EMBEDDED ATTENUATED PHASE SHIFT MASK AND METHOD OF MAKING EMBEDDED ATTENUATED PHASE SHIFT MASK

摘要

An embedded attenuated phase shift mask ("EAPSM") includes an etch stop layer that can be plasma etched in a process that is highly selective to the underlying quartz substrate. Selectivity to the underlying quartz maintains a desired 180 degree phase shift uniformly across the active mask area. Conventional plasma etching techniques can be utilized without damage to the underlying quartz substrate. Alternatively, the etch stop layer comprises a transparent material that can remain intact ion the mask structure.