Process Tube Temperature Control via Dual Feedback
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in achieving precise temperature control within a process tube, particularly in terms of high temperature-rising rate, temperature uniformity, rapid stabilization, and minimizing temperature overshoot.
Innovation Solution
A substrate processing apparatus and method that utilize a controller to adjust the output of a heater based on both internal and external temperature measurements, employing a preliminary output value operation and correction determination to maintain optimal temperature control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-loop PID control is used for temperature control, then the control system is simple, but the temperature control performance (temperature-rising rate, uniformity, stabilization speed) cannot meet requirements
Solution Approach 1:
The patent implements a nested control structure where a first PID controller (inner loop) controls the heater output based on internal temperature, and a second PID controller (outer loop) adjusts the setpoint of the first controller based on external temperature. This nested arrangement allows the system to maintain simplicity while achieving superior temperature control performance by combining fast response to internal changes with adaptive adjustment to external conditions.
Solution Approach 2:
The patent introduces an intermediate control element - the second PID controller that acts as a mediator between the external temperature measurements and the heater control. This intermediary adjusts the setpoint temperature dynamically based on external conditions, allowing the system to adapt to environmental changes without directly affecting the fast-response inner control loop.
2Manufacturing precision
If a cascaded or nested PID control loop is used for improved temperature control, then temperature control performance is improved, but complexity and computational requirements increase
Solution Approach 1:
The patent implements a nested control structure where a first PID controller (inner loop) controls the heater output based on internal temperature, and a second PID controller (outer loop) adjusts the setpoint of the first controller based on external temperature. This nested arrangement allows the system to maintain simplicity while achieving superior temperature control performance by combining fast response to internal changes with adaptive adjustment to external conditions.
3Speed
If the heater output is increased to achieve high temperature-rising rate, then temperature stabilization speed is improved, but temperature overshoot increases
Solution Approach 1:
The patent measures the external temperature in advance and uses the second PID controller to preliminarily adjust the setpoint temperature before the actual heating process. This preliminary action anticipates external thermal conditions and pre-adjusts the control parameters, allowing the system to respond more accurately and reduce overshoot when rapid heating is required.
Solution Approach 2:
The patent employs dual temperature feedback - internal temperature feedback for fast response control and external temperature feedback for adaptive setpoint adjustment. This dual feedback mechanism allows the system to continuously monitor both the actual temperature and environmental conditions, enabling precise control that prevents overshoot while maintaining rapid stabilization.
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 enables effective control of the internal temperature of the process tube, achieving rapid temperature stabilization with minimal overshoot, improved temperature uniformity, and reduced downtime, thus enhancing the quality of substrate processing.
Implementation Method 1
a heater provided outside the process tube to heat the process tube
Implementation Method 2
an internal temperature measuring part provided inside the process tube to measure an internal temperature of the process tube
Implementation Method 3
an external temperature measuring part provided at least partially between the process tube and the heater to measure an external temperature of the process tube
Implementation Method 4
a controller configured to control an output of the heater by utilizing the internal temperature of the process tube and the external temperature of the process tube
Data Source
AI summary
The present disclosure provides a substrate processing apparatus and a substrate processing method, which control an internal temperature of a process tube in a substrate processing process. The substrate processing apparatus includes a process tube configured to provide a process apace in which a processing process for a plurality of substrates laminated in multiple stages is performed, a heater provided outside the process tube to heat the process tube, an internal temperature measuring part provided inside the process tube to measure an internal temperature of the process tube, an external temperature measuring part provided at least partially between the process tube and the heater to measure an external temperature of the process tube, and a controller configured to control an output of the heater by utilizing the internal temperature of the process tube, which is measured in the internal temperature measuring part, and the external temperature of the process tube, which is measured in the external temperature measuring part. The controller includes a preliminary output value operation part configured to operate a preliminary output value of the heater by utilizing the measured internal temperature of the process tube, and a correction determination part configured to determine whether the preliminary output value of the heater is corrected based on the measured external temperature of the process tube.