| 摘要 |
PURPOSE:To decrease extremely black color defects and to improve quality of a mask by constituting a mask blank material of the 1st light shieldable film to be dry etched on a substrate and the 2nd light shieldable film which is resistant to dry etching and is to be wet etched. CONSTITUTION:The photomask blank 4 is constituted of the 1st light shieldable film 2 which is to be dry etched and consists of a Ta film, etc. on the light transmittable substrate 1 consisting of quartz glass, etc. and the 2nd light shieldable film 3 which is resistant to the dry etching, is to be wet etched and consists of a Cr film, etc. A photoresist 5 is coated on such film and is exposed and developed to form a resist pattern 8 and thereafter the dry etching is executed to form the 2nd light shieldable film pattern 9. The film 2 is dry etched with the pattern 9 as a mask. The thorough cleaning and drying are executed prior to the etching of the film 2 and therefore the foreign matter is removed and the black color defects are eliminated. The quality of the mask is thus improved. |
