Patent ID: 6537837
Filing Date: 2003-03-25
Classification: G03F

Abstract:
A method of forming a pattern on a photoresist layer covering a wafer, comprising:performing a first exposure on the photoresist layer using a first alternating phase shift mask, the first alternating phase shift mask including a first non-phase shift region through which light is transmittable and light phase is not changed, a first phase shift region through which light is transmittable and light phase is changed, and first a non-transparent region through which light cannot be transmitted, the first non-transparent region being located between the first non-phase shift region and the first phase shift region on a first mask substrate; performing a second exposure on the photoresist layer using a second alternating phase shift mask, the second alternating phase shift mask including a second non-phase shift region through which light is transmittable and light phase is not changed, a second phase shift region through which light is transmittable and light phase is changed, and a second non-transparent region through which light cannot be transmitted, the second non-transparent region being located between the second non-phase shift region and the second phase shift region, on a second mask substrate, wherein during the second exposure, the second phase shift region and the second non-phase shift region of the second alternating phase shift mask respectively correspond to the first non-phase shift region and the first phase shift region of the first alternating phase shift mask.