Method of forming photoresist pattern, and photoresist structure

A method of forming a photoresist pattern, comprising:

• forming a photoresist structure on a target layer, wherein the photoresist structure comprises a photoresist layer provided on the target layer, and an optical wave transmission layer provided on the photoresist layer;
• and
• performing exposure processing on the photoresist structure in a first medium, and forming an exposure image in the photoresist layer, wherein the optical wave transmission layer is configured to improve lithographic resolution of the photoresist layer;
• wherein the forming a photoresist structure on a target layer comprises:
• coating the target layer with a photoresist solution, wherein the photoresist solution comprises a photoresist composite and a light-transmitting ionic polymer;
• performing soft baking on the target layer coated with the photoresist solution, and evaporating a solvent in the photoresist solution;
• diffusing the photoresist composite to the target layer to form the photoresist layer on a top surface of the target laver;
• and
• diffusing the ionic polymer towards a direction away from the target laver, wherein the ionic polymer forms the optical wave transmission layer on a top surface of the photoresist layer:
• wherein the performing exposure processing on the photoresist structure in a first medium, and forming an exposure image in the photoresist layer comprises:
• transmitting first incident beam to the photoresist structure, wherein the first incident beam has a first wavelength, the first incident beam passes through the first medium to enter the optical wave transmission layer, and the first incident beam is refracted by the optical wave transmission layer and becomes a second incident beam having a second wavelength that is less than the first wavelength, wherein
• the second incident beam enters the photoresist laver, and the second incident beam forms the exposure image in the photoresist layer;
• wherein a thickness of the optical wave transmission layer is greater than 1/10 of the first wavelength, and the thickness of the optical wave transmission layer is less than ⅕ of a thickness of the photoresist laver.