Electrostatic Chuck Heater Trace Temperature Sensing Without Embedded Sensors
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Solution Overview
Problem
Existing semiconductor fabrication processes face challenges in accurately measuring the temperature of electrostatic chucks during plasma processing without the use of temperature sensors, which affects the control of substrate temperature and process outcomes.
Innovation Solution
An electrostatic chuck system that integrates a heater trace with a voltage and current sensor to approximate temperature using a correlation function based on the resistance of the heater trace, eliminating the need for embedded temperature sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temperature sensors are embedded in the heater zone of the electrostatic chuck, then temperature measurement accuracy is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The heater trace is designed to serve dual functions: heating the substrate and sensing temperature through resistance measurement. By making the heater trace multi-functional, the patent eliminates the need for separate temperature sensors, thereby reducing device complexity while maintaining temperature measurement capability
Solution Approach 2:
The heater trace measures its own temperature through its electrical resistance, which changes with temperature. This self-sensing capability allows the heater element to provide its own temperature feedback without requiring external sensors, simplifying the overall system
2Measurement precision
If temperature sensors are embedded in the heater zone of the electrostatic chuck, then temperature measurement accuracy is improved, but manufacturing cost increases
Solution Approach 1:
The heater trace is designed to serve dual functions: heating the substrate and sensing temperature through resistance measurement. By making the heater trace multi-functional, the patent eliminates the need for separate temperature sensors, thereby reducing device complexity while maintaining temperature measurement capability
Solution Approach 2:
The patent uses the existing heater trace, which is already a simple resistive element, for temperature sensing purposes. This approach avoids the need for expensive temperature sensors and simplifies manufacturing by utilizing an existing component for multiple functions
3Measurement precision
If temperature sensors are embedded in the heater zone of the electrostatic chuck, then temperature measurement accuracy is improved, but system thickness increases
Solution Approach 1:
The heater trace is designed to serve dual functions: heating the substrate and sensing temperature through resistance measurement. By making the heater trace multi-functional, the patent eliminates the need for separate temperature sensors, thereby reducing device complexity while maintaining temperature measurement capability
Solution Approach 2:
The patent extracts the temperature sensing function from separate sensor components and integrates it into the existing heater trace through electrical resistance measurement. This eliminates the need for physical temperature sensors in the heater zone, thereby reducing system thickness
4Device complexity
If resistance measurement of heater trace is used to approximate temperature, then device complexity is reduced, but measurement precision may be affected
Solution Approach 1:
The patent uses the electrical resistance parameter of the heater trace, which changes with temperature, as a proxy for direct temperature measurement. By monitoring resistance changes and correlating them to temperature through calibration, the system achieves accurate temperature approximation without complex sensor infrastructure
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
Provides accurate temperature measurement and control of electrostatic chuck heater zones, enabling closed-loop heating control, reducing system thickness, and lowering costs while improving RF uniformity and process control.
Implementation Method 1
The correlation function uses a temperature coefficient of resistance of the heater trace
Implementation Method 2
the voltage sensor configured to sense a voltage difference across the heater trace
Implementation Method 3
the current sensor coupled to the heater trace and configured to sense a current in the heater trace
Implementation Method 4
a heater trace in a heater zone of the ESC, wherein the heater trace is configured for sensing temperature through a determined resistance of the heater trace
Data Source
AI summary
A controller including a voltage sensor coupled to a heater trace integrated in an electrostatic chuck, the voltage sensor configured to sense a voltage difference across the heater trace, wherein the heater trace is associated with a heater zone. The controller including a current sensor coupled to the heater trace and configured to sense a current in the heater trace. The controller including a resistance identifier configured to identify a resistance of the heater trace based on the voltage difference and the current that is sensed. The controller including a temperature correlator configured to approximate a temperature of the heater zone based on the resistance and a correlation function of the heater trace. The correlation function uses a temperature coefficient of resistance of the heater trace.