Managing multi-objective alignments for imprinting

Patent metadata

Field	Value
Publication number	US-12204258-B2
Application number	US-202118014327-A
Country	US
Kind code	B2
Filing date	Aug 6, 2021
Priority date	Aug 7, 2020
Publication date	Jan 21, 2025
Grant date	Jan 21, 2025

Abstract

Systems and methods for managing multi-objective alignments in imprinting (e.g., single-sided or double-sided) are provided. An example system includes rollers for moving a template roll, a stage for holding a substrate, a dispenser for dispensing resist on the substrate, a light source for curing the resist to form an imprint on the substrate when a template of the template roll is pressed into the resist on the substrate, a first inspection system for registering a fiducial mark of the template to determine a template offset, a second inspection system for registering the imprint on the substrate to determine a wafer registration offset between a target location and an actual location of the imprint, and a controller for controlling to move the substrate with the resist below the template based on the template offset, and determine an overlay bias of the imprint on the substrate based on the wafer registration offset.

First claim

What is claimed is:

1. An imprinting method comprising:
drawing a template roll along rollers, the template roll comprising a template field having a template and a template fiducial mark of the template;
measuring the template fiducial mark of the template to determine a template offset;
moving a substrate with resist on a stage to be below the template of the template roll based on an imprinting alignment offset, the imprinting alignment offset being at least partially determined based on the template offset, the resist being on a first side of the substrate;
pressing the template of the template roll into the resist on the substrate;
curing the resist to form an imprint on the substrate, the imprint having an imprinted feature corresponding to the template and an imprint fiducial mark corresponding to the template fiducial mark of the template;
measuring the imprint fiducial mark of the imprint to determine a wafer registration offset between a target fiducial location and an actual fiducial location associated with the imprint fiducial mark; and
determining an overlay bias of the imprint on the first side of the substrate at least partially based on the wafer registration offset.

2. The imprinting method of claim 1 , wherein the imprinting alignment offset is at least partially determined based on at least one of a loading offset or an imprint nominal correction, and wherein the loading offset is determined at least partially based on a previous imprinting process on another substrate.

3. The imprinting method of claim 2 , wherein determining an overlay bias of the imprint on the substrate comprises:
determining the overlay bias to be the wafer registration offset minus the loading offset.

4. The imprinting method of claim 2 , further comprising:
moving the substrate on the stage to be below a resist dispenser according to a dispensing alignment offset that is at least partially determined based on at least one of the loading offset, or a dispense offset, or a dispense nominal correction,
wherein the dispense offset provides a correction for imprint to resist centering from a nominal dispense location.

5. The imprinting method of claim 2 , further comprising:
measuring the image of the substrate with the imprint to determine at least one of an imprint to substrate image offset or an imprint to resist image offset;
updating the dispensing alignment offset based on the at least one of the imprint to substrate image offset or the imprint to resist image offset;
iteratively imprinting a second substrate with the template of the template roll using the updated dispensing alignment offset;
updating the loading offset based on the imprint to substrate image offset; and
updating the dispense offset based on the imprint to resist image offset,
wherein the dispensing alignment offset is updated based on at least one of the updated loading offset or the updated dispense offset.

6. The imprinting method of claim 5 , wherein measuring the image of the substrate with the imprint to determine at least one of an imprint to substrate image offset or an imprint to resist image offset comprises:
measuring the image of the substrate with the imprint by using an inspection system.

7. The imprinting method of claim 1 , wherein the substrate is held on the stage via a chuck, wherein the chuck comprises a measurement area that has a better image contrast than other areas of the chuck, and wherein the substrate is held on the chuck with the imprint fiducial mark of the imprint on the substrate within the measurement area.

8. The imprinting method of claim 1 , wherein measuring the template fiducial mark of the template to determine a template offset comprises:
measuring the template fiducial mark of the template using an upward looking inspection system, wherein the upward looking inspection system is positioned on the stage,
wherein the template field comprises a plurality of fiducial marks for one or more templates, and
wherein the upward looking inspection system comprises a plurality of cameras, each of the plurality of cameras being configured to capture an image including a different corresponding fiducial mark of the plurality of fiducial marks for the one or more templates.

9. The imprinting method of claim 1 , wherein measuring the imprint fiducial mark of the imprint to determine a wafer registration offset comprises:
measuring the imprint fiducial mark of the imprint using a downward looking inspection system that is registered in a coordinate system based on the stage,
wherein the stage is configured to hold one or more substrates with one or more imprints, and
wherein the downward looking inspection system comprises a plurality of cameras, each of the plurality of cameras being configured to capture an image including a different corresponding fiducial mark of the one or more imprints on the one or more substrates.

10. The imprinting method of claim 1 , wherein measuring the template fiducial mark of the template to determine a template offset comprises: registering the template fiducial mark of the template in a coordinate system, and
wherein measuring the imprint fiducial mark of the imprint to determine a wafer registration offset comprises: registering the imprint fiducial mark in the coordinate system,
wherein the coordinate system is based on the stage, and wherein the coordinate system is an XYT coordinate system that has an X direction, a Y direction, and a theta direction.

11. The imprinting method of claim 1 , wherein moving a substrate with resist on a stage to be below the template of the template roll based on an imprinting alignment offset comprises:
controlling a moving speed of the stage holding the substrate relative to a drawing speed of the template roll such that the template of the template roll is aligned with the substrate based on the imprinting alignment offset.

12. The imprinting method of claim 1 , further comprising:
flipping the substrate with the imprint and loading the flipped substrate on the stage with the first side facing towards the stage and a second side facing away from the stage, the second side being opposite to the first side;
measuring a flipped imprint fiducial mark of the flipped imprint to determine a second wafer registration offset between a second target fiducial location and a second actual fiducial location associated with the flipped imprint fiducial mark;
measuring a second template fiducial mark of a second template in the template field of the template roll to determine a second template offset;
moving the flipped substrate with second resist on the second side to be below the second template in the template field of the template roll based on a second imprinting alignment offset, the second imprinting alignment offset being determined based on the second template offset, the second wafer registration offset, and the overlay bias;
pressing the second template of the template roll into the second resist on the flipped substrate;
curing the second resist to form a second imprint on the second side, the second imprint having a second imprinted feature corresponding to the second template and a second imprint fiducial mark corresponding to the second template fiducial mark of the second template;
measuring the flipped imprint fiducial mark of the flipped imprint on the first side and the second imprint fiducial mark of the second imprint on the second side to determine a double-sided overlay error between a target fiducial offset and an actual fiducial offset associated with the flipped imprint fiducial mark and the second imprint fiducial mark; and
determining a double-sided overlay bias be

Assignees

• Magic Leap Inc

Inventors

• Sevier Jeremy Lee
• Sadam Satish
• Imhof Joseph Michael
• Luo Kang
• Wang Kangkang
• Patterson Roy Matthew
• Xue Qizhen
• Best Brett William
• Carden Charles Scott
• Shafran Matthew S
• Miller Michael Nevin

Classifications

• G03F9/7046

  Strategy, e.g. mark, sensor or wavelength selection · CPC title

• G03F9/7011

  Pre-exposure scan; original with original holder alignment; Prealignment, i.e. workpiece with workpiece holder · CPC title

• G03F7/0002 Primary

  Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping · CPC title

• G03F9/7042 Primary

  Alignment for lithographic apparatus using patterning methods other than those involving the exposure to radiation, e.g. by stamping or imprinting (non-exposure lithographic processes per se G03F7/0002) · CPC title