Particle Removal via Ion Sheath Charging in Plasma Chamber
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Solution Overview
Problem
Conventional methods for removing particles in plasma processing apparatuses are ineffective in handling uncharged and electrically neutral particles, causing plasma disturbance and metal contamination, and are difficult to apply to processes requiring uniformity and high credibility, especially for small semiconductor devices.
Innovation Solution
A particle removal apparatus that positively charges particles within the plasma processing chamber using a particle charging control member and a charged particle transfer member, utilizing an ion sheath region to guide positively charged particles towards a gas exhaust port without disturbing the plasma, and employs a control electrode with a negative potential to ensure efficient removal without contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a particle-removing electrode of negative potential is used to collect positively charged particles, then particle removal efficiency is improved, but plasma disturbance and metal contamination occur
Solution Approach 1:
The patent introduces a particle charging control member as an intermediary that positively charges particles using positive ions from the plasma, converting them to a state that can be removed by gas flow without requiring a negative potential electrode. This mediator enables particle removal while avoiding plasma disturbance and metal contamination.
Solution Approach 2:
The patent replaces the electrostatic collection mechanism (negative potential electrode) with a gas flow-based removal mechanism. Particles are charged positively and then carried away by the gas exhaust flow, substituting the mechanical/electrostatic field-based system with a fluid dynamics-based system that avoids contamination.
2Productivity
If conventional particle removal methods are applied, then positively charged particles are removed, but uncharged and electrically neutral particles remain
Solution Approach 1:
The patent changes the electrical charge parameter of particles by introducing a particle charging control member that imparts positive charge to uncharged and neutral particles using positive ions from the plasma. This parameter change enables all particle types to be removed uniformly by the gas flow mechanism.
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 solution enables efficient removal of particles from the plasma processing chamber without affecting plasma generation or causing metal contamination, allowing for practical application to processes requiring high uniformity and credibility, effectively reducing particle attachment to substrates and improving process yield.
Implementation Method 1
particles generated within the chamber are charged positively by positive ions of an ion sheath region formed in a region other than the vicinity of the substrate to be processed
Implementation Method 2
a charged particle transfer member for transferring positively charged particles towards the gas exhaust port via the ion sheath region
Data Source
AI summary
A particle removal apparatus for removing particles from a chamber of a plasma processing apparatus, wherein the chamber is connected to a gas exhaust port and a plasma of a processing gas is generated in the chamber to plasma process a substrate to be processed, includes a particle charging control member for positively charging particles generated within the chamber by positive ions of an ion sheath region formed in a region other than the vicinity of the substrate to be processed, wherein positively charged particles are discharged from the chamber via the gas exhaust port. Therefore, there is no plasma disturbance or metal contamination, and thus can be applied to a practical use.