| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a mask blank in which a halftone mask with high patterning accuracy can be formed by suppressing side etching of a light-shielding layer, and to provide a halftone mask having high patterning accuracy formed from the mask blank. <P>SOLUTION: The mask blank comprises a transparent substrate, a translucent layer, an etching stopper layer and a light-shielding layer, layered in this order. The translucent layer has a first optical density, and the etching stopper layer has a second optical density. The light-shielding layer has a thickness of 20 nm or more and 95.2 nm or less and has a third optical density that gives a sum of the first optical density and the second optical density of 3.0 or more. By controlling the thickness of the light-shielding layer in the above range, an amount of side etching in the light-shielding layer when the translucent layer is etched can be decreased, and thereby, a light-shielding portion of a halftone mask produced from the mask blank can sufficiently block incident light. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
