| 摘要 |
An optical image is formed in a radiation-sensitive layer (5), by a number of sub-illuminations, in each of which an array of light valves (21-25) and a corresponding array (40) of converging elements (43) are used to form a pattern of spots in the resist layer (5) in accordance with a sub-image pattern. Between the sub-illuminations, the resist layer (5) is displaced relative to the arrays (21-25, 40). The lens array (40) may be tilted with respect to the scan area, such that each resist layer area is scanned by a number of spots. In addition, some spot overlap also occurs in a direction perpendicular to the scan direction. This spot redundancy is utilised by selectively reducing the intensity, or switching off, one or more of the redundant spots so as to alter the position of an edge of a device feature, i.e. "fine tune" it. |
