Patent ID: 7547502

Claim:
An exposure method comprising the step of illuminating a mask having a contact hole pattern that includes a hybrid pattern using an illumination light that forms an effective source that has plural sources, and projecting an image of the mask onto a plate through a projection optics, the hybrid pattern including a matrix pattern in which plural contact holes are arranged in a matrix shape, and a checker pattern in which plural contact holes are arranged in a checker shape, wherein the matrix pattern has n i pitches, in which Px i is an i-th pitch between contact holes in a array direction, and Py i is an i-th pitch between contact holes in a column direction, the checker pattern has n j pitches, in which Px j is a j-th pitch between contact holes in a array direction, and Py j is a j-th pitch between contact holes in a column direction, NA is a numerical aperture of the projection optics, and λ is a wavelength of the illumination light, wherein the following equations are satisfied: Pxo i /2=(Px i /2) NA/λ, 1≦ i≦n i , Pyo i /2=(Py i /2) NA/λ, 1≦ i≦n i , Pxo j /2=(Px j /2) NA/λ, 1≦ j≦n j , Pyo j /2=(Py j /2) NA/λ, 1≦ j≦n j , α i =tan −1 (Pxo i /Pyo i ), 1≦ i≦n i , α j =2 tan −1 (Pxo j /(2Pyo j )), 1≦ j≦n j , a i =1/(4(Pyo i /2))/sin(α i ), 1≦ i≦n i , a j =1/(4(Pyo j /2))/sin(α j ), 1≦ j≦n j , and wherein a distance between each centroid of the plural sources in the effective source and a center of the pupil in the projection optics is the same as a i , the centroid of the plural sources being located at angles α i , π−α i , π+α i , and 2π−α i where α i is an angle from the array direction viewed from the center of the pupil, a distance between each centroid of the plural sources in the effective source and a center of the pupil in the projection optics being the same as a j , the centroid of the plural sources being located at angles α j , π−α j , π+α j , and 2π−α j where α j is an angle from the column direction viewed from the center of the pupil, and three or four diffracted lights from the contact hole pattern interfering with each other.