| 摘要 |
<p>1287031 Photographic reversal process; photomasks INTERNATIONAL BUSINESS MACHINES CORP 8 Jan 1970 [10 Jan 1969] 1044/70 Headings G2C and G2M Photo-masks are prepared on a substrate coated with a photographic gelatino silver halide emulsion by (1) exposing, (2) developing the exposed areas (3) removing the visible image formed (bleaching), and (4) heating to above 250‹C. to remove the coating in the exposed areas. The non-exposed coating may be rendered visible between steps (3) and (4) by exposure and development or by treatment with a reducing agent. The mask formed may be covered with a layer of metal (e.g. G), the metal overlying the remaining emulsion removed (e.g. with aqueous hypochlorite), and the remaining emulsion removed (e.g. with HNO 3 ) leaving a metal mask.</p> |
