Charged Liquid Filtration for Substrate Static Neutralization
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in controlling the charged state of substrates during semiconductor manufacturing, leading to contamination and defects due to static electricity and particle attachment, as existing methods either neutralize the processing liquid or fail to effectively manage static charges on the substrate.
Innovation Solution
A substrate processing apparatus with a charge amount control unit, comprising a filter unit charged with positive or negative charges and a control valve to adjust the flow rate of the processing liquid, coupled with a detection unit to monitor the substrate's charged state, allowing for precise control of the processing liquid's charge to match the substrate's state, thereby neutralizing static electricity and preventing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a porous filter charged with predetermined electric charges is used to remove impurities from processing liquid, then impurity removal capability is improved, but the filter itself becomes a source of static electricity that can cause particle attachment and substrate contamination
Solution Approach 1:
The invention converts the harmful static electricity generated by the charged filter into a beneficial effect by intentionally charging the processing liquid with opposite polarity charges. The filter's static charge is used to charge the processing liquid, which then neutralizes substrate static electricity, transforming the harmful filter static into a useful charge control mechanism.
Solution Approach 2:
The processing liquid serves as an intermediary medium that transfers charge control from the filter to the substrate. Instead of the filter directly interacting with the substrate, the charged processing liquid acts as a mediator, carrying the opposite charge to neutralize substrate static electricity during the coating process.
2Reliability
If the processing liquid is charged to neutralize substrate static electricity, then substrate contamination is reduced, but precise control of the charge amount becomes difficult
Solution Approach 1:
The invention controls the charge amount of the processing liquid by changing parameters such as flow rate through the filter and contact time with the charged filter surface. By adjusting these parameters, the degree of charging can be precisely controlled to match the substrate's static electricity level, enabling effective neutralization without excessive charging.
3Reliability
If conventional methods coat the nozzle with antistatic material or use additional light sources to neutralize charges, then charge neutralization is achieved, but device complexity increases
Solution Approach 1:
The charged porous filter serves multiple functions: it filters impurities from the processing liquid and simultaneously charges the liquid with opposite polarity to neutralize substrate static electricity. This multi-functionality eliminates the need for separate antistatic coatings or light source units, reducing overall device complexity while maintaining charge neutralization capability.
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
Effectively adjusts the charged state of substrates to prevent electrostatic discharge and defects, ensuring proper processing conditions by actively controlling the charge of the processing liquid based on the substrate's state, enhancing the reliability of semiconductor manufacturing processes.
Implementation Method 1
a filter unit charged with positive charges or negative charges... to control a charge amount of the processing liquid
Implementation Method 2
a detection unit configured to detect a charged state of the substrate
Data Source
AI summary
A substrate processing apparatus includes: a nozzle unit configured to discharge a processing liquid to a substrate; a pipe connected to the nozzle unit and a processing liquid supply unit supplying the processing liquid; a charge amount control unit disposed at the pipe, including a filter unit charged with positive charges or negative charges, and including at least one of a control valve, controlling a flow rate of the processing liquid passing through an inside of the filter unit, and a power supply unit, applying a voltage to the filter unit, to control a charge amount of the processing liquid; and a control unit connected to the charge amount control unit.