Photomask and exposure method

A photomask comprising:

• a substrate;
• a reflective layer that is arranged on a first surface of the substrate, the reflective layer configured to reflect light;
• a light-shielding pattern that is arranged on a second surface of the reflective layer opposite to the substrate and includes a light-absorbing layer configured to absorb the light;
• and
• a pellicle that is spaced apart from the light-shielding pattern to face the first surface, wherein
• the pellicle includes:
• an area that has a first end portion at a position corresponding to one end portion of the substrate and has a second end portion at a position corresponding to a position located inward from the one end portion of the substrate by a predetermined distance;
• and
• a first layer that thickens from the second end portion toward the first end portion.

An exposure method comprising:

• exposing a first area extending from one end portion of a shot area provided on a wafer to a position of the shot area located inward by a first distance from the one end portion, by using a first photomask;
• and
• exposing a second area extending from the other end portion of the shot area to a position of the shot area located inward by a second distance from the other end portion, by using a second photomask, and exposing the shot area while a third area located at a center portion of the shot area is subjected to double exposure, wherein
• the first and second photomasks each including a stitching area that corresponds to the third area, has a first end portion at one end portion of each of the first and second photomasks, and has a second end portion at a position located inward from the one end portion by a predetermined distance, the first and second photomasks each include:
• a substrate;
• a reflective layer that is arranged on a first surface of the substrate, the reflective layer configured to reflect light;
• and
• a light-shielding pattern that is arranged on a second surface of the reflective layer opposite to the substrate and includes a light-absorbing layer configured to absorb the light, wherein
• in the stitching area, a reflection intensity of the light is lower on a side of the first end portion than on a side of the second end portion.