ESC Heating Medium Mixing for Fast Wafer Temperature Control
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Solution Overview
Problem
Conventional temperature control systems for semiconductor manufacturing face challenges in efficiently managing temperature variations, leading to high power consumption, thermal shock, and inefficiencies due to the need for abrupt temperature changes and the disturbance of RF power in the chamber.
Innovation Solution
A temperature control system that mixes a low-temperature heating medium cooled through a thermoelectric element with a high-temperature heating medium heated by a heater, using a dual structure of thermoelectric element blocks and heaters to minimize thermal shock and optimize power consumption, and incorporates a heat exchanger to recover residual heat for efficient cooling and heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a single temperature control method (chiller or heater) is used, then the system structure is simple, but the response time is slow and cannot handle rapid temperature variations
Solution Approach 1:
The patent combines both chiller and heater systems into a unified temperature control architecture, allowing simultaneous or alternating operation of cooling and heating functions. This merging enables rapid temperature adjustments by selecting the appropriate component based on whether temperature increase or decrease is needed, while maintaining a integrated system structure that shares common infrastructure.
Solution Approach 2:
The system dynamically switches between chiller and heater operations based on real-time temperature requirements. The control mechanism adjusts which component is active at any given moment, enabling rapid response to temperature variations without requiring a completely redesign of the system architecture.
2Use of energy by moving object
If recovered heating medium is supplied to both cooling and heating tanks, then the system is simple to operate, but power consumption increases significantly
Solution Approach 1:
The system incorporates feedback mechanisms that monitor the temperature and flow characteristics of the recovered heating medium. Based on this feedback, the control system intelligently directs the recovered medium to either the cooling tank or heating tank, optimizing energy utilization. This feedback-driven distribution minimizes unnecessary heating or cooling operations, thereby reducing overall power consumption.
Solution Approach 2:
The recovered heating medium is automatically routed to where it is most needed based on its thermal state. The system self-regulates the distribution without requiring manual intervention, using the thermal energy content of the recovered medium to determine whether it should be used for cooling or heating purposes, thereby optimizing energy efficiency.
3Reliability
If temperature control relies on tunable heater only, then external temperature control is avoided, but power efficiency is degraded and RF power is disturbed
Solution Approach 1:
The patent introduces an external temperature control system comprising chillers and heaters that act as intermediaries to manage the thermal state of the processing chamber. This external system controls the temperature of the heating medium supplied to the electrostatic chuck, thereby indirectly controlling the chamber temperature without requiring internal heaters that would interfere with RF power.
Solution Approach 2:
The invention replaces the mechanical/electrical heater system inside the chamber with a thermodynamic approach using external chillers and heaters that control the heating medium temperature. This substitution eliminates the need for direct electrical heating elements in the chamber, avoiding RF power interference while maintaining reliable temperature control through thermal management of the heating medium.
4Speed
If heating medium flow rate is increased to handle thermal capacity, then temperature control speed improves, but system complexity and energy loss increase
Solution Approach 1:
The system recovers thermal energy from the heating medium after it has passed through the electrostatic chuck. The recovered heating medium, which still contains thermal energy, is redirected to where it can be most effectively utilized - either to pre-cool incoming heating medium in the cooling tank or to supplement heating in the heating tank. This recovery process reduces the energy that would otherwise be wasted and decreases the overall flow rate needed to maintain temperature control speed.
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 system enables rapid and precise temperature control with reduced thermal shock and power consumption, minimizing overshoot and undershoot, while maintaining stable temperatures and optimizing energy efficiency by continuously circulating the heating medium through the chiller and heater units.
Implementation Method 1
a first thermoelectric element block configured to cool and provide the heating medium of the first heating medium tank
Implementation Method 2
a first heater configured to heat the heating medium in the second heating medium tank
Implementation Method 3
a mixer configured to mix a low temperature heating medium and a high temperature heating medium to supply the mixed heating medium to a load
Implementation Method 4
incorporates a heat exchanger to recover residual heat for efficient cooling and heating
Data Source
AI summary
Provided is a temperature control system configured to mix a low temperature heating medium and a high temperature heating medium to supply the heating mediums at a temperature according to a process recipe to an electrostatic chuck (ESC) configured to maintain a temperature and support a wafer in a chamber in which a semiconductor wafer processing process is performed, and a heating medium obtained by mixing a heating medium cooled through a thermoelectric element and a heating medium heated through a heater to a desired target temperature according to a first ratio and a second ratio is provided to a load and recovered from the load, and the heating medium is distributed to the thermoelectric element and the heater according to the first ratio and the second ratio, which are ratios upon the mixing, optimizing power consumption for cooling or heating.