Plasma Density Control for Substrate Mounting Plate Cleaning
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Solution Overview
Problem
In substrate processing apparatuses, the film formed on surrounding structures of the substrate mounting plate is prone to peeling off and generating particles, which can adhere to the substrate, deteriorating the film quality and requiring a method to prevent this peeling without etching the substrate placing surfaces.
Innovation Solution
A substrate processing apparatus is designed with a plasma generator that creates a higher plasma density over the substrate non-placing surface than the substrate placing surfaces, using a cleaning gas in a controlled manner to clean the substrate non-placing surface while avoiding etching of the substrate placing surfaces, by adjusting the plasma density and radiation hole areas to ensure effective cleaning without damaging the substrate mounting plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If gas is supplied toward the substrate mounting plate to form a film on the substrate, then the film formation on the substrate is achieved, but the film is also formed on the surrounding structure which may peel off and generate particles
Solution Approach 1:
The invention applies different plasma densities to different regions of the substrate mounting plate. Specifically, the plasma density over the substrate non-placing surface (surrounding structure) is made higher than over the substrate placing surfaces. This local differentiation allows the surrounding structure to be cleaned effectively while preventing etching of the substrate placing surfaces, thus resolving the contradiction between film quality and particle generation.
2Object-generated harmful factors
If cleaning gas is supplied to clean the surrounding structure, then particle generation is prevented, but the substrate placing surfaces may be etched
Solution Approach 1:
The invention implements spatially selective plasma cleaning by controlling the plasma generator to create higher plasma density specifically over the substrate non-placing surface while maintaining lower plasma density over the substrate placing surfaces. This local quality differentiation enables effective cleaning of the surrounding structure without causing etching damage to the substrate placing surfaces.
Solution Approach 2:
The invention changes the plasma density parameter differentially across different regions of the substrate mounting plate. By adjusting the plasma density to be higher over the non-placing surface and lower over the placing surfaces, the system achieves effective cleaning while preventing etching, thus resolving the contradiction between particle prevention and surface integrity.
3Productivity
If the substrate mounting plate is rotated to process multiple substrates, then throughput is improved, but the surrounding structure accumulates film that peels and generates particles
Solution Approach 1:
The invention performs preliminary cleaning action on the substrate non-placing surface by maintaining higher plasma density in this region. This preliminary cleaning prevents film accumulation before it can peel and generate particles, allowing the substrate mounting plate to be rotated for processing multiple substrates without the harmful effect of particle generation from accumulated film.
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 approach effectively cleans the substrate non-placing surface without etching the substrate placing surfaces, maintaining uniform heating and preventing particle generation, thus enhancing film quality and throughput.
Implementation Method 1
a plasma generator configured to generate plasma such that a plasma density over the substrate non-placing surface is higher than a plasma density over the plurality of the substrate placing surfaces
Implementation Method 2
a heater placed below the substrate mounting plate
Data Source
AI summary
Described herein is a technique capable of cleaning a surrounding structure of a substrate placing surface in an apparatus. According to one aspect of the technique, there is provided a substrate processing apparatus including: a process chamber in which a substrate is processed; a substrate mounting plate provided with a substrate non-placing surface and a plurality of substrate placing surfaces; a rotator configured to rotate the substrate mounting plate; a plasma generator configured to generate plasma such that a plasma density over the substrate non-placing surface is higher than a plasma density over the plurality of the substrate placing surfaces; a process gas supplier configured to supply a process gas into the process chamber; a cleaning gas supplier configured to supply a cleaning gas into the process chamber; and a heater placed below the substrate mounting plate.