Wavelength-Tunable Pattern Measurement for Accurate Substrate Alignment

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Solution Overview

Problem

Existing substrate processing apparatuses face challenges in accurately measuring pattern positions and relative positions between layers due to wavelength shifts and intensity variations in light, leading to errors in detection signals.

Innovation Solution

A measuring device with a wavelength variable unit that adjusts its position based on wavelength and intensity characteristic information to ensure the transmission of light with a desired wavelength, reducing wavelength shifts and enhancing signal intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a filter is driven to vary the wavelength of light, then the wavelength can be adjusted according to processing steps, but the filter position may shift from the target position causing wavelength errors

Engineering Contradiction:

Improvewavelength adjustment capabilityVSAvoidwavelength accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where the actual position of the wavelength variable unit is detected and compared with the target position. When a deviation is detected, the system automatically adjusts the unit to correct the position error, ensuring the light wavelength remains accurate despite external disturbances or mechanical drift.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces pure mechanical positioning with a hybrid system that incorporates optical detection and automated control. Instead of relying solely on mechanical precision, the system uses optical fields for detection and electronic control for positioning, reducing the impact of mechanical errors on wavelength accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If the incident position of light on the wavelength variable unit varies, then different wavelengths can be selected, but wavelength shifts occur leading to detection errors

Engineering Contradiction:

Improvewavelength selection rangeVSAvoidpattern position measurement accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system continuously monitors the actual position of the wavelength variable unit and compares it with the target position. When wavelength shifts are detected, the feedback mechanism automatically adjusts the unit's position to correct the error, ensuring consistent and accurate pattern position measurements across different processing steps.

Inventive Principle:

Principle #23Feedback

3Reliability

If the wavelength of illuminating light is not optimized, then the measurement process is simpler, but the intensity of detected signal decreases and error increases

Engineering Contradiction:

Improvesignal detection reliabilityVSAvoidwavelength control system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The wavelength variable unit is designed to automatically adjust its own position based on detected positional information and pre-stored characteristic data. This self-service capability eliminates the need for complex external control mechanisms, achieving reliable signal detection through automated wavelength optimization while keeping the control system relatively simple.

Inventive Principle:

Principle #25Self-service

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

This approach increases the intensity of detected signals and reduces errors in pattern measurement, improving the accuracy of position measurement on substrates.

Implementation Method 1

a wavelength variable unit configured to vary a spectrum of first light in accordance with an incident position at which the first light is incident to allow the first light to pass therethrough

Methodology Applied

Scientific EffectWavelength selective transmission: Filter (optical)

Implementation Method 2

a moving unit configured to change the incident position by moving the wavelength variable unit

Methodology Applied

Scientific EffectMechanical displacement: Displacement

Data Source

PatentUS12510464B2Measuring device, measuring method, substrate processing apparatus, and method of manufacturing product

Publication Date: 2025.12.30 CANON KK

AI summary

A measuring device for measuring a position of a pattern includes a wavelength variable unit configured to vary a spectrum of first light in accordance with an incident position at which the first light is incident to allow the first light to pass therethrough, and a moving unit configured to change the incident position by moving the wavelength variable unit. The wavelength variable unit is moved to a position based on wavelength characteristic information and intensity characteristic information, the wavelength characteristic information indicating a relationship between the position of the wavelength variable unit and a wavelength of the first light transmitted through the wavelength variable unit, the intensity characteristic information indicating a relationship between the position of the wavelength variable unit and an intensity of second light from the pattern illuminated with the first light transmitted through the wavelength variable unit.