Exposure method
AssigneeCanon Kabushiki Kaisha
InventorMiyoko Kawashima
Life of this patent
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Abstract
An exposure method includes 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 poles, and projecting an image of the mask onto a plate through a projection optics. The hybrid pattern includes 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. Three or four diffracted lights from the contact hole pattern interfere with each other.
Claims11
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 ni pitches, in which Pxi is an i-th pitch between contact holes in a array direction, and Pyi is an i-th pitch between contact holes in a column direction, the checker pattern has nj pitches, in which Pxj is a j-th pitch between contact holes in a array direction, and Pyj 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:
- Pxoi/2=(Pxi/2)NA/λ, 1≦i≦ni,
- Pyoi/2=(Pyi/2)NA/λ, 1≦i≦ni,
- Pxoj/2=(Pxj/2)NA/λ, 1≦j≦nj,
- Pyoj/2=(Pyj/2)NA/λ, 1≦j≦nj,
- αi=tan−1(Pxoi/Pyoi), 1≦i≦ni,
- αj=2 tan−1(Pxoj/(2Pyoj)), 1≦j≦nj,
- ai=1/(4(Pyoi/2))/sin(αi), 1≦i≦ni,
- aj=1/(4(Pyoj/2))/sin(αj), 1≦j≦nj, 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 ai, the centroid of the plural sources being located at angles αi, π−αi, π+αi, and 2π−αi where αi 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 aj, the centroid of the plural sources being located at angles αj, π−αj, π+αj, and 2π−αj where αj 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.
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 four poles, 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 a distance between each centroid of the four poles in the effective source and a center of the pupil in the projection optics is the same as a, the centroids of the four poles being located at angles α, π−α, π+α, and 2π−α where α is an angle from a array direction viewed from the center of the pupil, the matrix pattern having a pitch Px1 between contact holes in a array direction, and a pitch Py1 between the contact holes in a column direction, the checker pattern having a pitch Px2 between contact holes in a array direction, and a pitch Py2 between the contact holes in a column direction, NA being a numerical aperture of the projection optics , and λ being a wavelength of the illumination light, and
- wherein the following equations are satisfied:
- Pxo1/2=(Px1/2)NA/λ,
- Pyo1/2=(Py1/2)NA/λ,
- Pxo2/2=(Px2/2)NA/λ,
- Pyo2/2=(Py2/2)NA/λ,
- α1=tan−1(Pxo1/Pyo1),
- α2=2 tan−1(Pxo2/(2Pyo2)),
- a1=1/(4(Pyo1/2))/sin(α1),
- a2=1/(4(Pyo2/2))/sin(α2),
- α contains α1 and α2, a contains a1 and a2, and three or four diffracted lights from the contact hole pattern interfering with each other.
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 eight poles, 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 a distance between each centroid of the eight poles in the effective source and a center of the pupil in the projection optics is the same as a1, the centroids of the plural poles being located at angles α1, π−α1, π+α1, and 2π−α1 where α1 is an angle from a array direction viewed from the center of the pupil, and is the same as a2, the centroids of the eight poles being located at angles α2, π−α2, π+α2, and 2π−α2 where α2 is an angle from a column direction viewed from the center of the pupil, the matrix pattern having a pitch Px1 between contact holes in a array direction, and a pitch Py1 between the contact holes in a column direction, the checker pattern having a pitch Px2 between contact holes in a array direction, and a pitch Py2 is between the contact holes in a column direction, NA being a numerical aperture of the projection optics , and λ being a wavelength of the illumination light,
- wherein the following equations are satisfied:
- Pxo1/2=(Px1/2)NA/λ,
- Pyo1/2=(Py1/2)NA/λ,
- Pxo2/2=(Px2/2)NA/λ,
- Pyo2/2=(Py2/2)NA/λ,
- α1=tan−1(Pxo1/Pyo1),
- α2=2 tan−1(Pxo2/(2Pyo2)),
- a1=1/(4(Pyo1/2))/sin(α1),
- a2=1/(4(Pyo2/2))/sin(α2), and
- three or four diffracted lights from the contact hole pattern interfering with each other.
Dependencies are inferred from the claim text.