Shower Head Magnet Pillars for Plasma Density Uniformity
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Solution Overview
Problem
Conventional plasma processing apparatuses experience non-uniformity in plasma processing due to varying plasma density distribution across the substrate surface, leading to inconsistent results in semiconductor wafer processing.
Innovation Solution
A plasma processing apparatus and shower head design featuring rod-shaped magnet pillars that can be adjusted to control plasma leakage and density distribution, combined with gas exhaust holes and a driving unit to optimize plasma distribution uniformly across the substrate surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If magnets are installed around the processing chamber to control plasma, then plasma control is improved, but processing uniformity across substrate surface deteriorates
Solution Approach 1:
The patent applies local quality by positioning magnets specifically around the gas exhaust region rather than uniformly around the entire processing chamber. This localized magnetic field configuration allows plasma control where needed (at the exhaust region) while maintaining uniform plasma distribution across the substrate surface, thereby resolving the contradiction between plasma control effectiveness and processing uniformity.
Solution Approach 2:
The patent introduces a specific intermediary structure - the gas exhaust region with localized magnets - that mediates between the conflicting requirements. By placing magnets around the gas exhaust region, the system achieves plasma control through this intermediary zone without directly exposing the substrate area to non-uniform magnetic fields, thus maintaining processing uniformity while still achieving effective plasma control.
2Reliability
If magnets are installed to confine plasma in gas exhaust region, then plasma confinement is improved, but plasma density distribution uniformity deteriorates
Solution Approach 1:
The patent implements local quality by confining magnets to the gas exhaust region only, creating a localized magnetic field that confines plasma where it is needed (at the exhaust) without disrupting plasma density uniformity in the substrate processing area. This selective placement resolves the contradiction between effective plasma confinement and maintaining uniform plasma density distribution.
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 design enhances the uniformity of the plasma process on semiconductor wafers by allowing precise control of plasma density, improving processing consistency and reducing the size of the apparatus while maintaining efficient gas exhaust.
Implementation Method 1
there is also known a technology for confining plasma in a processing space by forming a magnetic field in a gas exhaust region of a processing chamber by magnets so as to allow a gas to pass the gas exhaust region and prevent plasma from passing the gas exhaust region
Implementation Method 2
a shower head for supplying a gas toward a substrate such as a semiconductor wafer in a shower pattern has been conventionally used
Data Source
AI summary
A plasma processing apparatus includes a shower head that is installed within a processing chamber for processing a substrate therein so as to face a mounting table for mounting the substrate thereon and supplies a gas toward the substrate in a shower pattern through a plurality of gas discharge holes provided in a facing surface of the shower head facing the mounting table; a plurality of gas exhaust holes formed through the shower head to be extended from the facing surface of the shower head to an opposite surface from the facing surface; a multiple number of rod-shaped magnet pillars standing upright in a gas exhaust space communicating with the gas exhaust holes on the side of the opposite surface; and a driving unit that varies a distance between the magnet pillars and the gas exhaust holes by moving at least a part of the magnet pillars.