Non-Contact Infrared Temperature Control for High-Temp Heating Apparatus
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Solution Overview
Problem
Conventional heating process apparatuses face challenges in achieving precise temperature control, especially at high temperatures above 1850 degrees, due to the limitations of tungsten-rhenium thermo couples, which do not allow for direct contact measurement and are prone to deterioration, leading to inaccurate and unreliable temperature control across varying substrate sizes.
Innovation Solution
A heating process apparatus utilizing a temperature measuring system that includes a transmissive window for non-contact infrared measurement, using a dual-wavelength radiation thermometer to calculate temperatures based on the intensity ratio of infrared radiation, enabling accurate temperature control up to 2400 degrees without substrate displacement and maintaining consistent heat capacity across different substrate sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a tungsten-rhenium thermo couple is inserted into a groove in the side surface of the heat-processed object support member to measure temperature, then temperature control can be implemented, but the measurement precision deteriorates due to steep temperature gradient at the side surface location
Solution Approach 1:
The patent replaces the mechanical contact-based tungsten-rhenium thermo couple with a non-contact infrared temperature measuring device. This substitution eliminates the need to insert the sensor into the heat-processed object support member, thereby avoiding measurement errors caused by steep temperature gradients at the side surface while maintaining reliable temperature control capability
Solution Approach 2:
The patent introduces an infrared transmissive window as an intermediary element that allows infrared radiation from the heat-processed object support member to reach the temperature measuring device outside the chamber. This intermediary enables accurate temperature measurement of the top surface without direct contact, resolving the contradiction between measurement accessibility and measurement precision
2Reliability
If a tungsten-rhenium thermo couple is used for temperature measurement, then temperature control can be achieved, but the device reliability deteriorates due to deterioration and breakage at high temperatures above 1850 degrees
Solution Approach 1:
The patent replaces the fragile tungsten-rhenium thermo couple with a non-contact infrared temperature measuring device. This substitution eliminates the physical contact and high-temperature exposure issues that cause deterioration and breakage, thereby extending the service life while maintaining reliable temperature control at temperatures above 1850 degrees
Solution Approach 2:
The patent uses infrared radiation as a copy or proxy for direct temperature measurement. Instead of placing a physical sensor that would deteriorate at high temperatures, the system measures the infrared radiation emitted by the heat-processed object support member, providing indirect but reliable temperature information without exposing any sensor to the harsh high-temperature environment
3Adaptability or versatility
If conventional contact-based temperature measurement is used, then temperature control can be implemented, but the adaptability deteriorates because the temperature of the heat-processed object support member and substrate cannot be correlated
Solution Approach 1:
The patent replaces contact-based temperature measurement with non-contact infrared measurement, enabling direct measurement of the heat-processed object support member temperature at its top surface. This approach allows for accurate temperature correlation between the heat-processed object support member and substrate, improving adaptability while maintaining measurement precision
Solution Approach 2:
The non-contact infrared temperature measuring device provides universal temperature measurement capability for both the heat-processed object support member and the substrate. By measuring infrared radiation from both components, the system establishes reliable temperature correlation between them, enhancing the overall adaptability of the heating process apparatus
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 solution allows for reliable, non-contact direct temperature measurement and control, ensuring consistent temperature control across a wide temperature range, preventing substrate displacement and ensuring reproducible heating processes by eliminating variations in emission current values.
Implementation Method 1
a transmissive window provided in a peripheral wall of the process chamber and through which infrared energy radiated from the heat-processed object support member can be transmitted
Implementation Method 2
A heater 13 including a filament and a filament power supply is contained inside a heat-processed object support member (susceptor) 12
Implementation Method 3
A substrate 14 is heated by applying a predetermined voltage to the filament by the filament power supply to accelerate thermoelectrons generated from the filament to bombard them onto the heat-processed object support member 12 to generate heat
Data Source
AI summary
A heating process apparatus includes a process chamber, a heat-processed object support member provided in the process chamber for heating a substrate disposed thereon, a cap for covering the substrate disposed on the heat-processed object support member, a heater for heating the heat-processed object support member, a temperature measuring unit for measuring the temperature of the heat-processed object support member, and a controller for controlling the heater. A first measuring unit measures a temperature of the cap, and the controller controls the heater so as to set the cap temperature to a predetermined temperature. A second measuring unit measures a temperature of the heat-processed object support member, and the controller turns off the heater when the temperature of the heat-processed object support member exceeds an over-heat critical temperature.