Method for photolithography using multiple illuminations and a single fine feature mask
AssigneeMassachusetts Institute of Technology
InventorsMichael Fritze, Brian Tyrrell
Life of this patent
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Abstract
A method forms a feature pattern on a substrate by exposing the substrate, using a mask having a pattern of features thereon, with illumination having a first set of settings. The substrate is exposed a second time, using the same mask having the pattern of features thereon, with illumination having a second set of settings. The mask having the pattern of features thereon remains stationary between the two illumination exposures of the substrate.
Claims37
A method of forming a feature pattern on a substrate, comprising:
- (a) exposing the substrate, using a mask having a pattern of features thereon, with illumination from an illuminator;
- (b) adding a phase shifter to the illuminator;
- and
- (c) exposing the substrate, using the same mask having the pattern of features thereon, with illumination from the illuminator having the phase shifter, the phase shifter enabling the pattern upon substrate to be shifted in Cartesian space with fine resolution.
A method of forming an interdigitated pattern on a substrate, comprising:
- (a) exposing the substrate, using a mask having a pattern of features thereon, with illumination from an illuminator;
- (b) adding a phase shifter element to an optical path of the illuminator;
- and
- (c) exposing the substrate, using the same mask having the pattern of features thereon, with illumination from the illuminator having the phase shifter element in the optical path thereof, the phase shifter shifting the pattern upon substrate in Cartesian space to produce the interdigitated pattern.
A method of forming a feature pattern on a substrate, comprising:
- (a) exposing the substrate, using a first mask having a pattern of features thereon, with illumination from an illuminator;
- and
- (b) exposing the substrate, using the first mask having a pattern of features thereon, with illumination from the illuminator having a phase shifter element in the optical path thereof, the phase shifter element enabling the pattern to be aligned upon substrate in Cartesian space with fine resolution.
An illuminator for a lithography apparatus, comprising:
- a light source to provide illumination;
- and
- illumination parameter modifying means for varying illumination parameters between subsequent exposures of a same mask;
- said illumination parameter modifying means including a phase shifter to impart an illumination wavefront phase.
A photolithographic exposure system, comprising:
- an illuminator;
- a projection optics system;
- and
- a substrate stage;
- said illuminator including,
- a light source,
- a phase shifter element to align a pattern in Cartesian space, and
- illumination parameter modifying means for varying illumination parameters between subsequent exposures of a same mask.
Dependencies are inferred from the claim text.