PURPOSE: To obtain a photomask material almost free from defects and having superior etching characteristics, high acid and heat resistances by continuously forming an electrically conductive transparent film, a light shielding film and a reflection preventing film on a transparent support in order by sputtering.
CONSTITUTION: An electrically conductive transparent film is formed on a transparent support by sputtering Sn or the like as a target in an Ar-O2 mixed atmosphere under 3×10-3Torr by a DC magnetron method. Evacuation is carried out once, and Cr or the like is sputtered in Ar under 3×10-3Torr to form a light shielding film. A reflection preventing film of chromium oxide or the like is then formed by sputtering Cr or the like as a target in a gaseous mixture of Ar with O2 under 3×10-3Torr. Thus, a photomask material almost free from defects such as pinholes and having favorable etching characteristics, superior acid and heat resistances is obtd. The unevenness of the edges of the resulting pattern is ≤±0.03μm, and the extent of side etching is reduced.
MARUYAMA AKIRA
HIOKA KEIKO
| JPS5451832A | 1979-04-24 |