| 摘要 |
PURPOSE:To reduce the number of processes required to produce a photomask for phase shift with a sub-shifter and to enhance the yield of product, of such photomasks. CONSTITUTION:A two-layered film consisting of a silicon nitride film 4a and a silicon oxide film 4b is formed on a glass substrate 2 with a formed light shielding pattern 3a-3c and phase shifters 4 are formed by anisotropic etching of the two-layered film. Only the silicon nitride film 4a exposed to the side walls of the phase shifters 4 is then removed by selective side etching. Sub- shifter regions 5 made of only the silicon oxide film 4a are self-matchably formed at the peripheries of the phase shifters 4 and the objective photomask 1 for phase shift is produced. |
