Euv photomask and manufacturing method of the same

A method of manufacturing a photomask, comprising:

• providing a substrate;
• depositing a multilayer stack comprising Mo/Si layers over the substrate, the multilayer stack comprising a first portion and a second portion circumscribing the first portion;
• and
• performing a treatment on the second portion, wherein a total thickness of the multilayer stack in the second portion is less than that of the first portion after the treatment.

A photomask, comprising:

• a substrate;
• and
• a multilayer stack over the substrate, wherein the multilayer stack is configured to reflect a patterning radiation, comprises alternating molybdenum layers and silicon layers, and includes a first area and a second area laterally surrounding the first area,
• wherein the second area comprises a reflectivity value less than about 0.05% with respect to extreme ultraviolet.