Dynamic illumination uniformity and shape control for lithography
First Claim
1. A subsystem for a lithographic tool, comprising at least one array of controllable tilting mirrors placed in either an image reticle plane or a conjugate image plane to provide dynamic control of an illumination beam through an exposure field.
1 Assignment
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Accused Products
Abstract
A subsystem for an exposure apparatus has at least one array of tilting mirrors placed in either an image reticle plane or a conjugate image plane to provide dynamic control of an illumination beam through an exposure field. In the system, an optical subsystem and a plurality of mirrors directs light to a reticle and a sensor senses the illumination distribution of the light at a wafer stage. When the at least one array of tilting mirrors is placed in the image reticle plane, a control is used to interpolate data of the illumination distribution sensed by the sensor, and then control movement of at least one mirror of the array of mirrors based on the interpolated data.
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Citations
29 Claims
- 1. A subsystem for a lithographic tool, comprising at least one array of controllable tilting mirrors placed in either an image reticle plane or a conjugate image plane to provide dynamic control of an illumination beam through an exposure field.
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16. A subsystem for a lithographic tool, comprising:
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an optical subsystem and a plurality of mirrors directing light to a reticle;
an array of tilting mirrors placed in an image reticle plane of the light;
a sensor for sensing the illumination distribution of the light at a wafer stage; and
a control for interpolating data of the illumination distribution sensed by the sensor, and controlling movement of at least one mirror of the array of mirrors based on the interpolated data. - View Dependent Claims (17, 18)
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19. A subsystem for a lithographic tool, comprising:
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an optical subsystem and a plurality of mirrors directing light to an exposure field; and
an array of tilting mirrors placed in a conjugate image plane of the light to control the source shape to modulate the frequency plane of an image.
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20. A method for reducing illumination non-uniformity, comprising the steps of:
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illuminating an exposure field with light;
measuring brightness of the light throughout the exposure field;
interpolating the measured brightness to provide data of illumination uniformity over the exposure field; and
adjusting at least one mirror element based on the data to manipulate the light thereby reducing illumination non-uniformity as measured in the measuring step. - View Dependent Claims (21, 22, 23)
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24. An exposure apparatus, comprising:
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an illumination system that projects radiant energy on a reticle R that is supported by and scanned using a wafer positioning stage;
at least one linear motor that positions the wafer positioning stage; and
at least one array of tilting mirrors placed in either an image reticle plane or a conjugate image plane of the illumination system to provide dynamic control of an illumination beam through an exposure field. - View Dependent Claims (25, 26, 27, 28, 29)
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Specification