CMP Platen Temperature Control for Stable Removal Rates
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Solution Overview
Problem
Current chemical mechanical polishing systems face challenges in maintaining precise platen temperature control, leading to suboptimal removal rates and fluid breakdown during semiconductor substrate manufacturing, especially with narrower line widths requiring tighter temperature control.
Innovation Solution
A chemical mechanical polishing system incorporating a platen temperature control system with a PID controller, fluid controller, and heat exchanger, which senses the polishing surface temperature and adjusts coolant flow through channels in the platen to maintain the temperature within a predefined operational window.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If platen temperature is increased to improve removal rate, then polishing productivity increases, but polishing fluid breaks down yielding unacceptable results
Solution Approach 1:
The system employs a temperature sensor to continuously monitor the polishing surface temperature and feeds this information back to a PID controller. The controller adjusts the coolant flow rate dynamically based on the temperature feedback, ensuring the temperature remains within the operational window and preventing fluid breakdown while maintaining optimal removal rates.
Solution Approach 2:
The system changes the coolant flow rate parameter dynamically in response to temperature variations. By adjusting this parameter, the system maintains the polishing surface temperature within the narrow operational window, preventing both insufficient removal rates and fluid breakdown.
2Reliability
If platen temperature is decreased to prevent fluid breakdown, then polishing fluid stability improves, but removal rate becomes unacceptably low
Solution Approach 1:
The temperature sensor continuously monitors the polishing surface temperature and provides feedback to the PID controller. When temperature drops below the operational window, the controller reduces coolant flow to prevent excessive cooling, thereby maintaining sufficient removal rates while preventing fluid breakdown.
Solution Approach 2:
The system transitions from static temperature control to dynamic control by continuously adjusting coolant flow based on real-time temperature conditions. This dynamic adjustment allows the system to optimize both removal rate and fluid stability under varying operational conditions.
3Measurement precision
If PID control with dynamic coolant adjustment is implemented to maintain precise temperature, then temperature control precision improves, but device complexity increases
Solution Approach 1:
The PID controller receives continuous temperature feedback from the sensor and automatically adjusts coolant flow without requiring manual intervention. This automated feedback loop achieves precise temperature control while minimizing the need for complex manual control mechanisms.
Solution Approach 2:
The control system is self-regulating, using the temperature sensor and PID controller to automatically adjust coolant flow based on actual temperature conditions. This self-service capability reduces the need for external monitoring and manual adjustment, simplifying overall system operation despite the added control components.
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 ensures stable polishing rates by maintaining the polishing surface temperature within a defined range, preventing fluid breakdown and enhancing the precision and reliability of semiconductor substrate fabrication.
Implementation Method 1
a heat exchanger. The flow controller is configured to control an amount of fluid provided from the heat exchanger to channels of the platen
Implementation Method 2
The platen temperature control system includes a PID controller, a fluid controller, and a heat exchanger. The flow controller is configured to control an amount of fluid provided from the heat exchanger to channels of the platen in response to instructions provided by the PID controller
Data Source
AI summary
Embodiments of a system and method for polishing substrates are provided. In one embodiment, a polishing system is provided that includes a polishing module having a platen, and a platen temperature control system. The platen temperature control system includes a PID controller, a fluid controller, and a heat exchanger. The flow controller is configured to control an amount of fluid provided from the heat exchanger to a channels of the platen in response to instructions provided by the PID controller.