Substrate Processing Electrostatics for Scattered Droplet Capture
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in preventing contamination of substrates during etching and cleaning processes, particularly due to scattering liquid droplets.
Innovation Solution
A substrate processing apparatus is designed with a support unit for rotating substrates, a chemical liquid supply nozzle, a collection cup, and a charging unit that captures droplets scattering on the substrate by being charged with opposite charges to the chemical liquid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a chemical liquid is supplied to the substrate during etching/cleaning processes, then the substrate processing effectiveness is improved, but liquid droplets scatter and cause contamination
Solution Approach 1:
A charging unit is introduced as an intermediary component between the chemical liquid supply and the substrate. This charging unit imparts electrical charge to scattered liquid droplets, enabling them to be captured by oppositely charged collection electrodes, thus preventing contamination while maintaining processing effectiveness
Solution Approach 2:
The patent replaces purely mechanical/physical containment methods with an electrostatic control mechanism. By using electrical charges to attract and capture scattered droplets, the system achieves more effective contamination prevention compared to traditional mechanical barriers or containment structures
2Quantity of substance
If a collection cup is used to collect chemical liquid, then liquid collection is improved, but scattered droplets still contaminate the substrate
Solution Approach 1:
The charging unit serves as a mediator that transforms neutral liquid droplets into charged particles. This transformation enables the collection system to capture even scattered droplets that would otherwise escape conventional collection cups, thereby improving both collection efficiency and contamination prevention
3Manufacturing precision
If the substrate is rotated at high speed for chemical liquid spreading, then chemical liquid distribution is improved, but droplet scattering and contamination increase
Solution Approach 1:
The patent converts the harmful effect of high-speed rotation (droplet scattering) into a beneficial one by using electrostatic fields. The charging unit captures scattered droplets that would otherwise cause contamination, transforming the harmful scattering phenomenon into a controllable process where scattered droplets are systematically collected rather than causing damage
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
The apparatus effectively prevents contamination by capturing and collecting chemical liquid droplets that scatter on the substrate, ensuring a clean processing environment.
Implementation Method 1
The charging unit is configured to capture droplets of the chemical liquid that collide with the substrate and scatter, and is charged with charges opposite to charges of the chemical liquid
Implementation Method 2
a substrate is fixed to a support module capable of processing a single substrate, and then a chemical is supplied to the substrate through a nozzle while rotating the substrate such that the chemical is spread across the entire surface of the substrate by the centrifugal force
Data Source
AI summary
A substrate processing apparatus includes a support unit configured to support a substrate and be rotatable, a chemical liquid supply nozzle configured to supply a chemical liquid to a chemical liquid supply area of the substrate, and a charging unit disposed adjacent to the substrate. The charging unit is disposed adjacent to the chemical liquid supply nozzle, and is charged with charges opposite to charges of the chemical liquid.