Methods and apparatus for correcting lithography systems

A non-transitory computer-readable medium comprising instructions that, when executed, cause a lithography system to:

• direct first light beams toward a reflective surface of a first substrate using a spatial light modulator of an optical module;
• collect the first light beams that reflect off of the reflective surface through at least an objective lens of the optical module;
• direct the first light beams collected through at least the objective lens toward a camera of the optical module using a beam splitter of the optical module;
• take a plurality of first images, using the camera, of the first light beams directed toward the camera;
• direct second light beams at an oblique angle toward a patterned surface of a second substrate using an illumination source disposed below the objective lens;
• collect the second light beams that scatter off of the patterned surface through at least the objective lens;
• direct the second light beams collected through at least the objective lens toward the camera using the beam splitter;
• take a plurality of second images, using the camera, of the second light beams directed toward the camera;
• and
• determine a tip correction, a tilt correction, and an optimal vertical position for the optical module.

A non-transitory computer-readable medium comprising instructions that, when executed, cause a lithography system to:

• direct brightfield light beams toward a reflective surface of a first substrate using a spatial light modulator of an optical module;
• take a plurality of brightfield images, using a camera of the optical module, of reflected brightfield light beams that reflect off of the reflective surface;
• direct darkfield light beams toward a patterned surface of a second substrate;
• take a plurality of darkfield images, using the camera, of scattered darkfield light beams that scatter off of the patterned surface;
• and
• determine a tip correction, a tilt correction, and an optimal vertical position for the optical module.