| 摘要 |
PURPOSE:To dry-etch an X-ray absorbing metal layer on an X-ray film while maintaining a high selection ratio to the film in a manufacture of a mask for X-ray lithography. CONSTITUTION:A W film 3 (X-ray absorbing metal layer) formed on a SiN film 2 (X-ray transmitting film) is etched using a S2F4 gas. The W film 3 is removed in the form of WFx, and an S-deposited layer 6 is formed on the side wall surface of a pattern by S (sulphur) dissociated from the S2F2. When the underlying SiN film 2 is exposed, the S atom in a plasma couples with the dangling bond of the N atom having appeared on the exposed surface, whereby a sulphur nitride deposit layer 7 mainly composed of polythiazyl (SN)x is formed. By the surface protection effect of the sulphur nitride deposit layer 7, the high selectivity for the ground is achieved. |
