Patent ID: 7029798

Claim:
A method of forming a topographical pattern in a surface of a resist layer, comprising sequential steps of: (a) providing a substrate having a surface; (b) forming a layer of a resist material of a desired thickness on said substrate surface, said resist layer having an exposed upper surface; (c) subjecting selected areas of said exposed upper surface of said resist layer to exposure to an energy beam to form therein a latent image of a desired topographical pattern to be formed in said resist layer; (d) contacting said exposed upper surface of said resist layer with a liquid developing solution comprising a preselected solvent for developing said latent image into said desired topographical pattern, and simultaneously supplying ultrasonic energy to said solution, the combination of supplying said ultrasonic energy to said liquid developing solution comprising said preselected solvent providing improved image contrast between the selected, exposed areas and unexposed areas of said resist layer and increasing an interval for developing said latent image from several seconds to tens of minutes, relative to when said liquid developing solution does not comprise said preselected solvent and said ultrasonic energy is not supplied thereto.