Heated Substrate Support with Shaft Heater for Temperature Uniformity
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Solution Overview
Problem
Conventional heated substrate supports with embedded heaters exhibit temperature non-uniformity due to heat being drawn away by the support shaft, leading to non-uniform process results on semiconductor substrates.
Innovation Solution
A substrate support system with a plate heater and temperature sensor, coupled to a controller, and a shaft heater and temperature sensor, also coupled to a controller, to maintain uniform temperature across the substrate, minimizing heat loss and thermal stresses at the interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a support shaft is used to support the substrate support, then mechanical support and stability are provided, but heat is drawn away from the substrate support causing temperature non-uniformity
Solution Approach 1:
A shaft heater is introduced as an intermediary element between the support shaft and the substrate support plate. The shaft heater compensates for the heat drawn away by the support shaft, thereby maintaining temperature uniformity across the substrate support while preserving the mechanical support function of the shaft.
Solution Approach 2:
The heating system is divided into two distinct zones: a plate heater for the substrate support plate and a shaft heater for the support shaft. This local differentiation allows each heater to address the specific thermal needs of its component, ensuring overall temperature uniformity despite the heat-sinking effect of the shaft.
2Loss of energy
If the support shaft draws heat away from the substrate support, then heat loss is reduced in the shaft, but temperature non-uniformity and thermal stresses increase at the interface
Solution Approach 1:
The shaft heater provides preliminary heating to the support shaft before and during substrate processing. This preliminary anti-action counteracts the heat that would otherwise be drawn away from the substrate support plate, preventing temperature gradients and thermal stresses at the interface between the shaft and plate.
Solution Approach 2:
Temperature sensors are placed at the interface between the support shaft and substrate support plate to monitor temperature distribution. This feedback information is used to dynamically adjust the shaft heater and plate heater power, ensuring uniform temperature and minimizing thermal stresses while maintaining energy efficiency.
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 closed-loop control system ensures improved temperature uniformity and minimizes thermal stresses, resulting in more consistent substrate processing outcomes, such as in chemical vapor deposition and atomic layer deposition processes.
Implementation Method 1
a plate heater disposed in the plate... a shaft heater... wherein the plate heater and the plate temperature sensor are coupled to a controller; a shaft temperature sensor disposed at the first end wherein the shaft temperature sensor and the shaft heater are coupled to a controller
Implementation Method 2
a plate temperature sensor disposed in the plate... a shaft temperature sensor disposed at the first end
Data Source
AI summary
Methods and apparatus of substrate supports having temperature profile control are provided herein. In some embodiments, a substrate support includes: a plate having a substrate receiving surface and an opposite bottom surface; and a shaft having a first end comprising a shaft heater and a second end, wherein the first end is coupled to the bottom surface. Methods of making a substrate support having temperature profile control are also provided.