Spin Chuck Speed Control for Recovery Cup Contamination
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Solution Overview
Problem
In semiconductor manufacturing, chemical liquid recovery cups are often contaminated due to the discharge of processing liquids during substrate processing, leading to inefficiencies and cleanliness issues.
Innovation Solution
A substrate processing method and apparatus that adjust the rotational speed of the spin chuck in conjunction with height changes of recovery cups, ensuring that processing liquids are directed and recovered efficiently, minimizing contamination by reducing rotational speed during transient periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the spin chuck rotates at high speed during processing liquid discharge, then the processing liquid is efficiently discharged from the substrate, but the recovery cup is contaminated by misplaced liquid
Solution Approach 1:
The patent applies dynamics by making the spin chuck's rotational speed variable rather than constant. The rotational speed is adjusted according to the operational phase: high speed during processing liquid discharge for efficient removal, and reduced speed during recovery cup positioning to prevent contamination. This dynamic speed adjustment resolves the contradiction between discharge efficiency and contamination prevention.
Solution Approach 2:
The patent changes the parameter of rotational speed at different stages of the processing cycle. By reducing the rotational speed during the transient period when recovery cups are positioned, the centrifugal force is minimized, preventing processing liquid from being misplaced into wrong recovery cups. This parameter change strategy effectively prevents contamination while maintaining high discharge efficiency during appropriate phases.
2Object-affected harmful factors
If the rotational speed is reduced during recovery cup height change, then contamination is prevented, but process speed is delayed
Solution Approach 1:
The patent implements periodic action by alternating between high-speed rotation phases and reduced-speed phases in a regular cycle. High speed is used during processing liquid discharge, then speed is reduced during recovery cup positioning, and then increased again for the next discharge phase. This periodic variation in rotational speed prevents contamination during critical moments while minimizing overall process delay.
Solution Approach 2:
The patent applies the skipping principle by rapidly transitioning through the speed reduction phase during recovery cup positioning. The rotational speed is reduced only for the minimal necessary duration to prevent contamination, then immediately increased again to resume efficient processing. This minimizes the time loss while still achieving the contamination prevention goal.
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 minimizes process delays and maintains cleanliness by ensuring that each recovery cup receives the intended liquid, preventing cross-contamination and optimizing the overall processing speed.
Implementation Method 1
a processing liquid supplied to the substrate is scattered into one of the recovery cups by a centrifugal force when the substrate is rotated
Data Source
AI summary
An embodiment of the present invention provides a substrate processing method. The substrate processing method, which performs a liquid processing process by injecting a processing liquid on a substrate on a spin chuck disposed inside a plurality of recovery cups that are disposed in multiple layers, includes: in a transitional period of time in which height change of any one of the recovery cups occurs, adjusting rotational speed of the spin chuck, which is configured to support the substrate, in conjunction with the height change of the recovery cup.