| 摘要 |
PURPOSE:To uniform the width dimension of a resist pattern over the whole surface of a wafer, by a method wherein a photoresist film substantially uniformly applied is exposed to light in such a step-and-repeat manner that the exposure time is gradually varied from the peripheral areas toward the center. CONSTITUTION:A positive photoresist is rotationally applied to an Si wafer having a diameter of about 100mm. and provided with an SiO2 film. As a result, a resist film is formed having a film thickness varying from the center toward the peripheral edges. After prebaking, an exposure is effected while the exposure time is gradually decreased from the peripheral edge areas toward the center with a step pitch of 10mm.X10mm., for example, so that the exposure time is 0.2sec in the center and is 0.4sec at the peripheral edge areas. The longer the exposure time, the smaller in width of the positive resist pattern. Therefore, by carrying out exposure and development according to this constitution, the resist pattern width can be unifored over the whole surface. In the case of a negative photoresist, it will suffice to reverse the exposure time. |
