Position measurement apparatus and method and pattern forming apparatus and writing method
First Claim
1. A position measurement apparatus comprising:
- a movable stage structure;
a measurement unit using a laser to measure a moved position of the stage and to output a corresponding measured value;
a first filter configured to attenuate a first component of a certain frequency region of the measured value outputted by said measurement unit;
a second filter connected in parallel with said first filter configured to attenuate a second component other than the certain frequency region of the measured value outputted by said measurement unit;
a third filter connected in series to said second filter with the series connection of said second and third filters connected in parallel with the first filter, configured to attenuate the first component of said certain frequency region of the measured value outputted by said measurement unit; and
a processing unit configured to combine an output of said first filter and an output of the series connection of the second and third filters and to thereby output a first combined value,wherein transfer function of the first filter is given by 1/(1+τ
1·
S) using a time constant τ
1 and a Laplace operator S, transfer function of the second filter is given by τ
2·
S/(1+τ
·
S) using a time constant τ
2 and the Laplace operator S, and transfer function of the third filter is given by 1/(1+τ
3·
S) using a time constant τ
3 and the Laplace operator S.
1 Assignment
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Accused Products
Abstract
A position measurement apparatus includes a movable stage structure, a measurement unit using a laser to measure a moved position of the stage and to output a corresponding measured value, a first filter configured to attenuate a first component of a certain frequency region of the measured value outputted by the measurement unit, a second filter connected in parallel with the first filter configured to attenuate a second component other than the certain frequency region of the measured value outputted by the measurement unit, a third filter connected in series to the second filter with the series connection of the second and third filters connected in parallel with the first filter, configured to attenuate the first component of the certain frequency region of the measured value outputted by the measurement unit, and a processing unit configured to combine an output of the first filter and an output of the series connection of the second and third filters and to thereby output a first combined value.
411 Citations
19 Claims
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1. A position measurement apparatus comprising:
-
a movable stage structure; a measurement unit using a laser to measure a moved position of the stage and to output a corresponding measured value; a first filter configured to attenuate a first component of a certain frequency region of the measured value outputted by said measurement unit; a second filter connected in parallel with said first filter configured to attenuate a second component other than the certain frequency region of the measured value outputted by said measurement unit; a third filter connected in series to said second filter with the series connection of said second and third filters connected in parallel with the first filter, configured to attenuate the first component of said certain frequency region of the measured value outputted by said measurement unit; and a processing unit configured to combine an output of said first filter and an output of the series connection of the second and third filters and to thereby output a first combined value, wherein transfer function of the first filter is given by 1/(1+τ
1·
S) using a time constant τ
1 and a Laplace operator S, transfer function of the second filter is given by τ
2·
S/(1+τ
·
S) using a time constant τ
2 and the Laplace operator S, and transfer function of the third filter is given by 1/(1+τ
3·
S) using a time constant τ
3 and the Laplace operator S. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A pattern forming apparatus comprising:
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a movable stage supporting thereon a workpiece; a measurement unit configured to measure a moved position of said stage by use of a laser and to output a corresponding measured value; a low-pass filter for causing the measured value outputted by said measurement unit to pass therethrough while being set at a prespecified cut-off frequency; a first matched pair comprising a low-pass and a high-pass filter, each having a cut-off frequency being set equal to the prespecified cut-off frequency, for causing the measured value outputted by said measurement unit to pass therethrough; and a pattern writing unit responsive to receipt of a first combined value of an output of said low-pass filter and an output of said first matched pair comprising the low-pass and the high-pass filter, for writing a pattern on the workpiece at a desired position thereof, wherein transfer function of the low-pass filter is given by 1/(1+τ
1·
S) using a time constant τ
1 and a Laplace operator S, transfer function of the high-pass filter of the first matched pair is given by τ
2·
S/(1+τ
2·
S) using a time constant τ
2 and the Laplace operator S, and transfer function of the low-pass filter of the first matched pair is given by 1/(1+τ
3·
S) using a time constant τ
3 and the Laplace operator S. - View Dependent Claims (10, 11, 12, 13)
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14. A position measurement method comprising:
-
measuring a moved position of a stage by using a laser; removing a nonlinear error component from a measured value by use of a low-pass filter being set to a predefined cutoff frequency; and correcting, by using a first matched pair comprising a low-pass and a high-pass filter each having a cutoff frequency being set equal to said predefined cutoff frequency, a phase delay occurred in said measured value due to the use of said low-pass filter upon removal of the nonlinear error component, wherein transfer function of the low-pass filter is given by 1/(1+τ
1·
S) using a time constant τ
1 and a Laplace operator S, transfer function of the high-pass filter of the first matched pair is given by τ
2·
S/(1+τ
2·
S) using a time constant τ
2 and the Laplace operator S, and transfer function of the low-pass filter of the first matched pair is given by 1/(1+τ
3·
S) using a time constant τ
3 and the Laplace operator S. - View Dependent Claims (15)
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16. A position measurement method comprising:
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measuring a moved position of a stage by using a laser; removing a nonlinear error component from a measured value by use of a low-pass filter being set to a predefined cutoff frequency; and correcting occurrence of a velocity-proportional position deviation against said measured value by using a first matched pair comprising a low-pass and a high-pass filter each having a cutoff frequency identical to said predefined cutoff frequency, wherein transfer function of the low-pass filter is given by 1/(1+τ
1·
S) using a time constant τ
1 and a Laplace operator S, transfer function of the high-pass filter of the first matched pair is given by τ
2·
S/(1+τ
2·
S) using a time constant Ε
2 and the Laplace operator S, and transfer function of the low-pass filter of the first matched pair is given by 1/(1+τ
3·
S) using a time constant t3 and the Laplace operator S. - View Dependent Claims (17)
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18. A writing method comprising:
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measuring a moved position of a stage by using a laser; removing a nonlinear error component from a measured value by use of a low-pass filter being set to a predetermined cutoff frequency; and correcting, by using a first matched pair comprising a low-pass and a high-pass filter each having a cutoff frequency identical to said predetermined cutoff frequency, occurrence of a velocity-proportional position variation with respect to said measured value; and writing a pattern on said workpiece at a desired position in response to receipt of a first combined value of an output of said low-pass filter and an output of said first matched pair comprising the low-pass and the high-pass filter, wherein transfer function of the low-pass filter is given by 1/(1+τ
1·
S) using a time constant τ
1 and a Laplace operator S, transfer function of the high-pass filter of the first matched pair is given by τ
2·
S/(1+τ
2·
S) using a time constant τ
2 and the Laplace operator S, and transfer function of the low-pass filter of the first matched pair is given by 1/(1+τ
3·
S) using a time constant τ
3 and the Laplace operator S. - View Dependent Claims (19)
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Specification