Electric Field Membrane Filter for IC Chemical Solutions
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Solution Overview
Problem
The increasing integration and miniaturization of integrated circuits lead to pattern defects due to fine-sized impurities in photoresist solutions during the patterning process, as existing filters struggle to effectively remove both small and large-sized charged particles.
Innovation Solution
A filter structure comprising a membrane unit with a cathode, an anode, and an insulating layer, applied with an electric field to trap positively and negatively charged particles, combined with a polymer membrane to filter larger impurities, ensuring the removal of fine-sized charged particles while allowing photoresist particles to pass through.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional filter is used to remove impurities from photoresist solution, then large-sized particles are filtered out, but fine-sized charged particles cannot be effectively removed
Solution Approach 1:
The filter structure is divided into multiple membrane units stacked together, each membrane unit containing both a polymer membrane for mechanical filtration and an electric field membrane with oppositely charged electrodes for electrostatic attraction. This segmentation allows different filtration mechanisms to work in parallel, effectively removing both large and fine-sized particles without requiring a single complex filter system.
Solution Approach 2:
The invention combines two different membrane types (polymer membrane and electric field membrane) with distinct filtration mechanisms into a single composite filter structure. The polymer membrane provides mechanical filtration for larger particles, while the electric field membrane with charged electrodes provides electrostatic filtration for fine-sized charged particles, achieving comprehensive filtration performance.
2Manufacturing precision
If the filter pore size is reduced to capture fine particles, then filtering precision improves, but photoresist particles may be blocked
Solution Approach 1:
Different regions of the filter structure have different pore sizes and filtration mechanisms. The polymer membrane has larger pores suitable for photoresist particles, while the electric field membrane has smaller pores with charged electrodes that attract fine impurities. This local differentiation allows fine particle removal without blocking photoresist flow.
Solution Approach 2:
The invention changes the filtration parameter from purely mechanical size-based filtration to a combination of mechanical filtration and electrostatic attraction. By applying electric fields through charged electrodes, the filter can attract fine charged particles regardless of pore size, maintaining high flow rates while improving impurity removal efficiency.
3Device complexity
If only mechanical filtration is used, then the filter structure is simple, but charged particles of both positive and negative charges cannot be effectively trapped
Solution Approach 1:
The electric field membrane structure serves multiple functions simultaneously: it provides a physical filtration barrier through its membrane structure, generates electrostatic attraction fields through oppositely charged electrodes, and creates ionization regions that can charge and trap particles. This multi-functionality enables effective removal of both positively and negatively charged particles without requiring separate filter systems.
Solution Approach 2:
The invention replaces purely mechanical filtration with an electrostatic field-based filtration mechanism. Instead of relying solely on physical pore blocking, the charged electrodes generate electric fields that actively attract and trap charged particles, providing more effective removal of fine charged impurities while maintaining structural simplicity.
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 solution effectively filters impurities of various sizes from chemical solutions, reducing pattern defects in integrated circuits by trapping charged particles and larger impurities, while allowing photoresist particles to be used in the patterning process, thus enhancing the quality of integrated circuit manufacturing.
Implementation Method 1
when an electric field is applied between the cathode and the anode while the chemical solution introduced through the inlet passes through the first membrane structure, impurities having both positively charged particles and negatively charged particles in the chemical solution are trapped in the first membrane structure
Implementation Method 2
an insulating layer between the cathode and the anode, the insulating layer being configured to electrically separate the cathode from the anode
Implementation Method 3
a polymer membrane received inside the filter housing and including a plurality of pores
Data Source
AI summary
A filter structure for chemical solution used in manufacturing an integrated circuit includes: a first membrane structure comprising a plurality of membrane units, each comprising a cathode comprising a plurality of first openings, an anode comprising a plurality of second openings, and an insulating layer between the cathode and the anode; and a filter housing configured to receive the first membrane structure therein, the filter housing comprising an inlet through which the chemical solution is introduced and an outlet through which the chemical solution is discharged. The first membrane structure is configured such that when an electric field is applied between the cathode and the anode while the chemical solution introduced through the inlet passes through the first membrane structure, impurities having both positively charged particles and negatively charged particles in the chemical solution are trapped in the first membrane structure.