Low numerical aperture alignment
AssigneeOnto Innovation Inc.
InventorJ. Casey Donaher
Life of this patent
Estimating the term…
Abstract
Disclosed herein are examples of a photolithography machine with fast alignment. The machine may include a stage to hold and move a substrate and a projection system to project images on a plurality of exposure regions of the substrate. The machine may also include an alignment system positioned adjacent to the projection system. The alignment system may include a plurality of microscope cameras with a fixed focus, each microscope camera configured to detect a respective fiducial in a respective exposure region of the substrate.
Claims21
A photolithography machine with fast alignment, comprising:
- a stage to hold and move a substrate;
- a projection system to project images on a plurality of exposure regions of the substrate;
- and
- an alignment system positioned adjacent to the projection system, the alignment system including a plurality of microscope cameras with a fixed focus, each microscope camera comprising a single microscope objective to provide a single fixed focus position and each microscope camera configured to detect a respective fiducial in a respective exposure region of the substrate,
- wherein each of the plurality of microscope cameras is configured to detect fiducials at different heights relative to between the stage and the plurality of microscope cameras using the respective fixed focus.
A method to photolithograph a substrate, the method comprising:
- loading the substrate on a stage of a photolithography machine;
- positioning the stage such that an alignment system of the photolithography machine is opposite a first exposure region of the substrate, wherein the alignment system includes a plurality of microscope cameras having a fixed focus, each microscope camera comprising a single microscope objective to provide a single fixed focus position, wherein each microscope camera is configured to detect fiducials at different heights relative to between the stage and the plurality of microscope cameras using the respective fixed focus;
- capturing a first set of images using the plurality of microscope cameras of the first exposure region, each image including a respective fiducial associated with the first exposure region;
- determining alignment correction information for the first exposure region based on the first set of images;
- and
- projecting images on the first exposure region based on the alignment correction information.
An alignment system for a photolithography machine, comprising:
- a supporting structure positioned adjacent to a projection system of the photolithography machine;
- and
- a plurality of microscope cameras coupled to the supporting structure having a fixed focus, each microscope camera comprising a single microscope objective to provide a single fixed focus position and each microscope camera configured to detect a respective fiducial in a respective exposure region of a substrate,
- wherein each of the plurality of microscope cameras is configured to detect fiducials at different heights relative to between the stage and the plurality of microscope cameras using the respective fixed focus.
Dependencies are inferred from the claim text.