Elastic Wave Device for Wireless Wafer Temperature Measurement
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Solution Overview
Problem
Existing thermal processing apparatuses for semiconductor wafers face challenges in achieving precise temperature control due to deviations in temperature measurements caused by non-contact thermocouples, which can lead to metal contamination and inefficiencies in temperature regulation, especially during high-temperature processes.
Innovation Solution
A thermal processing apparatus utilizing a langasite or LTGA substrate-based elastic wave device that generates electric waves based on temperature, with conductive members acting as transmitter and receiver antennas, allowing for wireless and real-time temperature measurement and control without additional antennas or metal contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thermocouple is disposed inside or outside the processing vessel to measure wafer temperature, then temperature control can be implemented, but the measurement precision deteriorates due to deviation from actual wafer temperature and potential metal contamination
Solution Approach 1:
The patent replaces the mechanical contact-based thermocouple measurement system with a non-contact electromagnetic wave-based temperature measurement system. The elastic wave device on the wafer surface detects temperature through electromagnetic wave frequency changes, eliminating the need for physical thermocouple contact and thereby preventing metal contamination while improving measurement accuracy.
Solution Approach 2:
The patent introduces an elastic wave device as an intermediary element that is placed on the wafer surface. This device acts as a mediator between the wafer temperature and the measurement system, converting temperature information into electromagnetic wave frequency changes that can be detected without direct thermocouple contact with the wafer.
2Measurement precision
If additional separate antennas are installed for wireless temperature measurement, then measurement precision improves, but device complexity increases
Solution Approach 1:
The patent makes the processing vessel wall serve multiple functions: it acts as both the containment structure for the processing chamber and as the antenna for transmitting and receiving electromagnetic waves. This eliminates the need for separate antenna components while maintaining wireless temperature measurement capability.
Solution Approach 2:
The patent merges the function of the processing vessel wall with the antenna function. The conductive material of the vessel wall is utilized to both contain the processing environment and to transmit/receive electromagnetic waves for temperature measurement, combining structural and measurement functions into a single component.
3Device complexity
If conventional thermocouple methods are used for temperature measurement, then device complexity remains low, but reliability deteriorates due to metal contamination and fluctuating correlations
Solution Approach 1:
The patent replaces the mechanical contact-based thermocouple system with a non-contact electromagnetic measurement system using an elastic wave device. This substitution eliminates metal contamination issues and the fluctuating correlation problems associated with thermocouples while maintaining relatively simple device architecture.
Solution Approach 2:
The elastic wave device on the wafer surface serves as a self-contained temperature sensor that directly measures its own temperature through electromagnetic wave frequency changes. The system uses the wafer's own material properties (elastic wave characteristics) for measurement, eliminating the need for external reference measurements and correlation calculations.
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
Enables highly precise temperature control and accurate measurement of wafer temperatures, even during temperature changes and when films adhere to the processing vessel, ensuring efficient film deposition processes without metal contamination.
Implementation Method 1
a langasite or LTGA substrate-based elastic wave device that generates electric waves based on temperature
Implementation Method 2
with conductive members acting as transmitter and receiver antennas, allowing for wireless and real-time temperature measurement and control
Implementation Method 3
the wafers are heated by a heating unit disposed on an outer circumference of the processing vessel so that temperatures of the wafers are raised
Data Source
AI summary
A thermal processing apparatus comprising a processing vessel containing, in addition to a plurality of objects subject to heat treatment, an acoustic wave device for temperature measurement. A holding unit holds the plurality of objects to be processed and an object for temperature measurement utilizing an acoustic wave device. A heating unit heats the objects to be processed and the object for temperature measurement. A first conductive member functions as an antenna for transmitting an electromagnetic wave toward the acoustic wave device in the processing vessel; a second conductive member functions as a receiver antenna for receiving an electromagnetic wave dependent on a temperature of the acoustic wave device which is emitted from the acoustic wave device. A temperature analysis part obtains a temperature of the object based on the electromagnetic wave received by the receiver antenna, and a temperature control part controls the heating unit. The first and second conductive members are each part of the thermal processing parts in the processing vessel.