Phase-width balanced alternating phase shift mask design

摘要

A method is provided for designing an altPSM mask including a substrate. The method includes the following steps. Provide a circuit layout. Identify critical elements of the circuit layout. Provide a cutoff layout dimension. Identify critical segments of the circuit layout which are critical elements with a sub-cutoff dimension less than the cutoff dimension. Create basic phase shapes associated with the critical segments. Remove layout violations from the phase shapes. Determine whether the widths of phase shapes associated with a critical segment have unequal narrower and wider widths. If YES, then widen each narrower phase shape to match the width of wider phase shape associated with the critical segment and repeat the steps starting with removal of layout violations until the test answer is NO. When the test answer is NO, provide a layout pattern to an output.