Quartz Susceptor Structure for Accurate Pyrometer Temperature Sensing
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Solution Overview
Problem
Conventional epitaxial processing chambers face challenges in accurately controlling substrate temperatures during annealing, which affects the uniformity of material deposition and production yields, particularly for next-generation semiconductor devices.
Innovation Solution
A semiconductor processing chamber with a susceptor assembly that incorporates an IR blocking material encased in an IR transparent material, allowing for non-contact measurement of substrate temperature using pyrometers, ensuring fixed emissivity and accurate temperature determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional susceptor materials are used in epitaxial processing chambers, then the substrate can be heated, but accurate non-contact temperature measurement cannot be achieved due to varying emissivity
Solution Approach 1:
The patent applies local quality by creating a specific region on the susceptor surface with different optical properties. An IR-transparent window is formed in the susceptor body, allowing infrared radiation to pass through from the substrate to the pyrometer, while the rest of the susceptor maintains its thermal blocking function. This localized modification enables accurate temperature measurement without compromising the overall susceptor performance
Solution Approach 2:
The patent introduces an intermediary solution by using an IR-transparent material (such as quartz or sapphire) as a window in the susceptor. This intermediary allows infrared radiation to pass through while maintaining the structural integrity and thermal management functions of the susceptor, thereby enabling accurate non-contact temperature measurement
2Measurement precision
If the susceptor body is made fully IR transparent for pyrometer measurement, then temperature can be measured, but IR heating efficiency is reduced
Solution Approach 1:
The susceptor is designed with a localized IR-transparent window rather than being fully transparent. This allows infrared radiation to pass through only at the specific measurement location, while the rest of the susceptor body remains opaque to maintain efficient IR heating of the substrate. The local quality principle resolves the contradiction by spatially separating the measurement function from the heating function
3Manufacturing precision
If conventional susceptor designs are used, then simple structure is maintained, but temperature control precision cannot meet next generation device requirements
Solution Approach 1:
The susceptor structure is modified locally by incorporating an IR-transparent window in a specific region, rather than redesigning the entire susceptor. This minimal structural change enables precise temperature measurement and control while maintaining the overall simplicity and manufacturability of the susceptor design
Solution Approach 2:
The susceptor is constructed using composite materials, combining an IR-opaque material (such as graphite or ceramic) with an IR-transparent material (such as quartz or sapphire) for the window portion. This composite structure enables both the thermal management functions and the temperature measurement capability, achieving high manufacturing precision without excessive complexity
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 solution enables precise temperature control and measurement, enhancing process uniformity, yield, throughput, and tool-to-tool process matching in epitaxial and other semiconductor processing chambers.
Implementation Method 1
The IR blocking material is optically opaque at IR wavelengths
Implementation Method 2
the lower portion is optically transparent at IR wavelengths
Data Source
AI summary
The present disclosure generally relates to a substrate support for processing of semiconductor substrates. In one example, the substrate support has a body. The body has a top surface configured to support a substrate thereon. The body has a bottom surface opposite the top surface. The body has an upper portion disposed at the top surface and a lower portion disposed at the bottom surface. An IR blocking material is encased by the upper portion and the lower portion, wherein the IR blocking material is an optically opaque at IR wavelengths and the lower portion is optically transparent at IR wavelengths.