| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing a five-level gradation photomask, by which five-level gradation can be obtained through three times of etching. <P>SOLUTION: The method for obtaining five-level gradation through three times of etching includes steps of: preparing a photomask blank having a first translucent film having etching selectivity and a light-shielding film in this order on a transparent substrate; forming a first resist pattern on the light-shielding film; etching the light-shielding film by using the first resist pattern as a mask to carry out first patterning; removing the first resist pattern and forming a second resist pattern; etching the first translucent film by using the second resist pattern as a mask to carry out second patterning; removing the second resist pattern and forming a second translucent film having etching selectivity with respect to the first translucent film, over the whole substrate surface; forming a third resist pattern on the second translucent film; and etching the second translucent film by using the third resist pattern as a mask for carrying out third patterning. <P>COPYRIGHT: (C)2011,JPO&INPIT |
