Apparatus for exposing peripheral portion of substrate

An exposing apparatus for exposing the periphery portion of a substrate on which photoresist is uniformly applied while rotating said substrate by rotating means around a substantially central portion of said substrate, said exposing apparatus comprising:

• irradiating means capable of radiating either one of a first light beam, which is sensed by said photoresist, and a second light beam, which is not sensed by said photoresist, toward the periphery portion of said substrate;
• light receiving means disposed to confront said irradiating means, receiving the radiated light beam and outputting a light receipt signal in accordance with the quantity of received light, said substrate being disposed between said irradiating means and said light receiving means so as to shield a portion of the radiated light beam;
• detection means for detecting the rotational angle of said substrate and outputting an angular signal;
• moving means for relatively moving the radiated light beam and said substrate in a radial direction;
• determining mean for determining the quantity of a relative movement between said second light beam and said substrate, which is necessary to make the radial directional width of a region of said peripheral portion of said substrate which is irradiated with said second light beam to be uniform, in accordance with said light receipt signal when said second light beam is radiated by said irradiating means and said substrate is rotated;
• memorizing means for memorizing said quantity of said relative movement in such a manner that it is made to correspond to said angular signal;
• and
• control means for controlling said moving means in accordance with said quantity of said relative movement and said angular signal memorized by said memorizing means when said first light beam is radiated by said irradiating means and said substrate is rotated so as to relatively move said first light beam and said substrate.