Rotating Substrate Support with Integrated Heater for Uniform Processing
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Solution Overview
Problem
In vertical batch furnaces, achieving uniform temperature control for lower substrates is challenging due to their proximity to the cold lower door zone, and existing solutions, such as magnetically coupled wafer rotation, require a bearing in the high-temperature processing environment, which is prone to soiling and reduced lifespan.
Innovation Solution
A semiconductor substrate processing apparatus with a rotatable substrate support and integrated heater, where the support is rotated relative to the heater to average out non-uniformities in the heat profile, eliminating the need for a bearing within the reaction space by using a bearing outside the furnace atmosphere.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a bearing mechanism is placed inside the furnace to enable wafer boat rotation, then the wafer boat can be rotated to average out heating non-uniformities, but the bearing will be exposed to high-temperature processing environment causing soiling and reduced lifespan
Solution Approach 1:
The bearing mechanism is extracted from the high-temperature furnace environment and placed in the cooler external environment. The drive shaft extends through the furnace wall, allowing the wafer boat to be rotated by an external motor without exposing the bearing to harmful high-temperature processing conditions that cause soiling and reduced lifespan.
Solution Approach 2:
A drive shaft acts as an intermediary component, transmitting rotational force from the external motor through the furnace wall to rotate the wafer boat. This intermediary allows the bearing to remain outside the furnace while still enabling the required rotation function inside the processing chamber.
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 enhances within-substrate temperature uniformity by rotating the substrate support relative to the heater, reducing the impact of heater non-uniformities and extending the apparatus' lifespan by avoiding high-temperature exposure for critical components.
Implementation Method 1
a heater comprising a heat dissipating portion that is disposed within the substrate support and that extends underneath and substantially parallel to the support surface
Implementation Method 2
The substrate support is rotatably mounted around an rotation axis that extends through said support surface, such that the support surface is rotatable relative to the heat dissipating portion of the heater
Data Source
AI summary
A semiconductor substrate processing apparatus (1), comprising a substrate support assembly (30), including a substrate support (32) defining an outer support surface (34) for supporting a substrate or substrate carrier (24) thereon, and a heater (50) comprising a heat dissipating portion (54) that is disposed within the substrate support (32) and that extends underneath and substantially parallel to the support surface (34), said substrate support (32) being rotatably mounted around a rotation axis (L) that extends through said support surface (34), such that the support surface (34) is rotatable relative to the heat dissipating portion (54) of the heater (50).