Method for rapid indirect determination of photoresist line widths in optical projection exposure

摘要

The invention relates to a method for rapid indirect determination of photoresist line widths in optical projection exposure, in which test structures consisting of a series of grid structures having different sizes of grid element are received into the original, which contains the structures to be transferred into the photoresist during the exposure operation, the grid constant of these structures being chosen so small that only the zero defraction order is projected during the exposure. After exposure and development, a specific grid- element size is assigned to a specific line-width, at a given exposure dose and in accordance with the different light intensity coupled in, and the line-width measurement is carried out with the aid of this assignment. The method is used in photolithographic processes in the production of integrated circuits using VLSI technology and permits rapid line-width measurements in the 1- mu m range with a tolerance of less than + 0.1 mu m. IMAGE