| abstract |
(57) [Problem] In a conventional process, the yield of manufacturing a halftone mask is small. This is because the ashing rate by O 2 plasma becomes unstable. When the ashing rate is low, the halftone resist cannot be removed, so that a halftone mask cannot be manufactured. A molybdenum silicide film, a chromium film, and an electron beam resist are sequentially formed on a quartz substrate. Next, a first drawing region where a part of the electron beam resist remains by a predetermined thickness even after the development, and a second drawing region where the electron beam resist 4 is completely removed by the development are formed. Next, after development, the chromium film 3 is masked using the electron beam resist 4 from which the second drawing area 4b is completely removed. After the etching, ashing is performed until the resist in the first drawing area has a predetermined film thickness. Next, using the patterned chromium film 3 as a mask, the molybdenum silicide film 2 And at the same time, the electron beam resist 4a in the first drawing area is completely removed. Next, the chromium film 3 is patterned using the electron beam resist 4 not drawn by the electron beam as a mask. |