| 摘要 |
In a method of manufacturing a phase-shift photomask comprising the steps of preparing a substrate transparent to an exposure light having a wavelength lambd and having a refraction factor n, forming, on the substrate, a pattern including a light-blocking portion blocking the light entering and a light transmission portion transmitting light, and etching the substrate on the transmission portion including a plurality of transmission sections so as to provide adjacent transmission sections, one having a recessed depth d1 and the other one having a recessed depth d2 so as to satisfy an equation of (d1-d2)=lambd/2(n-1), the etching step comprises a first etching process of a selective dry-etching to the light transmission section of the substrate having the depth d1 so as to provide a predetermined depth D1 after the formation of the light-blocking portion, a second etching process of a wet-etching process to the transmission section having the depth d1 so as to provide a depth of lambd/2(n-1), and a third etching process of a wet-etching to all the light transmission section having the depth d1 and the depth d2 so as to satisfy an equation of (d1-d2)=lambd/2(n-1).
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