Process Chamber Cooling with Pulsed Coolant to Limit Thermal Stress
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Solution Overview
Problem
Rapid cooling of process chamber components can cause damage due to thermal stress, leading to increased downtime and decreased efficiency in substrate processing systems, as existing methods are labor-intensive and slow.
Innovation Solution
Implementing a method that reduces heater power and uses a pulsed coolant flow with a duty cycle to control the cooling rate of process chamber components, allowing them to reach a temperature just above the coolant temperature before reducing the coolant flow to zero, thereby preventing thermal stress on components with different coefficients of thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rapid cooling is applied to process chamber components, then cooling time is reduced and productivity is improved, but thermal stress damages the component and bonding materials
Solution Approach 1:
The patent applies periodic action by using pulsed coolant flow instead of continuous flow. The coolant is delivered in pulses with specific duty cycles (e.g., 10% to 50%) and frequencies (e.g., 0.1 Hz to 10 Hz), creating periodic cooling action that allows thermal equilibrium to be maintained while still achieving efficient heat removal. This periodic approach prevents the continuous thermal stress that causes bonding material failure while maintaining productive cooling rates.
Solution Approach 2:
The patent implements dynamics by making the coolant flow rate variable rather than constant. The system dynamically adjusts the duty cycle and frequency of pulsed coolant flow based on real-time temperature measurements from sensors. This dynamic control allows the cooling rate to adapt to the component's thermal state, preventing excessive thermal gradients that lead to stress and damage while optimizing cooling efficiency at different stages of the cooling process.
2Reliability
If manual stepwise cooling is used to prevent thermal stress, then component integrity is maintained, but labor intensity increases and downtime increases
Solution Approach 1:
The patent applies self-service by implementing an automated control system that uses temperature sensors and feedback control to manage the cooling process without manual intervention. The system automatically adjusts pulsed coolant flow parameters based on measured temperatures, eliminating the need for operators to manually monitor and adjust cooling steps. This automation maintains component integrity through precise control while significantly reducing labor intensity and overall downtime compared to manual stepwise cooling.
Solution Approach 2:
The patent implements feedback control by using temperature sensors to continuously monitor the component's temperature and using this information to adjust the pulsed coolant flow in real-time. The feedback loop compares measured temperature against target temperature profiles and modifies the duty cycle and frequency of coolant pulses accordingly. This feedback mechanism ensures component integrity is maintained while optimizing cooling speed, reducing downtime compared to manual methods.
3Productivity
If continuous coolant flow is used for cooling, then cooling efficiency is improved, but thermal stress and component damage occur
Solution Approach 1:
The patent replaces continuous coolant flow with periodic pulsed flow to eliminate thermal stress while maintaining cooling efficiency. By delivering coolant in controlled pulses with appropriate duty cycles and frequencies, the system achieves effective heat removal through intermittent cooling action. This periodic approach prevents the sustained thermal gradients that cause stress and damage in continuous cooling, while the high peak flow rates during pulses maintain overall cooling efficiency.
Solution Approach 2:
The patent applies parameter changes by transforming the coolant flow from a continuous constant parameter to a dynamically varying pulsed parameter. The system modifies flow rate, duty cycle, and frequency parameters based on real-time temperature conditions. This parameter transformation allows the cooling system to operate efficiently at high peak rates while averaging out thermal stress through periodic interruption, thereby maintaining both cooling efficiency and component integrity.
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 method allows for controlled cooling of process chamber components, preventing damage and reducing downtime by maintaining efficient processing without the need for continuous user monitoring.
Implementation Method 1
a heater disposed proximate a surface of the process chamber component to provide heat to the component
Implementation Method 2
coolant channels to cool the component from a typical operating temperature (e.g. about 90 degrees Celsius), a heat source that heats the component may be shut off and a coolant is flowed through the coolant channels to extract heat from the component
Implementation Method 3
a coolant is flowed through the coolant channels to extract heat from the component
Data Source
AI summary
Methods for cooling process chamber components are provided herein. In some embodiments, a method of cooling a process chamber component may include reducing a power provided to a heater disposed proximate a surface of the process chamber component to reduce an amount of heat provided to the component by the heater; providing a coolant to coolant channels disposed within the process chamber component using a pulsed flow having a duty cycle until the process chamber component reaches a temperature that is less than or equal to a predetermined magnitude above a temperature of the coolant; and after the process chamber component reaches the temperature less than or equal to the predetermined magnitude above a temperature of the coolant, reducing the duty cycle of the pulsed flow of the coolant to zero.