Illumination system and method employing a deformable mirror and diffractive optical elements

An illumination system for use in lithography, comprising:

• a source of electromagnetic radiation;
• a deformable mirror;
• actuator means, coupled to the deformable mirror, for changing the surface contour of the deformable mirror;
• profile sensing means for determining an intensity profile of radiation emitted from the source;
• controller means, associated with the profile sensing means and the actuator means, for calculating a surface contour for the deformable mirror and controlling the actuator means;
• and
• diffusive or diffractive optical element, wherein the diffusive or diffractive optical element is a microlens array having individual lens elements of a size no larger than 1/1000 times the size of the desired uniform field,
• whereby radiation from the source is reflected from the deformable mirror and through the diffusive or diffractive optical element resulting in improved global and local radiation intensity uniformity.

An illumination system for use in lithography, comprising:

• a source of electromagnetic radiation;
• a deformable mirror;
• actuator means, coupled to the deformable mirror, for changing the surface contour of the deformable mirror;
• profile sensing means for determining an intensity profile of radiation emitted from the source;
• controller means, associated with the profile sensing means and the actuator means, for calculating a surface contour for the deformable mirror and controlling the actuator means;
• and
• a diffusive or diffractive optical element, wherein the diffusive or diffractive optical element moves less than one unit size in a lateral plane during exposure,
• whereby radiation from the source is reflected from the deformable mirror and through the diffusive or diffractive optical element resulting in improved global and local radiation intensity uniformity.

An illumination system for use in lithography, comprising:

• a source of electromagnetic radiation;
• a deformable mirror;
• actuator means, coupled to the deformable mirror, for changing the surface contour of the deformable mirror;
• profile sensing means for determining an intensity profile of radiation emitted from the source;
• controller means, associated with the profile sensing means and the actuator means, for calculating a surface contour for the deformable mirror and controlling the actuator means;
• and
• a diffusive or diffractive optical element,
• wherein the actuator means further comprises:
• a first row of wire flexures attached along a first longitudinal edge of the deformable mirror;
• a second row of wire flexures attached along a second longitudinal edge of the deformable mirror;
• a first row of actuators attached to the first row of wire flexures;
• a second row of actuators attached to the second row of wire flexures;
• and
• the first and second rows of actuators attached to a base, and
• the first and second row of actuators are controlled by the controller means for deforming the deformable mirror,
• whereby radiation from the source is reflected from the deformable mirror and through the diffusive or diffractive optical element resulting in improved global and local radiation intensity uniformity.

An illumination system for use in photolithography, comprising:

• a laser or radiation beam source;
• a deformable mirror;
• actuator means, associated with the deformable mirror, for changing the surface contour of the deformable mirror;
• profile sensing means for determining an intensity profile of radiation emitted from the laser source;
• controller means, associated with the profile sensing means and the actuator means, for calculating a surface contour for the deformable mirror and controlling the actuator means;
• and
• a first microlens array placed adjacent an illumination plane providing a desired illumination profile to a reticle,
• whereby radiation from the laser source is reflected from the deformable mirror and through the first microlens array resulting in improved global and local radiation intensity uniformity.

A laser illumination system for use in photolithography having an object and image plane, comprising:

• a laser source;
• a deformable mirror;
• actuator means, associated with the deformable mirror, for changing the surface contour of the deformable mirror, the actuator means capable of deforming the surface of the deformable mirror at any one location;
• profile sensing means for determining an intensity profile of radiation emitted from the laser source;
• controller means, associated with the profile sensing means and the actuator means, for calculating a surface contour for the deformable mirror and controlling the actuator means;
• a first movable microlens array having a range of motion along two axes in a single plane of less than 20 microns;
• and
• a second microlens array positioned near the first microlens array,
• the second microlens array placed sufficiently close to a target plane to obtain illumination within the near field diffraction pattern,
• whereby radiation from the laser source is reflected from the deformable mirror and through the first and second microlens arrays resulting in improved global and local radiation intensity uniformity.

An illumination system for use in lithography, comprising;

• a source of electromagnetic radiation;
• a deformable mirror;
• actuator means, coupled to the deformable mirror, for changing the surface contour of the deformable mirror;
• profile sensing means for determining an intensity profile of radiation emitted from the source;
• controller means, associated with the profile sensing means and the actuator means, for calculating a surface contour for the deformable mirror and controlling the actuator means;
• and
• a diffusive or diffractive optical element,
• wherein said diffractive or diffusive optical element is reflective, and whereby the radiation from the source of electromagnetic radiation is reflected rather than transmitted through the diffractive or diffusive optical element resulting in improved global and local radiation intensity uniformity.

An illumination system for use in lithography, comprising:

• a source of electromagnetic radiation;
• a deformable mirror;
• an actuator, said actuator coupled to the deformable mirror and capable of changing the surface contour of the deformable mirror;
• a profile sensor, said profile sensor capable of determining an intensity profile of radiation emitted from the source;
• a controller, said controller coupled to said profile sensor and said actuator, said controller capable of calculating a surface contour for said deformable mirror and controlling the actuator;
• and
• a first diffusive or diffractive optical element placed adjacent an illumination plane,
• whereby radiation from said source is reflected from said deformable mirror and through said first diffusive or diffractive optical element resulting in improved global and local radiation intensity uniformity.