Electrostatic Chuck Thermocouple Temperature Measurement
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Solution Overview
Problem
Conventional electrostatic chucks with embedded thermocouples face challenges in accurately measuring temperature due to small temperature distribution, leading to difficulties in generating a large thermal electromotive force.
Innovation Solution
An electrostatic chuck with a thermocouple comprising a first metal part and a second metal part, along with corresponding wire parts, are integrated inside the base, allowing for a larger temperature distribution and improved thermal electromotive force generation, enabling accurate temperature measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a thermocouple is embedded only within the electrostatic chuck having a small temperature distribution, then the structure is simple, but it is difficult to generate a large thermal electromotive force and accurately measure the temperature
Solution Approach 1:
The patent extends the thermocouple structure from a single-point measurement within the electrostatic chuck to a distributed structure that includes both the electrostatic chuck and the base plate. By adding the spatial dimension of the base plate to the measurement system, the thermocouple can detect temperature differences across multiple locations, generating a larger thermal electromotive force while maintaining measurement accuracy.
Solution Approach 2:
The patent introduces the base plate as an intermediary element that facilitates temperature difference generation. The base plate acts as a thermal mediator between the heater element and the electrostatic chuck, creating a temperature gradient that enhances the thermal electromotive force generated by the thermocouple without complicating the core measurement function.
2Measurement precision
If the thermocouple is provided only within the electrostatic chuck, then the installation is simple, but the temperature difference is insufficient for accurate measurement
Solution Approach 1:
The patent merges the thermocouple installation into an integrated structure that combines both the electrostatic chuck and the base plate as a single functional unit. This unified approach allows the thermocouple to span across both components, capturing temperature differences while maintaining a streamlined manufacturing process that does not require separate installation steps for each component.
3Measurement precision
If a larger temperature distribution is utilized, then a larger thermal electromotive force is generated, but the device structure becomes more complex
Solution Approach 1:
The patent makes the base plate serve multiple functions: it provides structural support for the electrostatic chuck, acts as a thermal conductor to create temperature gradients, and serves as part of the thermocouple measurement system. This multi-functionality allows the generation of larger thermal electromotive force without adding dedicated components, thereby avoiding increased device complexity.
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 solution allows for precise temperature measurement and improved noise immunity by generating a larger thermal electromotive force, enhancing the accuracy of temperature detection within the electrostatic chuck.
Implementation Method 1
an appropriate temperature difference is not easily generated at the thermocouple, and it is difficult to obtain a large thermal electromotive force
Implementation Method 2
a substrate fixing apparatus, that retains the wafer within the vacuum processing chamber by electrostatic retention using an electrostatic chuck
Data Source
AI summary
An electrostatic chuck includes a base having a support surface configured to retain a retaining target by electrostatic retention, and a thermocouple configured to detect a temperature of the base. The thermocouple includes first and second metal parts provided inside the base and having ends connected to each other to form a measuring junction, a first wire part having one end connected to the other end of the first metal part inside the base, and another end extending outside the base, and a second wire part having one end connected to the other end of the second metal part inside the base, and another end extending outside the base. The first metal part and the first wire part are formed from a first material, and the second metal part and the second wire part are formed from a second material different from the first material.