Photomask and method of manufacturing or repairing photomask

A photomask, comprising:

• a substrate;
• and
• a first mask pattern structure, including:
• a first light blocking structure over the substrate in a vertical direction, and a first insulation structure over the substrate in the vertical direction, the first insulation structure including a first lower insulation portion and a first upper insulation portion, the first lower insulation portion being between the first light blocking structure and the substrate, and the first upper insulation portion covering at least an upper surface of the first light blocking structure,
• wherein
• an overall light transmittance of the first mask pattern structure along the vertical direction ranges from 3% to 10%.

A method of repairing a photomask, the method comprising:

• removing a target mask pattern structure from a substrate, the target mask pattern structure corresponding to a target mask pattern;
• and
• forming a replacement mask pattern structure over the substrate, the replacement mask pattern structure corresponding to the target mask pattern, and the forming the replacement mask pattern structure comprises:
• depositing a lower insulation portion of an insulation structure over the substrate in a vertical direction;
• forming a light blocking structure over the lower insulation portion in the vertical direction, the lower insulation portion being between the light blocking structure and the substrate;
• and
• depositing an upper insulation portion of the insulation structure covering at least an upper surface of the light blocking structure,
• wherein
• one or more characteristics of the light blocking structure, the lower insulation portion, and the upper insulation portion are configured such that an overall light transmittance of the replacement mask pattern structure along the vertical direction ranges from 3% to 10%.