US 10,474,041 B1 · Digital lithography with extended depth of focus

Abstract

The present disclosure generally relates to lithography devices comprising an autofocus system. The autofocus system is configured to individually focus and adjust a plurality of digital micromirror devices. The autofocus system comprises a single light beam and a diffractive optical element configured to split the single light beam into two or more split beams. The two or more split beams are directed to a beam splitter. The two or more split beams are then reflected off the surface of a substrate to at least one position sensor. The position sensor is configured to measure the position of each of the two or more split beams. At least one digital micromirror device is then individually adjusted based on the measured position to adjust the focus of the at least one digital micromirror device with respect to surface height and tilt variations of the substrate.

Claims20

Dependent claims

An autofocus system, comprising:

a light source configured to output a light beam;
a diffractive optical element disposed adjacent to the light source, the diffractive optical element configured to split the light beam into two or more split beams;
a beam splitter disposed adjacent to the diffractive optical element;
two or more digital micromirror devices disposed adjacent to the beam splitter;
and
at least one position sensor, wherein the two or more split beams form two or more light spots on the at least one position sensor, and wherein the at least one position sensor is configured to measure a position of each of the two or more light spots.

3 more elements

A method of autofocusing two or more digital micromirror devices, comprising:

outputting a light beam by a light source;
splitting the light beam into two or more split beams by a diffractive optical element disposed adjacent to the light source;
reflecting two or more light beams off of a beam splitter, wherein the two or more split beams align with projection fields of two or more digital micromirror devices, the two or more digital micromirror devices being disposed adjacent to the beam splitter;
reflecting the two or more light beams from the beam splitter off of a substrate;
directing the two or more light beams from the substrate to at least one position sensor, wherein the two or more light beams form two or more light spots on the at least one position sensor;
measuring a position of each of the two or more light spots using the at least one position sensor;
and
adjusting, individually, at least one digital micromirror device of the two or more digital micromirror devices based on the measured position of each of the two or more light spots.

5 more elements

Dependencies are inferred from the claim text.

Digital lithography with extended depth of focus

Life of this patent

Digital lithography with extended depth of focus

Life of this patent

Abstract

Claims20