is calculated according to a critical dimension (CD) of an exposing layer. A first CD deviation is obtained from a layer before the exposing layer. From the first CD deviation, a first energy compensation is calculated. Whether the deviation of photoresist sensitivity of two sequential batches is less than 1% is checked. If the deviation of photoresist sensitivity of two sequential batches is less than 1%, a sum of the required exposure energy and the first energy compensation is the exposure energy applied to the exposing layer. Otherwise, a second CD deviation is commutated according to the deviation of photoresist sensitivity of two sequential batches. A second energy compensation is then obtained from the second CD deviation, and a sum of the required exposure energy and the first/second energy compensation is the exposure energy applied to the exposing layer.

Dependencies are inferred from the claim text.