IPC Definitions - January 01, 2012
G03F 1/34 - Definition
This group covers:
Subject matter of subgroup G03F 1/26 in which the phase shift mask (PSM) has at least two clear regions directly adjacent to each other that produce different phases (usually 180 degrees apart) to create a phase edge between these diverse clear regions in corresponding portions of exiting illumination, where the phase edge represents a pattern to be reproduced (e.g., chromeless PSM, etc.); and in which the process of preparing is directed to preparation of such a phase edge PSM.
Note. In this subgroup, such a phase edge PSM can be without any opaque region (as a chromeless PSM). Alternatively, the phase edge PSM is permitted to include an opaque region or an absorber region, such as at the peripheral border of this phase edge PSM to avoid unwanted artifacts that might otherwise be produced in a common photoresist layer by step-and-repeat exposures from this phase edge PSM. However, this phase edge PSM must still have at least one unobstructed phase edge between two directly adjacent clear regions that produce exiting illumination having different phases (e.g., at 0° and 180°, etc.), where the phase edge represents a pattern to be reproduced, as described above.