Pump Error Volume Compensation for Dispense Accuracy
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Solution Overview
Problem
Fluid pumps used in semiconductor processing face challenges in accurately dispensing fluids due to system compliance, which leads to errors in the amount and rate of fluid dispensed, affecting the uniformity of coatings on semiconductor wafers.
Innovation Solution
A method and system that compensate for compliance errors by determining the error volume based on fluid properties and system compliance, using a correlation between fluid viscosity and error volume, and controlling the dispense motor to move the piston to the correct position to achieve the intended dispense volume, incorporating user-specified error volumes if necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the pump operates without compliance compensation, then the system is simpler and faster, but the dispense volume accuracy deteriorates
Solution Approach 1:
The system performs preliminary calibration to establish compliance characteristics before actual dispensing operations. The controller stores compliance data and uses it to pre-calculate compensation values, which are then applied during normal operation to maintain accuracy without adding real-time computational complexity.
Solution Approach 2:
The system incorporates feedback mechanisms where the controller monitors actual dispense volumes and compares them against target values. Based on this feedback, the controller adjusts piston position commands to compensate for compliance effects, ensuring accurate dispensing while managing system complexity through iterative correction.
2Manufacturing precision
If compliance compensation is implemented, then the dispense volume accuracy improves, but the computational time and processing complexity increase
Solution Approach 1:
Compliance characteristics are determined and stored in advance through calibration procedures. The controller uses pre-stored compliance data and lookup tables to quickly determine compensation values during actual dispensing operations, avoiding time-consuming real-time calculations while maintaining high accuracy.
Solution Approach 2:
The system changes operational parameters dynamically by adjusting piston position commands based on pre-determined compliance characteristics and fluid properties. The controller modifies dispensing parameters such as piston displacement distance and speed to compensate for compliance effects, achieving accurate dispensing with minimal computational overhead during operation.
3Manufacturing precision
If the pump system accounts for system compliance, then the coating uniformity on wafers improves, but the device complexity increases
Solution Approach 1:
The controller is designed to perform multiple functions: it manages the pumping operation, compensates for compliance effects, controls piston position and speed, and ensures coating uniformity. By integrating these functions into a single multi-functional control system, the patent reduces overall system complexity while achieving the desired coating uniformity.
Solution Approach 2:
The system performs self-compensation by automatically determining compliance characteristics and applying corrections without external intervention. The controller monitors dispensing parameters and autonomously adjusts piston position to maintain coating uniformity, reducing the need for complex external calibration systems or manual adjustments.
Data Source
AI summary
A pumping system that accurately dispenses fluid using a pump, including reducing the error in the amount of a fluid a pump dispenses by correcting for the compliance of a dispense system.