Processing Chamber FBG Sensor Wafer for RF-Resistant Temperature Sensing

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Solution Overview

Problem

Conventional luminescent material-based sensors in semiconductor processing chambers face interference from electromagnetic radiation and other limitations, making precise monitoring of temperature and chamber conditions challenging.

Innovation Solution

The use of optical fibers with Fiber Bragg Grating sensors, configured for different center frequencies, to monitor temperature and other conditions within processing chambers, employing a broadband light source for detection and minimizing interference through wavelength selection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If luminescent material-based sensors are used to monitor temperature and chamber conditions, then temperature monitoring capability is provided, but electromagnetic radiation from RF and UV sources causes interference in detection

Engineering Contradiction:

Improvetemperature monitoring precisionVSAvoidelectromagnetic radiation interference

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces luminescent material-based optical sensors with Fiber Bragg Grating (FBG) sensors that use optical fiber technology. FBG sensors reflect specific wavelengths of light based on grating period and refractive index, which are affected by temperature and strain but are immune to electromagnetic radiation interference from RF and UV sources in the processing chamber.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces optical fiber as an intermediary medium to transmit light signals to and from the sensing location. The optical fiber acts as a shielded transmission path that is immune to electromagnetic interference, allowing precise temperature and condition monitoring without direct exposure of sensitive detection elements to the harsh electromagnetic environment.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple sensors are deployed to monitor different conditions in the processing chamber, then monitoring coverage is improved, but system complexity increases

Engineering Contradiction:

Improvemonitoring coverageVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple sensing functions into a single optical fiber by incorporating multiple Fiber Bragg Gratings with different grating periods along the fiber length. Each FBG reflects a different wavelength corresponding to different physical parameters (temperature, strain, pressure), allowing simultaneous multi-parameter monitoring through one integrated sensor assembly rather than multiple separate sensors.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The optical fiber sensor system is designed to perform multiple monitoring functions simultaneously - temperature monitoring, strain measurement, and pressure sensing - all through the same physical medium and detection system, making the system universally applicable to various process parameters without requiring separate dedicated sensors for each parameter.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If conventional luminescent material sensors are used, then temperature detection is possible, but the sensors are sensitive to electromagnetic radiation which causes detection interference

Engineering Contradiction:

Improvedetection reliabilityVSAvoidelectromagnetic radiation sensitivity

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces luminescent material-based detection with FBG-based optical reflection detection. Instead of relying on luminescence emission that can be affected by electromagnetic radiation, the system uses wavelength-specific light reflection from the FBG structure, which is physically immune to RF and UV electromagnetic interference while maintaining temperature sensitivity through grating period changes.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 provides robust, interference-resistant temperature monitoring and condition sensing within semiconductor processing chambers, enhancing precision and reliability.

Implementation Method 1

An optical fiber with Fiber Bragg Grating sensors is located over the platform

Methodology Applied

Scientific EffectFiber Bragg Grating: Bragg Diffraction

Implementation Method 2

A broadband light source is optically transmitted from a light-source based detection system to the optical fiber

Methodology Applied

Scientific EffectOptical fiber transmission: Optical Fibre

Implementation Method 3

Reflected light is optically received from the optical fiber to the light-source based detection system. The reflected light is processed by the light-source based detection system to generate at least temperature related data therefrom

Methodology Applied

Scientific EffectBragg reflection: Bragg Diffraction

Data Source

PatentUS20240186124A1Processing chamber with optical fiber with bragg grating sensors

Publication Date: 2024.06.06 ISENSECLOUD INC

AI summary

An apparatuses relating generally to a test wafer, processing chambers, and method relating generally to monitoring or calibrating a processing chamber, are described. In one such an apparatus for a test wafer, there is a platform. An optical fiber with Fiber Bragg Grating sensors is located over the platform. A layer of material is located over the platform and over the optical fiber.