Polishing Pad Temperature Control via Active Liquid Flow Regulation
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Solution Overview
Problem
Existing pad temperature adjustment systems face challenges in precisely controlling the flow amount of liquid supplied to a polishing pad, due to back pressure from plant facilities and limitations in flow amount adjustment apparatuses, which can affect the consistency and precision of wafer polishing rates in semiconductor manufacturing.
Innovation Solution
A system incorporating a heat exchanging member and a liquid supply unit with a pump device, needle valve, and control device that adjusts the flow amount of liquids through heating and cooling liquid supply lines, using pressure regulators, valves, and pulsation attenuators to maintain precise control over the liquid flow, enabling wide-range flow adjustments from small to large flow regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a flow amount adjustment apparatus is used to control liquid flow through a liquid supply line connected to a plant facility, then the flow amount can be adjusted, but the control precision deteriorates due to back pressure from plant facilities
Solution Approach 1:
The patent introduces a liquid supply unit as an intermediary device between the plant facility and the pad contact member. This unit includes a pump that actively controls liquid supply, isolating the temperature control system from back pressure effects. The pump acts as a mediator that maintains precise flow control regardless of downstream pressure conditions, thereby resolving the contradiction between adjustability and control precision.
Solution Approach 2:
The patent replaces passive flow control mechanisms (which are susceptible to back pressure) with an active pump-based system. The pump uses mechanical power to maintain consistent liquid flow rates, substituting the unreliable passive mechanical flow control with an actively controlled system that can compensate for pressure variations and maintain precision across wide flow ranges.
2Device complexity
If a conventional flow control valve is used, then the structure remains simple, but the flow amount control precision deteriorates in small flow amount region
Solution Approach 1:
The pump serves as an intermediary that enables precise flow control in the small flow amount region by providing active control capability. Rather than relying solely on valve positioning, the pump can precisely meter liquid delivery, maintaining control precision even when flow rates are low, while the overall system structure remains relatively simple through integrated control.
3Speed
If the liquid flow amount is increased to improve temperature control response, then the temperature adjustment speed improves, but the energy consumption increases
Solution Approach 1:
The patent implements dynamic flow control where the pump adjusts liquid flow rates based on real-time temperature feedback from the polishing pad. During rapid temperature changes, higher flow rates are used to improve response speed. When temperature stabilization is achieved, flow rates are reduced to minimize energy consumption. This dynamic adjustment resolves the contradiction between temperature adjustment speed and energy efficiency.
Solution Approach 2:
The system incorporates temperature sensors that continuously monitor the pad temperature and feed this information back to the pump controller. Based on the temperature deviation from the target value, the controller dynamically adjusts the pump speed and flow rate, enabling fast temperature adjustment when needed while reducing energy consumption during steady-state operation.
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 allows for precise control of the pad surface temperature, ensuring consistent wafer polishing rates by effectively managing the flow of liquids, thereby enhancing the stability and reliability of semiconductor manufacturing processes.
Implementation Method 1
a heat exchanging member that is capable of exchanging heat with a surface of a pad
Implementation Method 2
a pump device that adjusts a flow amount of a liquid flowing through a heating liquid supply line
Implementation Method 3
a needle valve that is attached to a cooling liquid supply line
Data Source
AI summary
A system (5) includes a heat exchanging member (11) and a liquid supply unit (30). The liquid supply unit (30) includes a pump device (32) that adjusts the flow amount of a liquid flowing through a heating liquid supply line (HSL), a needle valve (MNV) that is attached to a cooling liquid supply line (CSL), and a control device (40) that controls operations of the pump device (32) and the needle valve (MNV).