| 摘要 |
<p>PURPOSE:To obtain an upper shifter type phase shift photo mask which is capable of dealing with the trend toward the higher fineness and higher integration of the photo mask by polishing away the ruggedness on the surface of a shifter layer generated by the difference in level arising from the patterns of a light shielding layer, thereby flattening the surface. CONSTITUTION:At least light shielding layer patterns 103 and an etching stopper layer 102 for the light shielding layer patterns 103 and the shifter layer are formed on a transparent substrate 101. The shifter layer 104 is formed thereon over the entire surface and thereafter, the shifter layer patterns are formed. This process includes a stage for polishing away the ruggedness on the surface of the shifter layer 104 generated by the level in difference occurring in the light shielding layer patterns 103, thereby flattening the surface. The shifter layer 104 is formed flat with no more influence of the difference in level by the underlying light shielding layer patterns 103 and, therefore, the shifter layer thickness of the shifter patterns is formed to be uniform within the same light transparent parts (within the apertures). As a result, the disturbance in phase is not generated within the same apertures at the time of projectionexposure to a wafer.</p> |
