Process of transfer of mask pattern onto substrate and apparatus for alignment therebetween
First Claim
1. An apparatus for successively aligning a first pattern formed on a photomask with a plurality of identical second patterns formed, according to a prescribed arrangement, on a substrate, comprising:
- stage means adapted for supporting said substrate and movable two-dimensionally along the face of said substrate;
means for detecting relative rotational error between said first pattern and at least one of said plurality of second patterns;
means for causing relative rotation between said photomask and said substrate in order to compensate the relative rotational error detected by said detecting means and to correct the rotational aberrations of each of said second patterns; and
means for controlling the movement of said stage means according to said prescribed arrangement so as to align said first pattern with each of said second patterns successively.
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Accused Products
Abstract
In an exposure apparatus for manufacturing semiconductor devices, a pattern on a photomask is aligned with a plurality of patterns formed on a wafer in a manner that detects and corrects misalignment, including, inter alia, rotational errors, not only between a photomask and a wafer, but also between a photomask and individual chips formed on the wafer, so that pattern matching is attained with very high accuracy. Apparatus for achieving this result employs different arrangements of alignment marks together with optical systems and positional adjustment devices.
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Citations
17 Claims
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1. An apparatus for successively aligning a first pattern formed on a photomask with a plurality of identical second patterns formed, according to a prescribed arrangement, on a substrate, comprising:
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stage means adapted for supporting said substrate and movable two-dimensionally along the face of said substrate; means for detecting relative rotational error between said first pattern and at least one of said plurality of second patterns; means for causing relative rotation between said photomask and said substrate in order to compensate the relative rotational error detected by said detecting means and to correct the rotational aberrations of each of said second patterns; and means for controlling the movement of said stage means according to said prescribed arrangement so as to align said first pattern with each of said second patterns successively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for successively aligning a first pattern formed on a photomask with a plurality of identical second patterns formed on a substrate at a determined pitch, comprising:
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means for supporting said photomask, said photomask having means for indicating a reference direction of said first pattern; stage means for supporting said substrate and capable of two-dimensional movement with said substrate, said substrate having means for indicating respective directions of said second patterns corresponding to said reference direction of said first pattern; means for detecting relative rotational error of the direction of at least one of said second patterns relative to said reference direction of said first pattern; means for rotating said substrate relative to said photomask in order to compensate the relative rotational error detected by said detecting means and to correct the rotational aberrations of each of said second patterns; means for determining a coordinate system on said substrate provided with a corrdinate axis corresponding to said reference direction of said first pattern and determining positions of said second patterns along said coordinate system on said substrate compensated by said rotating means; and means for moving said stage means in response to said determining means. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A method for successively aligning a first pattern formed on a photomask with plural second patterns formed on a substrate along a reference direction, comprising the steps of:
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(a) positioning said photomask on a first stage and said substrate on a second stage; (b) detectinng rotational error θ
C which each of said second patterns has relative to said reference direction;(c) rotating said substrate relative to said photomask by an angle corresponding to said rotational error θ
C and to correct the rotational aberrations of each of said second patterns; and(d) moving said second stage along said reference direction so as to align said first pattern with each of said second patterns successively.
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17. In an apparatus for printing a pattern of a photomask onto a substrate, the apparatus having a fiducial mark, an illumination optical system having a position controllable reference mark and a holder for holding said photomask, a method for carrying out an alignment of said photomask with said apparatus comprising steps of:
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(a) aligning the reference mark of said illumination optical system with said fiducial mark; (b) displacing said holder to align said photomask with the aligned reference mark; (c) fixing the displaced holder to said apparatus; (d) detecting an amount of rotational error of the photomask on the fixed holder with respect to the apparatus; (e) adjusting the position of said reference mark in correspondence with said amount of rotational error to correct said rotational error; (f) re-displacing said holder to align said photomask with the adjusted reference mark; and (g) fixing the re-displaced holder to said apparatus.
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Specification