Patent ID: 8703392

Claim:
A method of fabricating a semiconductor device, comprising: providing a substrate having a material layer formed thereon; depositing a photoresist layer on the material layer, the photoresist layer having a vertical dimension; exposing a region of the photoresist layer to radiation, the exposed region having a horizontal dimension, wherein a first ratio of the vertical dimension of the photoresist layer to the horizontal dimension of the exposed region exceeds a predetermined ratio; and applying a developer solution having a ratio of a first chemical and a second chemical based on the first ratio to avoid a footing being formed in the photoresist layer after applying the developer solution, wherein: the first chemical is configured to dissolve the exposed region of the photoresist layer through a chemical reaction; the second chemical is configured to enhance a flow of the first chemical that comes into contact with the photoresist layer; and an optimized second ratio exists between the first chemical and the second chemical.