Imprint Overlay Control Using Constrained Error Compensation

Solution Overview

Problem

Existing nano-fabrication techniques face challenges in achieving precise overlay alignment of pattern layers due to distortions and height variations in substrates, leading to reduced production yields and impaired device functionality.

Innovation Solution

A method and system for generating control values using constrained optimization to minimize residual overlay errors by adjusting in-plane and out-of-plane control values, including actuator, heater, and drop-pattern controls, to compensate for distortions and height variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional nanoimprint lithography is used without advanced overlay control, then the process is simpler and faster, but overlay alignment accuracy deteriorates due to substrate distortions and height variations

Engineering Contradiction:

Improveoverlay alignment accuracyVSAvoidcontrol system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary measurements of substrate height variations and distortion patterns before the imprint process. Based on these measurements, it pre-calculates and applies compensation values to the control parameters, adjusting the imprint head position and force distribution in advance to counteract expected overlay errors

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback loop where overlay errors are measured after pattern transfer, then fed back to update the relationship values between control values and overlay corrections. This iterative feedback mechanism continuously refines the control model to improve overlay accuracy in subsequent imprints

Inventive Principle:

Principle #23Feedback

2Manufacturing precision

If substrate height variations are not compensated, then the process is faster, but overlay alignment accuracy and production yields deteriorate

Engineering Contradiction:

Improveoverlay alignment accuracyVSAvoidproduction throughput

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The system performs preliminary measurements of substrate height variations and distortion patterns before the imprint process. Based on these measurements, it pre-calculates and applies compensation values to the control parameters, adjusting the imprint head position and force distribution in advance to counteract expected overlay errors

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts multiple control parameters including imprint head position (x, y, z coordinates), tilt angles, and force distribution based on measured substrate variations. These parameter changes are calculated to compensate for height variations and distortion patterns, maintaining overlay accuracy across wafers with different relief patterns

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If relationship values between control values and overlay corrections are not established, then the process is simpler, but overlay error correction capability deteriorates

Engineering Contradiction:

Improveoverlay error correctionVSAvoidmeasurement and calibration complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary measurements of substrate height variations and distortion patterns before the imprint process. Based on these measurements, it pre-calculates and applies compensation values to the control parameters, adjusting the imprint head position and force distribution in advance to counteract expected overlay errors

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback loop where overlay errors are measured after pattern transfer, then fed back to update the relationship values between control values and overlay corrections. This iterative feedback mechanism continuously refines the control model to improve overlay accuracy in subsequent imprints

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12498634B2System and method for generating control values for overlay control of an imprint tool

Publication Date: 2025.12.16 CANON KK

AI summary

Some devices, systems, and methods obtain a set of relationship values, wherein the set of relationship values indicates relationships between control values for an imprint apparatus and corresponding overlay corrections; and estimate a set of control values based on a constrained optimization that uses the set of relationship values such that the set of control values globally minimizes a residual overlay error while the set of control values is maintained within a set of operating constraints, wherein the set of control values includes a set of in-plane control values that are in a plane and a set of out-of-plane control values that are out of the plane, wherein the plane is parallel to a template-substrate interface.