Multi-Zone Substrate Support Heating With Single-Sensor Temperature Control
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Solution Overview
Problem
Substrate processing systems face challenges in maintaining thermal uniformity across multiple zones without the need for direct temperature measurement in each zone or individual calibration, particularly under varying heat loads during processes like chemical vapor deposition and plasma etching.
Innovation Solution
A dynamic temperature control system that uses a single temperature sensor in one zone to calculate and adjust the resistances of multiple resistive heaters based on resistance ratios, eliminating the need for thermocouples in other zones and prior calibration, by monitoring voltages and currents supplied to maintain uniform temperature across all zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If direct temperature measurement is implemented in each zone, then temperature uniformity can be maintained, but device complexity and manufacturing cost increase due to requiring multiple thermocouples and calibration procedures
Solution Approach 1:
The patent extracts the temperature measurement function from multiple zones and consolidates it into a single reference zone. By measuring temperature in only one zone and using resistance ratios to infer temperatures in other zones, the system eliminates the need for multiple thermocouples and complex calibration procedures while maintaining temperature uniformity control
Solution Approach 2:
The patent introduces resistance ratios as an intermediary parameter to indirectly determine temperatures in zones without direct measurement. By monitoring the resistance ratios between heater zones and using the measured temperature from the reference zone, the system can calculate and control temperatures in all zones without requiring direct measurement in each zone
2Manufacturing precision
If individual calibration is performed for each heater zone, then accurate temperature control is achieved, but manufacturing time and complexity increase
Solution Approach 1:
The patent makes the single reference zone temperature measurement and resistance ratio calculations serve all heater zones simultaneously. The resistance ratios act as universal scaling factors that allow one calibration reference to control multiple zones, eliminating the need for individual calibration of each zone while maintaining accurate temperature control
Solution Approach 2:
The system uses the inherent electrical resistance properties of the heater zones themselves as the measurement mechanism. By monitoring voltage and current to calculate resistance ratios, the system performs self-diagnosis and self-regulation of temperature distribution without requiring external calibration procedures for each zone
3Measurement precision
If multiple temperature sensors are deployed in different zones, then temperature variations can be detected, but the system becomes more complex and costly
Solution Approach 1:
The patent extracts the temperature sensing function from multiple zones and concentrates it in a single reference zone. By using electrical resistance monitoring and ratio calculations, the system infers temperature information in all zones from a single measurement point, thereby reducing the sensor system from multiple thermocouples to a single temperature sensor plus electrical measurement circuitry
4Temperature
If resistance heaters are controlled independently in each zone, then temperature uniformity can be maintained, but the control system complexity increases
Solution Approach 1:
The patent implements a feedback control system where the measured temperature from the reference zone and the calculated resistance ratios are used to dynamically adjust the power supplied to each heater zone. This feedback mechanism enables automatic compensation for temperature variations across zones without requiring complex independent control of each zone, as the resistance ratios provide continuous information about relative temperature states
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 ensures temperature uniformity across all zones without the requirement for thermocouples or individual calibration, effectively managing temperature variations and preventing substrate support failure, thereby enhancing process control and reducing defects.
Implementation Method 1
the temperature of the substrate may be controlled by resistance heaters that are arranged in the substrate support
Implementation Method 2
A temperature sensor is located in one of the N zones
Implementation Method 3
adjust power to N−1 of the N resistive heaters during operation of the substrate processing system in response to the temperature measured in the one of the N zones
Data Source
AI summary
A temperature-controlled substrate support for a substrate processing system includes a substrate support located in the processing chamber. The substrate support includes N zones and N resistive heaters, respectively, where N is an integer greater than one. A temperature sensor is located in one of the N zones. A controller is configured to calculate N resistances of the N resistive heaters during operation and to adjust power to N−1 of the N resistive heaters during operation of the substrate processing system in response to the temperature measured in the one of the N zones by the temperature sensor, the N resistances of the N resistive heaters, and N−1 resistance ratios.