Virtual Metrology for ESC Temperature Estimation
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Solution Overview
Problem
Substrate processing systems face challenges in accurately controlling and measuring temperature uniformity on substrate supports, such as electrostatic chucks, due to variations in manufacturing processes and system components, leading to non-uniform substrate temperatures.
Innovation Solution
A temperature controller system that uses a model correlating thermal control elements' resistances and temperature responses to estimate and control the substrate support's temperature, incorporating macro and micro thermal control elements to compensate for temperature non-uniformities, and virtual metrology to estimate surface temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional temperature measurement methods are used, then the system structure is simple, but the measurement precision and temperature uniformity control are insufficient
Solution Approach 1:
The patent replaces physical temperature sensors with a virtual metrology system that uses electrical resistance measurements of thermal control elements to infer temperature. The temperature estimation module substitutes direct mechanical/physical measurement with computational estimation based on electrical properties, achieving higher precision without adding sensor complexity
Solution Approach 2:
The patent introduces thermal control elements as intermediary components that serve dual purposes: they control temperature and simultaneously provide resistance measurements that indicate temperature. This intermediary approach allows temperature inference without direct sensing, resolving the contradiction between precision and complexity
2Manufacturing precision
If multiple thermal control elements are used to improve temperature uniformity, then the temperature control precision is improved, but the device complexity increases
Solution Approach 1:
The patent divides the substrate support into multiple zones with separate thermal control elements (macro-TCEs and micro-TCEs), allowing independent temperature control of different regions. This segmentation enables precise temperature uniformity control across the substrate surface while managing complexity through modular zoned control
Solution Approach 2:
The patent implements different types of thermal control elements at different locations: macro-TCEs for overall temperature control and micro-TCEs for local temperature adjustments. This local quality approach optimizes temperature uniformity by providing appropriate control resolution at each spatial scale without uniformly complicating the entire system
3Manufacturing precision
If real-time temperature control is implemented, then the temperature uniformity is improved, but the processing time and system complexity increase
Solution Approach 1:
The patent implements a feedback control loop where the temperature estimation module continuously monitors temperature conditions and the controller adjusts thermal control element power in real-time. This feedback mechanism maintains temperature uniformity dynamically during substrate processing, compensating for temperature drift without requiring excessive processing time
Solution Approach 2:
The patent performs preliminary temperature control by adjusting thermal control elements before and during substrate processing to prevent temperature non-uniformities from developing. This proactive approach maintains temperature uniformity without requiring corrective actions that would extend processing time
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 approach allows for more accurate temperature control and estimation of substrate supports, reducing temperature non-uniformities and improving substrate processing outcomes by using a combination of macro and micro thermal control elements and virtual metrology.
Implementation Method 1
A temperature estimation module calculates resistances of the first TCEs, determines, based on the calculated resistances, the temperatures of the first TCEs
Data Source
AI summary
A temperature controller for a substrate support in a substrate processing system includes memory that stores a first model correlating temperatures of a plurality of first thermal control elements (TCEs) arranged in the substrate support and first temperature responses of the substrate support. The first temperature responses correspond to locations on a surface of the substrate support. A temperature estimation module calculates resistances of the first TCEs, determines, based on the calculated resistances, the temperatures of the first TCEs, and estimates, using the stored first model and the determined temperatures of the first TCEs, an actual temperature response of the substrate support. The temperature controller is configured to control the first TCEs based on the actual temperature response of the substrate support.