A photomask for negative-tone development (NTD) includes a main region, and a scribe lane region surrounding the main region and including a first lane and a second lane. The first and the second lane is provided at first opposite sides of each other with respect to the main region. The first lane includes a first sub-lane extending in a first direction and a second sub-lane that extending in the first direction. The first sub-lane includes a first dummy pattern and the second sub-lane includes a second dummy pattern. The first dummy pattern and the second dummy pattern are configured to radiate light exceeding a threshold dose of light to a first portion of a negative-tone photoresist provided under the first lane of the photomask.