Remote Optical Temperature Sensing for High-Voltage Substrate Stages

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Solution Overview

Problem

In semiconductor processes, accurately monitoring substrate temperature is crucial for defect inspection, but conventional temperature sensors are cumbersome due to voltage applications, especially in electron beam inspection systems where high voltages are used, leading to interference and contamination risks.

Innovation Solution

A stage apparatus with a remote temperature sensor using a passive temperature sensing element that measures the temperature of the object table or object without mechanical connections, employing a measurement beam and detector to determine temperature based on optical characteristics, reducing interference and allowing voltage application without electrical insulation issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional temperature sensors are used to measure substrate temperature, then temperature monitoring is achieved, but electrical insulation issues and contamination risks arise due to voltage application

Engineering Contradiction:

Improvetemperature measurement accuracyVSAvoidelectrical insulation reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent replaces conventional electrical temperature sensors with an optical temperature sensing system that uses a measurement beam and detector to measure temperature based on optical characteristics of the substrate table, eliminating electrical insulation issues and contamination risks while maintaining measurement accuracy

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an optical intermediary (measurement beam) that transfers temperature information from the substrate table to the detector without requiring direct electrical contact, thereby resolving the contradiction between measurement accuracy and electrical insulation reliability

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If conventional temperature sensors are mechanically connected to the substrate table, then temperature measurement is possible, but contamination risks increase

Engineering Contradiction:

Improvetemperature measurement capabilityVSAvoidcontamination risk

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces mechanical connections with an optical measurement system that determines temperature through optical characteristics without physical contact between the sensing element and substrate table, eliminating contamination risks while preserving measurement precision

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts the temperature sensing function from the mechanical substrate table structure by using a remote optical sensor system, separating the measurement function from the substrate table to avoid contamination

Inventive Principle:

Principle #2Taking out (Extraction)

3Productivity

If voltage is applied to the substrate table for electron beam inspection, then inspection functionality is enabled, but temperature sensor operation becomes cumbersome

Engineering Contradiction:

Improveinspection functionalityVSAvoidtemperature sensor operation

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The patent replaces electrical temperature sensing with an optical sensing system that measures temperature through optical characteristics unaffected by the high voltage applied to the substrate table, enabling both inspection functionality and temperature monitoring to operate simultaneously without interference

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses optical radiation as an intermediary that can penetrate or bypass the electrical field environment, allowing temperature measurement to proceed independently of the voltage application required for electron beam inspection

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Enables accurate and interference-free temperature measurement of substrates during electron beam inspection, facilitating precise defect monitoring and process control while avoiding contamination risks associated with electrical insulation.

Implementation Method 1

employing a measurement beam and detector to determine temperature based on optical characteristics

Methodology Applied

Scientific EffectOptical characteristics detection: Reflection

Data Source

PatentUS12051607B2Substrate positioning device with remote temperature sensor

Publication Date: 2024.07.30 ASML NETHERLANDS BV

AI summary

A stage apparatus including: an object table configured to hold an object; a positioning device configured to position the object table and the object held by the object table; and a remote temperature sensor configured to measure a temperature of the object table and/or the object, wherein the remote temperature sensor comprises a passive temperature sensing element.