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US 2025/0053105 A1Published application
Systems and methods for monitoring spatial light modulator (slm) flare
AssigneeNikon Corporation
InventorsDonis G. FLAGELLO, Shiang-Lung KOO, Bausan YUAN
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Abstract
The problem of the presence of excess flare in maskless photolithography systems is addressed by systems and methods that utilize an aerial imaging system to monitor flare associated with the maskless photolithography systems.
Claims28
A system for monitoring spatial light modulator (SLM) flare in a maskless photolithography system, comprising:
- a stage configured to support an SLM and a reference plate, the stage movable between:
- a first position in which the SLM receives source light, imparts an SLM pattern thereon, and projects spatially modulated light based on the SLM pattern, the spatially modulated light comprising a first flare pattern associated with the SLM;
- and
- a second position in which the reference plate receives the source light, imparts a reference modulation pattern thereon, and projects reference modulated light based on the reference modulation pattern, the reference modulated light comprising a second flare pattern associated with the reference plate;
- a projection lens configured to:
- when the stage is in the first position, receive the spatially modulated light and project a first image corresponding to the spatially modulated light;
- when the stage is in the second position, receive the reference modulated light and project a second image corresponding to the reference modulated light;
- an aerial imaging system configured to:
- when the stage is in the first position, receive the first image and output a first signal corresponding thereto;
- and
- when the stage is in the second position, receive the second image and output a second signal corresponding thereto;
- and
- a controller operably coupled to the stage and to the aerial imaging system, the controller configured to:
- (a) direct the stage to move to the first position;
- (b) receive the first signal;
- (c) direct the stage to move to the second position;
- (d) receive the second signal;
- and
- (e) determine a third flare pattern associated with SLM errors based on a difference between the first signal and the second signal.
16 more elements
A method for monitoring spatial light modulator (SLM) flare in a maskless photolithography system, comprising:
- (a) projecting source light to an SLM, thereby imparting an SLM pattern thereon and projecting spatially modulated light based on the SLM pattern, the spatially modulated light comprising a first flare pattern associated with the SLM;
- (b) using a projection lens to receive the spatially modulated light and to project a first image corresponding to the spatially modulated light;
- (c) using an aerial imaging system to receive the first image and to output a first signal corresponding thereto;
- (d) projecting the source light to a reference plate, thereby imparting a reference modulate pattern thereon and projecting reference modulated light based on the reference modulation pattern, the reference modulated light comprising a second flare pattern associated with the reference plate;
- (e) using the projection lens to receive the reference modulated light and to project a second image corresponding to the reference modulated light;
- (f) using the aerial imaging system to receive the second image and to output a second signal corresponding thereto;
- and
- (g) determining a third flare pattern associated with SLM errors based on a difference between the first signal and the second signal.
5 more elements
An exposure apparatus comprising:
- an illumination optical system configured to illuminate a spatial light modulator (SLM) which has a plurality of SLM elements having a reflecting surface disposed on a disposition plane;
- a projection optical system configured to project light from the SLM to a workpiece;
- a reference member having a reference modulation pattern;
- a position changing apparatus configured to change a positional relationship among the SLM, the reference member, and the projection optical system to either a first positional relationship in which a light from the illumination optical system enters in the projection optical system via the SLM and a second positional relationship in which a light from the illumination optical system enters in the projection optical system via the reference member;
- and
- a detection apparatus configured to detect a light from the SLM or the reference member via the projection optical system.
3 more elements
An exposure method comprising:
- illuminating a spatial light modulator (SLM) which has a plurality of SLM having a reflecting surface disposed on a disposition plane;
- using a projection optical system to project a light from the SLM to a workpiece;
- setting a positional relationship between the SLM and the projection optical system to a first positional relationship in which a light from the SLM enters in the projection optical system;
- outputting a first output by detecting a light from the SLM via the projection optical system in the first positional relationship;
- setting a positional relationship between a reference member having a reference modulation pattern and the projection optical system to a second positional relationship in which a light from the reference member enters in the projection optical system;
- and
- outputting a second output by detecting a light from the SLM via the projection optical system in the second positional relationship.
4 more elements
Dependencies are inferred from the claim text.