METHODS AND DEVICES FOR DRIVING MICROMIRRORS
First Claim
1. A method, comprising:
- a) providing a micromirror array in an illumination system of a microlithographic projection exposure apparatus, the micromirror array comprising a micromirror which is tiltable through a respective tilt angle about two tilt axes, the micromirror being assigned three actuators, each of the three actuators being capable of being driven by control signals to tilt the micromirror about the two tilt axes;
b) specifying two control variables, each of the two control variables being assigned to one tilt axis, and both of the two control variables being assigned to unperturbed tilt angles;
c) for any desired combinations of the two control variables, as a function of the two control variables, selecting one of the three actuators whose control signal is set to a constant value;
d) determining the control signals so that, when the control signals are applied to the other two actuators, the micromirror adopts the unperturbed tilt angles as a function of the two control variables; and
e) applying the control signals to the actuators.
1 Assignment
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Accused Products
Abstract
A micromirror of a micromirror array in an illumination system of a microlithographic projection exposure apparatus can be tilted through a respective tilt angle about two tilt axes. The micromirror is assigned three actuators which can respectively be driven by control signals in order to tilt the micromirror about the two tilt axes. Two control variables are specified, each of which is assigned to one tilt axis and which are both assigned to unperturbed tilt angles. For any desired combinations of the two control variables, as a function of the two control variables, one of the three actuators is selected and its control signal is set to a constant value, in particular zero. The control signals are determined so that, when the control signals are applied to the other two actuators, the micromirror adopts the unperturbed tilt angles as a function of the two control variables.
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Citations
31 Claims
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1. A method, comprising:
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a) providing a micromirror array in an illumination system of a microlithographic projection exposure apparatus, the micromirror array comprising a micromirror which is tiltable through a respective tilt angle about two tilt axes, the micromirror being assigned three actuators, each of the three actuators being capable of being driven by control signals to tilt the micromirror about the two tilt axes; b) specifying two control variables, each of the two control variables being assigned to one tilt axis, and both of the two control variables being assigned to unperturbed tilt angles; c) for any desired combinations of the two control variables, as a function of the two control variables, selecting one of the three actuators whose control signal is set to a constant value; d) determining the control signals so that, when the control signals are applied to the other two actuators, the micromirror adopts the unperturbed tilt angles as a function of the two control variables; and e) applying the control signals to the actuators. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 20, 21)
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18. A method, comprising:
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a) providing a micromirror array which is arranged in an illumination system of a microlithographic projection exposure apparatus, the micromirror array comprising a micromirror, the micromirror being tiltable through a respective tilt angle about two tilt axes, and the micromirror being assigned three actuators which can be driven by control signals to tilt the micromirror about the two tilt axes; b) compiling an assignment table between the tilt angles and the control signals of the three actuators by activating and measuring a plurality of tilt angles of the micromirror and storing the control signals applied to the three actuators for this; c) specifying two control variables, each of the two control variables being assigned to one tilt axis, and both of the control variables being assigned linearly to the unperturbed tilt angles; d) determining control signals which cause the micromirror to tilt through the unperturbed tilt angles, by linearly assigning the two control variables to the tilt angles of the assignment table according to the assignment in c) and reading out the control signals assigned to these tilt angles from the assignment table; and e) applying the control signals to the actuators.
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19. A method, comprising:
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a) providing a micromirror array which is arranged in an illumination system of a microlithographic projection exposure apparatus, the micromirror array comprising a micromirror, the micromirror being tiltable through a respective tilt angle about two tilt axes, and the micromirror being assigned three actuators which can respectively be driven by control signals in order to tilt the micromirror about the two tilt axes; b) determining at least 3 assignments between the tilt angles and the control signals of the three actuators by activating and measuring various tilt angles of the micromirror and the control signals applied to the three actuators for this; c) estimating a parameter vector from the assignments obtained in b); d) specifying two control variables, each of which is assigned to one tilt axis; e) determining the control signals for given control variables via a calculation rule which uses the estimated parameter vector; and f) applying the control signals to the actuators.
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22. A drive electronics configured to drive a micromirror of a micromirror array, the micromirror array being in an illumination system of a microlithographic projection exposure apparatus, the micromirror having two tilt axes, three actuators being assigned to the micromirror to tilt the micromirror about the two tilt axes, the drive electronics comprising:
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a) a converter comprising an input for control variables which are assigned to unperturbed tilt angles about the two tilt axes; b) two signal amplifiers controllable via the converter; and c) a switching unit configured to apply control signals to the three actuators, wherein; as a function of the control variables applied to the input of the converter, the control signal of one of the three actuators can be set to a constant value via the converter and the switching unit; and the other two control signals can be applied to the actuators via the converter, the switching unit and the two signal amplifiers so that the micromirror adopts the unperturbed tilt angles, assigned to the control variables, about the two tilt axes. - View Dependent Claims (23, 24, 25, 28)
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26. A drive electronics configured to drive a micromirror of a micromirror array, the micromirror array being in an illumination system of a microlithographic projection exposure apparatus, the micromirror having two tilt axes and the micromirror being assigned three actuators, which can respectively be driven by control signals to tilt the micromirror about the two tilt axes, the drive electronics comprising:
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a) a converter comprising an input for control variables which are assigned to unperturbed tilt angles about the two tilt axes; and b) signal amplifiers which can be controlled via the converter and are connected directly or indirectly to the actuators so that the control signals can be applied to the actuators, wherein the converter comprises a memory for an assignment table from which the control signals of the three actuators can be determined as a function of the control variables applied to the input of the converter.
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27. A drive electronics configured to drive a micromirror of a micromirror array, the micromirror array being in an illumination system of a microlithographic projection exposure apparatus, the micromirror having two tilt axes and the micromirror being assigned three actuators which can respectively be driven by control signals to tilt the micromirror about the two tilt axes, the drive electronics comprising:
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a) a converter comprising an input for control variables which are assigned to unperturbed tilt angles about the two tilt axes; and b) signal amplifiers which can be controlled by means of the converter and are connected directly or indirectly to the actuators so that the control signals can be applied to the actuators; wherein the converter comprises a calculation unit by which, via a calculation rule that uses a parameter vector which can be estimated in a parameterisation phase, the control signals of the three actuators can be calculated as a function of the control variables applied to the input of the converter.
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29. A method to switch an illumination setting in an illumination system of a microlithographic projection exposure apparatus, the method comprising:
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a) providing a micromirror array arranged in an illumination system, the micromirror array comprising M micromirrors, each micromirror being tiltable through a respective tilt angle about two tilt axes; b) driving k=1, 2, . . . , M individual micromirrors to switch from a first illumination setting to a second illumination setting, wherein switching between the two illumination settings is completed in less than 50 milliseconds for each of the k=1, 2, . . . , M micromirrors.
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30. An illumination system of a microlithographic exposure apparatus, the illumination system comprising:
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a) a micromirror array comprising M micromirrors, each micromirror being tiltable through a respective tilt angle about two tilt axes; and b) drive electronics configured to drive the individual micromirrors, the drive electronics being capable of switching the illumination setting from a first illumination setting to a second illumination setting by driving k=1, 2, . . . , M individual micromirrors so that the switching between the two illumination settings is completed in less than 50 milliseconds for each k=1, 2, . . . , M micromirrors. - View Dependent Claims (31)
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Specification