Polarization-Based Stray Light Reduction in Thermal Processing
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Solution Overview
Problem
Current temperature measurement techniques during semiconductor processing are affected by noise from radiant energy sources, leading to inaccurate readings and increased system complexity.
Innovation Solution
The apparatus and method involve marking radiant energy from the source using polarization, reflection, or absorption to distinguish and separate energy from the substrate, allowing for precise temperature measurement by a sensor assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If covers and shields are used to prevent background noises from entering the sensor, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts and removes the harmful radiant energy from the energy source before it reaches the sensor by using a polarizer to block polarized light. This eliminates the need for complex covers and shields, reducing device complexity while maintaining measurement precision.
Solution Approach 2:
A polarizer is introduced as an intermediary component between the energy source and the sensor. This polarizer selectively blocks polarized radiant energy from the source while allowing non-polarized or differently polarized radiation from the substrate to pass through, simplifying the overall system design.
2Measurement precision
If covers and shields are used to block radiation from the energy source, then measurement precision is improved, but the lower range of sensors is limited
Solution Approach 1:
The harmful polarized radiation is extracted and removed using a polarizer, allowing the sensor to detect a broader range of temperatures without being overwhelmed by background noise. This extends the lower range of the sensor while maintaining measurement precision.
Solution Approach 2:
The patent changes the polarization state of the radiant energy using a polarizer, transforming the harmful polarized light into a form that can be selectively blocked. This parameter change enables the sensor to operate across a wider temperature range with improved accuracy.
3Device complexity
If radiant energy from the energy source is allowed to reach the sensor, then system simplicity is maintained, but measurement precision deteriorates due to noise
Solution Approach 1:
A polarizer is positioned between the energy source and the sensor to act as a selective mediator. It blocks polarized radiant energy from the source while allowing radiation from the substrate to reach the sensor, maintaining system simplicity while improving measurement precision.
Solution Approach 2:
The polarizer changes the polarization parameter of the radiant energy, selectively filtering out polarized light from the energy source. This simple parameter-based filtering maintains system simplicity while dramatically improving temperature measurement accuracy by eliminating noise.
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 reduces noise interference, enhancing the accuracy of temperature measurement and simplifying the system by isolating the substrate's radiant energy from the energy source's radiation.
Implementation Method 1
a source polarizer configured to polarize the radiant energy directed from the energy source towards the processing volume along a first direction
Implementation Method 2
a sensor polarizer configured to polarize radiant received by the sensor assembly along a second direction substantially perpendicular to the first direction
Implementation Method 3
an energy source disposed outside the chamber enclosure, wherein the energy source is configured to direct radiant energy towards the processing volume through the energy window
Implementation Method 4
a sensor assembly configured to measure temperature of the substrate being processed by sensing radiation from the substrate within a selected spectrum
Data Source
AI summary
Embodiments of the present invention provide apparatus and method for reducing noises in temperature measurement during thermal processing. One embodiment of the present invention provides a chamber for processing a substrate comprising a chamber enclosure defining a processing volume, an energy source configured to direct radiant energy toward the processing volume, a spectral device configured to treat the radiant energy directed from the energy source towards the processing volume, a substrate support disposed in the processing volume and configured to support the substrate during processing, and a sensor assembly configured to measure temperature of the substrate being processed by sensing radiation from the substrate within a selected spectrum.