Device for exposure of a peripheral area

A device for exposing a peripheral area of a wafer having an outside peripheral area with a photoresist applied thereon and provided with a notch, whereby the photoresist is exposed by rotation of the wafer and by simultaneous irradiation of the photoresist in the peripheral area of the wafer with exposure light to form an irradiation area, the device comprising:

• means for edge determination including a projection part for projecting sensor light and a light receiving part for receiving the sensor light, said projection part projecting the sensor light onto the peripheral area of the wafer and the light receiving part receiving the sensor light emitted onto the edge area of the wafer;
• a moving device adapted to move the edge determination means in a direction toward a center of the wafer;
• an irradiation area moving device adapted to move the irradiation area;
• a notch determination means for determining the notch, said notch determination means being located integrally with the edge determination means upwards of the edge determination means;
• and
• a controller adapted to control the moving device to cause the amount of light received by this light receiving part to become constant, the controller further adapted to control the irradiation area moving device to move the irradiation area in the same direction as the direction of motion of the edge determination means and by a same amount as an amount of movement of the edge determination means, wherein the controller stops operation of the irradiation area moving device after a time period following reception by the controller of a notch start signal from the notch determination means, and restarts operation of the irradiation area moving device after a given time has passed.