System and method for lithography with leveling sensor
First Claim
Patent Images
1. A lithography system, comprising:
- a radiation source for providing radiation energy;
a reticle stage configured to hold a reticle;
a substrate stage configured to hold a substrate and operable to move relative to the reticle stage;
an imaging lens module configured to direct the radiation energy onto the substrate to form an image of the reticle;
a leveling signal source configured to direct and scan a leveling signal to an exposure field of the reticle secured on the stage, wherein the leveling signal source is secured to the substrate stage such that the leveling signal source moves with the substrate stage relative to the reticle stage;
a leveling sensor configured to receive the leveling signal from the exposure field of the reticle secured on the reticle stage, wherein the leveling sensor is secured to the substrate stage such that the leveling sensor moves with the substrate stage relative to the reticle stage;
a leveling analysis module operable to receive the leveling signal from the leveling sensor, calculate at least one of a reticle flatness measurement and a reticle overlay error measurement for the reticle based on the received leveling signal, generate a first control parameter associated with a focus length based on at least one of the reticle flatness measurement and the reticle overlay error measurement, and generate a second control parameter associated with a tilt angle of the reticle based on at least one of the reticle flatness measurement and the reticle overlay error measurement;
a control module operable to receive the first and second control parameters from the leveling analysis module and move the reticle stage based on the first control parameter and tilt the reticle stage based on the second control parameter; and
wherein the leveling signal source and the leveling sensor are secured to an upper surface of the substrate stage.
2 Assignments
0 Petitions
Accused Products
Abstract
Disclosed is a lithography system. The lithography system includes a radiation source for providing radiation energy; a reticle stage configured to hold a reticle; an imaging lens module configured to direct the radiation energy onto a substrate to form an image of the reticle; and a leveling sensor configured to receive a leveling signal from an exposure field of the reticle secured on the reticle stage.
17 Citations
20 Claims
-
1. A lithography system, comprising:
-
a radiation source for providing radiation energy; a reticle stage configured to hold a reticle; a substrate stage configured to hold a substrate and operable to move relative to the reticle stage; an imaging lens module configured to direct the radiation energy onto the substrate to form an image of the reticle; a leveling signal source configured to direct and scan a leveling signal to an exposure field of the reticle secured on the stage, wherein the leveling signal source is secured to the substrate stage such that the leveling signal source moves with the substrate stage relative to the reticle stage; a leveling sensor configured to receive the leveling signal from the exposure field of the reticle secured on the reticle stage, wherein the leveling sensor is secured to the substrate stage such that the leveling sensor moves with the substrate stage relative to the reticle stage; a leveling analysis module operable to receive the leveling signal from the leveling sensor, calculate at least one of a reticle flatness measurement and a reticle overlay error measurement for the reticle based on the received leveling signal, generate a first control parameter associated with a focus length based on at least one of the reticle flatness measurement and the reticle overlay error measurement, and generate a second control parameter associated with a tilt angle of the reticle based on at least one of the reticle flatness measurement and the reticle overlay error measurement; a control module operable to receive the first and second control parameters from the leveling analysis module and move the reticle stage based on the first control parameter and tilt the reticle stage based on the second control parameter; and wherein the leveling signal source and the leveling sensor are secured to an upper surface of the substrate stage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A lithography system, comprising:
-
a radiation source for providing radiation energy; a reticle stage configured to hold a reticle having a circuit pattern within an exposure field; a substrate stage configured to secure a substrate to an upper surface of the substrate stage; an optical module configured to direct the radiation energy onto the substrate to form an image of the circuit pattern; a leveling signal source to provide a first leveling signal that includes a first beam and a second beam, the leveling signal source configured to direct the first beam to the exposure field of the reticle and configured to direct the second beam directly at a leveling sensor; the leveling sensor configured to receive the first beam reflected from the reticle and the second beam directly from the leveling signal source, wherein the leveling sensor recombines the first and second beams to form a second leveling signal, wherein the leveling signal source and the leveling sensor are secured to the upper surface of the substrate stage; and a leveling analysis module operable to analyze the second leveling signal for reticle leveling; and a control module coupled to the leveling analysis module and configured to control the reticle stage for tilting and focusing according to feedback from the leveling analysis module. - View Dependent Claims (11, 12, 13)
-
-
14. A method for a lithography system, comprising:
-
securing a reticle on a reticle stage of the lithography system, wherein the reticle includes a circuit pattern within an exposure field; after securing the reticle on the reticle stage, scanning the reticle using a leveling signal over the exposure field of the reticle for reticle leveling while the reticle is secured on the reticle stage, wherein scanning the reticle using the leveling signal includes moving a leveling signal source producing the leveling signal while scanning the reticle, wherein the leveling signal source is operable to move in a first direction and is also operable to move in a second direction perpendicular to the first direction; after scanning the reticle, generating a first control parameter associated with a focus length and a second control parameter associated with a tilt angle of the reticle based on the leveling signal; moving the reticle stage based on the first control parameter and tilting the reticle stage based on the second control parameter; and after moving the reticle stage based on the first control parameter and tilting the reticle stage based on the second control parameter, applying radiation energy from a radiation source of the lithography system to form an image of the circuit pattern of the reticle within the exposure field on a substrate. - View Dependent Claims (15, 16, 17, 18, 19, 20)
-
Specification