Norihisa Koga

Advanced edge resist remover for photomask

In photomask manufacturing, the corner and the edge of the photomask are stained by photo-resist after coating. Since such resist remains cause the particles when substrates are transferred inside the photomask manufacturing equipment, it is important to remove the stained areas. The scanning type photomask edge resist remover developed this time enables a rapid and accurate resist removal compared with similar type tool. Besides, the edge remover reduces the process time of edge resist removal to set slightly narrowing the removal width. The removal speed varies according to removal conditions; it decreases when the resist film density is high such as after the pre-bake. When determining removal conditions, defect and linearity of resist removal line should be well considered as well as the removal speed. It is important to define a balance among the thinner dispense rate, N2 flow and exhaust pressure to prevent defects and optimize the arm velocity to obtain good linearity of resist removal line. With this new edge resist remover, it is also possible to make a complex removal line that is difficult by conventional technology.