Susceptor Heater Segmentation for Temperature Uniformity
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Solution Overview
Problem
Existing substrate heating systems face challenges in achieving uniform temperature across the susceptor and substrate, particularly in the central region, due to limitations in coil heaters and heat sink effects from the riser shaft, which hinder high-quality semiconductor component production.
Innovation Solution
The system employs a substrate support assembly with a susceptor and riser shaft, featuring a planar heater embedded within the susceptor and an additional heater extending downwardly from the riser shaft, allowing independent control of heat distribution to maintain tight temperature tolerances across the substrate support surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a coil heater is embedded within the susceptor, then the susceptor and substrate can be heated, but the minimum bending radius of the coil heater limits the ability to heat the central area uniformly
Solution Approach 1:
The heating system is divided into multiple independent heating zones: a first coil heater embedded in the susceptor for outer region heating, and a second heater (resistance heater or induction heater) positioned to heat the central region. This segmentation allows each heater to be optimized for its specific zone, overcoming the bending radius limitation of coil heaters in the central area.
Solution Approach 2:
Different heating methods are applied to different regions of the susceptor: the first coil heater provides heating for the outer regions where curved geometry is acceptable, while the second heater (with different geometric constraints) provides heating for the central region where uniform temperature is critical. This local differentiation resolves the uniformity issue without requiring complex coil configurations throughout.
2Reliability
If the riser shaft is used to support the susceptor, then the susceptor can be securely positioned, but the riser shaft acts as a heat sink that draws heat from the central region
Solution Approach 1:
The second heater is positioned to pre-heating the central region of the susceptor and the riser shaft interface before the main heating cycle begins. This preliminary heating counteracts the heat sink effect of the riser shaft during subsequent processing, maintaining central region temperature uniformity while preserving the mechanical support function of the riser shaft.
Solution Approach 2:
The second heater acts as an intermediary heating element that specifically targets the heat sink region created by the riser shaft. By introducing this intermediate heating source between the riser shaft and the susceptor central region, the system compensates for heat draw without modifying the riser shaft's structural support function.
3Manufacturing precision
If tighter temperature control is implemented, then temperature uniformity improves, but the heating system complexity increases
Solution Approach 1:
The heating system is segmented into multiple independently controllable heating zones with separate heaters and control circuits. This allows precise temperature control in each zone (susceptor outer region, susceptor central region, riser shaft) without requiring complex control logic, as each zone can be regulated independently to achieve overall temperature uniformity.
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 configuration enables precise temperature control, reducing temperature variation to less than 0.5°C across the susceptor and substrate, enhancing the quality of semiconductor processing and reducing reject rates.
Implementation Method 1
A resistance heating coil or other heating mechanism is typically enclosed within the susceptor to provide conductive heat to increase the temperature of the susceptor and the semi-conductor substrate when seated thereon
Implementation Method 2
a second heater which extends downwardly adjacent the first end of the riser shaft
Data Source
AI summary
The present disclosure relates to a substrate support and a heating assembly comprising heaters for controlling the temperature uniformity of a susceptor of the assembly and a substrate, which may be used for thin film deposition on a substrate such as semi-conductor wafer, and a method of using the same is provided for improved temperature uniformity of a susceptor and a substrate heated by the heating assembly.