Method and apparatus for exposing photoresists using programmable masks
AssigneePixelligent Technologies, LLC
InventorsAndrew Case, Gregory D. Cooper, Erin Fleet
Life of this patent
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Abstract
Method and apparatus for exposing photo resists using programmable masks increases imaging resolution to provide fully dense integrated circuit patterns made of very small features on photoresist-coated silicon wafers by optical lithography. Small features are created by means of overlap exposure with either programmable or conventional masks. Blocking photoresists responding differently to two different wavelengths of light, two-color photoresists requiring two wavelengths of light to change solubility, and two-photon photoresists which change solubility only by absorbing two photons at a time may be used.
Claims17
A method of catalyzing a non-integrating resist on a substrate comprising:
- (a) illuminating a resist with a first illumination pattern;
- (b) illuminating said resist with a second illumination pattern that at least partially but not entirely overlaps said first illumination pattern in predetermined overlap regions;
- (c) waiting at least a predetermined relaxation time;
- (d) developing said illuminated resist;
- wherein the overlap regions of said resist acquire a different solubility from other regions of said resist.
A method of catalyzing a non-integrating resist on a substrate with a photomask comprising:
- (a) illuminating a resist with a first illumination pattern;
- (b) illuminating said resist with a second illumination pattern that at least partially but not entirely overlaps said first illumination pattern in predetermined overlap regions;
- (c) waiting at least a predetermined relaxation time;
- (d) moving said substrate relative to said photomask, (e) repeating steps a) through d) as many times as necessary to expose a complete pattern;
- and
- (f) developing said illuminated resist;
- wherein the overlap regions of said resist acquire a different solubility from other regions of said resist.
A method of inscribing a complete pattern on a non-integrating photoresist on a substrate by means of a series of exposures, comprising:
- (a) programming a programmable mask with a pattern, said programmable mask having a plurality of pixels, each of said pixels producing a light intensity distribution at said photoresist consisting of a central peak with relatively high intensity and side lobes with relatively low intensities;
- b) illuminating said photoresist with said programmable mask for a duration of time such that the light from said central peaks exceeds the exposure threshold of said photoresist and the light from said side lobes does not exceed said exposure threshold;
- c) moving said substrate relative to said programmable mask;
- d) reprogramming said programmable mask with a different pattern;
- e) illuminating said photoresist again, such that the elapsed time between exposures is equal to or greater than a predetermined relaxation time;
- f) repeating steps c) through e) as many times as necessary to expose a complete pattern;
- and
- g) developing said photoresist.
A method of catalyzing a photoresist on a substrate comprising:
- a) illuminating said photoresist with a first predetermined pattern of illumination at a first wavelength;
- and
- b) illuminating said photoresist with a second predetermined pattern of illumination at a second wavelength different from said first wavelength;
- and
- c) developing said photoresist;
- wherein illumination of said photoresist at said first wavelength blocks persistent change within said photoresist that would otherwise occur in response to illumination at said second wavelength.
A method of inscribing a complete pattern with one or more photomasks by means of series of exposures onto photoresist which requires illumination with a first and second wavelength comprising:
- a) illuminating said photoresist at said first wavelength with a first illumination pattern;
- b) illuminating said photoresist at said second wavelength with a second illumination pattern that at least partially but not entirely overlaps said first illumination pattern in predetermined overlap regions;
- c) moving said substrate relative to said photomask or photomasks;
- d) waiting for at least some predetermined relaxation time;
- e) repeating steps a) through d) as many times as necessary to expose a complete pattern;
- and
- (f) developing said exposed photoresist;
- wherein the overlap regions of said photoresist acquire a different solubility from other regions of said photoresist.
A method of inscribing a complete pattern on an integrating two-photon photoresist by means of a series of illuminations comprising:
- (a) programming a programmable mask with a pattern, said programmable mask having a plurality of pixels, each of said pixels producing a light intensity distribution at said photoresist consisting of a central peak with relatively high intensity and side lobes with relatively low intensities;
- b) illuminating said photoresist with said programmable mask;
- c) moving said substrate relative to said programmable mask;
- d) repeating steps a) through c) as many times as necessary to expose a complete pattern;
- and
- e) developing said illuminated photoresist.
Dependencies are inferred from the claim text.