| 摘要 |
PURPOSE:To obtain a photomask having a high accuracy by forming successively a light shielding thin metallic film on a light transmitting glass base plate, and a photomask, forming a thick pattern by a shorter etching than a prescribed time when etching the thin metallic film, measuring this line width, and thereafter, executing an additional etching. CONSTITUTION:A Cr film 2, etc. are formed as a light shielding thin metallic film on the main surface of a light transmitting glass base plate 1. Subsequently, a photoresist 3 is formed on the film 2, and a resist pattern 7 is formed by executing an exposure (shown with an arrow 6) by using an exposing mask 5 having a desired pattern line width, and executing a development. Next, post-baking is executed in a dry N2 gas, and thereafter, the film 2 is etched. As for the etching time, and thereafter, a Cr pattern 8' width X3 is measured. How larger it is than a desired pattern X0 is known, and an additional etching time is determined from an etching speed derived in advance, by which an exact Cr pattern width X0 is obtained. Subsequently, a photomask 9 having a high accuracy is obtained by removing the resist 7. |
