Optical Wafer Bonding Monitoring With Aberration-Corrected Feedback

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Solution Overview

Problem

Existing methods for monitoring substrate bonding processes, particularly in wafer-to-wafer bonding, lack rapid and effective feedback mechanisms, which are crucial for high-performance and high-volume production in integrated circuit manufacturing.

Innovation Solution

A substrate bonding apparatus equipped with an optical metrology sensor that measures the scattering and reflection of radiation through substrates to be bonded, corrects for optical aberrations, and monitors bonding parameters, enabling real-time monitoring and correction of the bonding process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional monitoring methods are used for substrate bonding, then the bonding process can be performed, but rapid and accurate feedback is not provided, reducing productivity and manufacturing precision

Engineering Contradiction:

Improvebonding process speedVSAvoidbonding parameter monitoring accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements an optical monitoring system that provides real-time feedback during substrate bonding by measuring complex field radiation (amplitude and phase) through the substrates. The system continuously monitors bonding parameters such as substrate position, flatness, and bonding progress, and feeds this information back to control the bonding process, enabling rapid and accurate adjustments to maintain optimal bonding conditions.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces conventional mechanical or contact-based monitoring methods with optical measurement techniques. By using optical radiation to measure the complex field through the substrates, the system achieves non-contact, rapid, and precise measurement of bonding parameters without mechanical interference, thereby improving both productivity and measurement precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Speed

If optical radiation is used to monitor bonding through substrates, then rapid feedback is provided, but optical aberrations occur, degrading measurement precision

Engineering Contradiction:

Improvefeedback speedVSAvoidbonding parameter measurement accuracy

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The system uses optical feedback to continuously monitor bonding parameters in real-time. By measuring the complex field radiation that has passed through the substrates, the system provides rapid feedback on substrate position, flatness, and bonding progress, enabling quick adjustments while maintaining measurement accuracy through continuous optimization.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent measures the complex field of radiation, which includes both amplitude and phase information. By utilizing phase information in addition to amplitude, the system can extract more precise bonding parameters and compensate for optical aberrations, thereby maintaining high measurement precision while achieving rapid feedback through optical methods.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If complex field measurement is implemented, then accurate bonding parameter monitoring is achieved, but device complexity increases

Engineering Contradiction:

Improvebonding parameter measurement accuracyVSAvoidmonitoring system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The optical monitoring system is designed to perform multiple functions using a single integrated apparatus. The same optical system measures both amplitude and phase of the complex field, enabling simultaneous monitoring of multiple bonding parameters (substrate position, flatness, bonding progress) without requiring separate measurement systems, thereby reducing overall device complexity while maintaining high measurement precision.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Provides rapid and accurate feedback for substrate bonding processes, enhancing the precision and efficiency of wafer-to-wafer bonding in integrated circuit manufacturing.

Implementation Method 1

an optical metrology sensor configured to measure a complex field of radiation propagating through a donor substrate and/or acceptor substrate to be bonded, said complex field of radiation the result of scattering and/or reflection of illumination radiation by a target structure

Methodology Applied

Scientific EffectScattering: Scattering

Implementation Method 2

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentEP4704143A1Method and apparatus for monitoring substrate bonding

Publication Date: 2026.03.04 ASML NETHERLANDS BV

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AI summary

There is provided a substrate bonding apparatus comprising: a donor substrate support; an acceptor substrate support, an optical metrology sensor configured to measure a complex field of radiation propagating through a donor substrate and/or acceptor substrate to be bonded, said complex field of radiation the result of scattering and/or reflection of illumination radiation by a target structure comprised on the donor substrate and/or the acceptor substrate; and a controller configured to; correct the measured complex field for optical aberrations; and monitor a bonding parameter of interest based on a corrected complex field.