Dispense Flow Synchronization for Gas Bubble Detection
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Solution Overview
Problem
In microelectronic workpiece manufacturing, dispense systems face challenges in maintaining uniformity and consistency due to gas bubbles, which affect flow rate stability and filter performance, leading to defects and variations in coating thickness.
Innovation Solution
The use of pressure and flow rate sensors to detect and quantify gas bubbles by measuring delays between flow change events and flow rate changes, allowing for synchronization of dispense systems with substrate rotation to achieve target uniformity and control of dispense parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If gas bubbles are present in the dispense system, then the liquid becomes compressible causing delay between pressure change and flow rate change, but this degrades the stability of the dispense rate
Solution Approach 1:
The system performs preliminary degassing of the liquid before dispensing to remove gas bubbles that would cause compressibility and flow rate delays. This preventive action ensures the liquid remains incompressible and maintains stable dispense rates throughout the process
Solution Approach 2:
The system uses pressure sensors and flow rate sensors to monitor the dispense process in real-time, detecting delays between pressure changes and flow rate responses that indicate gas bubble presence. This feedback enables corrective actions to maintain dispense rate stability
2Reliability
If gas bubbles are present in the liquid, then they compress under increased pressure causing flow rate delays, but they also block filter membrane channels reducing filter performance
Solution Approach 1:
The system extracts gas bubbles from the liquid through degassing processes before the liquid enters the filter and dispense system. This removal prevents bubbles from blocking filter channels and causing flow rate delays, maintaining both filter performance and flow stability
Solution Approach 2:
The system performs preliminary degassing of the liquid before it reaches the filter and dispense components. This advance removal of gas bubbles prevents their harmful effects on filter performance and flow rate control during the actual dispensing process
3Manufacturing precision
If gas bubbles are present in the dispense system, then they cause polymer components to drop out of solution, but they also serve as nucleation sites for particles to aggregate into larger defects
Solution Approach 1:
The system extracts gas bubbles from the liquid before dispensing to prevent their role as nucleation sites for particle aggregation. This removal eliminates a primary source of defects and maintains coating uniformity by preventing particle formation
Solution Approach 2:
The system transforms the harmful presence of gas bubbles into a detectable signal by monitoring flow rate delays caused by bubble compression. This allows the system to identify and respond to bubble presence, converting a harmful factor into a useful diagnostic indicator
4Manufacturing precision
If the dispense volume is decreased for advanced process flows, then the acceptable combinations of variables to provide uniform thickness decrease, but tighter uniformity control is needed as film thickness and critical dimension budgets shrink
Solution Approach 1:
The system uses real-time feedback from pressure and flow rate sensors to continuously monitor and adjust dispense parameters, maintaining uniform coating thickness even with reduced dispense volumes. This closed-loop control manages the increased complexity by automating parameter adjustments
Solution Approach 2:
The system dynamically changes process parameters such as pressure, flow rate, and spin speed based on real-time conditions and synchronized control, enabling uniform coating deposition with reduced dispense volumes while managing control complexity through coordinated parameter adjustment
5Reliability
If pressure and flow rate sensors are used to detect gas bubbles by measuring delays, then the stability and consistency of the dispense process is enhanced, but the device complexity increases
Solution Approach 1:
The system uses pressure and flow rate sensors to provide real-time feedback on dispense process conditions, detecting gas bubble presence through measured delays. This feedback mechanism enhances process reliability by enabling continuous monitoring and corrective action
Solution Approach 2:
The system performs self-diagnosis by automatically detecting gas bubbles through sensor measurements of flow rate delays and autonomously adjusting parameters to maintain stable dispensing, reducing the need for external intervention and manual monitoring
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 approach enhances the stability and consistency of the dispense process, reducing defects and improving the uniformity of coating thickness by accurately detecting gas bubbles and adjusting dispense parameters in real-time.
Implementation Method 1
pressure and flow rate sensors to detect and quantify gas bubbles by measuring delays between flow change events and flow rate changes
Implementation Method 2
pressure and flow rate sensors to detect and quantify gas bubbles by measuring delays between flow change events and flow rate changes
Implementation Method 3
bubbles present anywhere in the dispense system will compress under increased pressure. As such, the presence of gas bubbles in the liquid causes a delay between applied pressure and flow rate change
Data Source
AI summary
Embodiments are described herein to monitor and synchronize dispense systems for processing systems. For one embodiment, pressure and flow rate sensors are used to determine a delay between a flow change event and an increase in flow rate, and this delay is used to detect defects or conditions within the dispense system. For one embodiment, dispense system operation is synchronized using flow rate sensors. For one embodiment, simulation models or complex dispense profiles based upon combined pressure/flow/spin/concentration sensor data are used to enable complex process recipes. For one embodiment, dispense-to-dispense pressure and/or flow rate measurements are used to detect dispense parameters and defects. For one embodiment, cameras and image processing are used to detect flow rates from the dispense nozzle, and dispense-to-dispense measurements are used to detect dispense parameters and defects. One or more of the disclosed embodiments can be used in processing systems for microelectronic workpieces.