Radiation Heating Substrate Holder for Uniform Thermal Processing
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Solution Overview
Problem
Existing substrate heat-treating apparatuses face issues with non-uniform heating due to uneven contact between the substrate and holder, leading to surface roughness and prolonged cooling times, and are often bulky due to inefficient cooling methods.
Innovation Solution
A substrate heat-treating apparatus with a carbon or carbon-covered substrate holder and a non-contact heating unit using radiation heat, where the substrate holder and heating unit are vertically movable to ensure uniform heating and cooling, utilizing radiation plates and reflection plates to enhance heat dissipation and absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If heating is performed by heat conduction through the substrate holder, then the substrate can be heated, but nonuniformity occurs in heating when the substrate and substrate holder are not in contact evenly
Solution Approach 1:
The patent replaces the mechanical heat conduction system (substrate holder contacting substrate) with a radiation-based heating system. The heating unit irradiates the substrate with radiation heat directly, eliminating the need for physical contact between the substrate and holder, thus ensuring uniform heating regardless of substrate flatness or contact uniformity.
Solution Approach 2:
The patent introduces radiation heat as an intermediary between the heating unit and the substrate. Instead of direct thermal contact, heat is transferred through electromagnetic radiation, which can uniformly penetrate and heat the substrate surface without requiring physical contact, thereby solving the contact uniformity problem.
2Loss of time
If the substrate is cooled by the periphery of the substrate holder, then cooling can be achieved, but the temperature of the entire substrate cannot be uniformly lowered and it takes time to cool the substrate through its center
Solution Approach 1:
The patent replaces the mechanical cooling system (substrate holder conducting heat away) with a radiation-based cooling system. The heating unit can switch to cooling mode by irradiating the substrate with cooling radiation, enabling rapid and uniform cooling of the entire substrate surface simultaneously, rather than slow conductive cooling from the periphery.
Solution Approach 2:
The patent inverts the conventional cooling approach by using the same heating unit to perform cooling through radiation. Instead of relying on passive heat conduction to the holder, the system actively radiates cooling energy onto the substrate surface, reversing the heat flow direction and achieving rapid uniform cooling across the entire substrate.
3Loss of time
If a cooling portion is provided to cool the substrate, then cooling can be achieved, but a large space must be reserved for the cooling portion which makes the apparatus bulky
Solution Approach 1:
The patent makes the heating unit multi-functional by enabling it to perform both heating and cooling operations. The same radiation source can switch between emitting heating radiation and cooling radiation, eliminating the need for a separate cooling portion and thereby reducing the apparatus size while maintaining full cooling capability.
Solution Approach 2:
The patent merges the heating and cooling functions into a single integrated unit. Instead of having separate heating and cooling components that would increase apparatus volume, the system combines both functions in one radiation-based unit, achieving space-efficient design without sacrificing cooling performance.
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
The apparatus achieves uniform and rapid heating and cooling of substrates, regardless of warpage, while reducing the apparatus size by optimizing heat transfer and absorption, thereby improving surface uniformity and processing efficiency.
Implementation Method 1
heats the substrate placed on the substrate stage in noncontact therewith with radiation heat from the heat dissipation surface
Implementation Method 2
a radiation plate which is arranged under the substrate stage at a gap therefrom, catches heat emitted from a lower surface of the substrate stage, and radiates the caught heat toward the substrate stage
Implementation Method 3
a reflection plate which is arranged under the radiation plate at a gap therefrom and reflects heat emitted from the radiation plate
Data Source
AI summary
An apparatus for heat treating a substrate includes a substrate holder unit including a substrate stage on which a substrate is to be placed and which is made of one of a carbon and a carbon covered material, and a heating unit which is provided above the substrate stage and includes a heat dissipation surface opposing the substrate stage, and heats the substrate placed on the substrate stage in noncontact therewith radiation heat from the heat dissipation surface. In addition, a chamber contains the substrate holder unit and the heating unit, and an elevating device vertically moves at least one of the substrate holder unit and the heating unit in the chamber to bring the substrate stage and the heat dissipation surface of the heating unit close to each other or apart from each other. The substrate holder unit includes a radiation plate which is arranged under the substrate stage at a gap therefrom, and a reflection plate which is arranged under the radiation plate at a gap therefrom.