Microwave Plasma Chamber Shutdown Sequence to Reduce Substrate Particles
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Solution Overview
Problem
Existing plasma processing methods result in the formation of particles on substrates due to the deposition of reaction products during plasma processing, which can affect film quality and substrate cleanliness.
Innovation Solution
A plasma processing apparatus and method that utilizes microwave radiation units arranged both centrally and peripherally within a processing chamber, with controlled shutdown sequences to manage plasma generation and minimize particle deposition on the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If microwave radiation units are arranged both centrally and peripherally to improve plasma uniformity, then film quality is improved, but device complexity increases
Solution Approach 1:
The microwave radiation system is segmented into central and outer peripheral radiation units, allowing independent control of each segment. This segmentation enables optimized plasma distribution across the substrate surface, improving film uniformity while managing system complexity through modular architecture
Solution Approach 2:
Different regions of the processing chamber are provided with different microwave radiation characteristics - central units for core plasma generation and outer peripheral units for edge plasma control. This local differentiation optimizes plasma density distribution and film quality across different substrate regions
2Productivity
If microwave radiation is stopped immediately after plasma processing to improve productivity, then processing time is reduced, but particles are deposited on the substrate
Solution Approach 1:
The system performs preliminary actions by continuing microwave radiation from outer peripheral units after central units are stopped, creating a protective plasma environment that prevents particle deposition during the transition phase, thereby eliminating the need for extended processing time
Solution Approach 2:
The multi-stage shutdown sequence allows the system to rapidly transition through the critical particle-deposition period by quickly stopping central radiation while maintaining outer peripheral radiation, effectively skipping through the harmful phase without sacrificing productivity
3Device complexity
If all microwave radiation units are stopped simultaneously to simplify control, then device complexity is reduced, but particle formation increases
Solution Approach 1:
The control system is segmented into multiple independent control channels for central and outer peripheral units, allowing staged shutdown sequences. This segmentation adds manageable complexity while effectively preventing particle formation through controlled plasma dissolution
Solution Approach 2:
The system employs dynamic control where radiation units are stopped in a specific sequence rather than simultaneously. The control parameters change dynamically during the shutdown process, first stopping central units then outer peripheral units, adapting to the changing plasma conditions to prevent particle generation
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
Reduces the number of particles on the substrate by effectively capturing and removing them through controlled microwave and RF power shutdown strategies, maintaining film quality.
Implementation Method 1
generating plasma from a processing gas using microwaves
Implementation Method 2
microwave radiation units arranged at a central portion and an outer peripheral portion of a ceiling wall of the processing chamber and configured to radiate microwaves
Data Source
AI summary
A plasma processing apparatus for generating plasma from a processing gas using microwaves and performing plasma processing on a substrate is provided. The apparatus includes a processing chamber having a substrate support on which the substrate is placed; a plurality of microwave radiation units arranged at a central portion and an outer peripheral portion of a ceiling wall of the processing chamber and configured to radiate microwaves; and a controller configured to complete microwave radiation from the microwave radiation unit in the central portion upon completion of plasma processing of the substrate and then complete microwave radiation from the microwave radiation units in the outer peripheral portion.