Substrate Mounting Table With Localized Surface Roughness
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Solution Overview
Problem
In plasma-based processes for semiconductor manufacturing, existing substrate mounting configurations either lead to arcing due to electrical floating of substrates or accumulation and peeling of reaction products, causing particle generation.
Innovation Solution
A substrate mounting table with a mirror-treated surface for the substrate mounting portion and an unevenly treated edge portion to prevent arcing and improve film adhesion, reducing positional deviations and particle formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a roughened portion with surface roughness Ra of 2 μm or more and 6 μm or less is formed on the substrate mounting surface, then film adhesion is improved, but the substrate electrically floats from the stage causing potential difference and arc discharge
Solution Approach 1:
The patent applies different surface roughness characteristics to different regions of the substrate mounting surface. The central substrate mounting area has a first surface roughness (Ra of 0.3-1.5 μm) that prevents electrical floating, while the peripheral region has a second surface roughness (Ra of 1.5-6 μm) that enhances film adhesion. This local differentiation resolves the contradiction by allowing each region to optimize for its specific function.
2Reliability
If a smooth surface is formed on the substrate mounting surface, then arc discharge is suppressed, but reaction products adhere and accumulate on the stage surface causing particle generation
Solution Approach 1:
The patent differentiates surface properties between the central mounting area and peripheral regions. The central area maintains smoothness (Ra of 0.3-1.5 μm) to prevent arc discharge, while peripheral areas have increased roughness (Ra of 1.5-6 μm) to reduce reaction product accumulation and particle generation through enhanced plasma distribution.
3Productivity
If high frequency power is applied to create plasma, then the plasma-based process is enabled, but arc discharge occurs due to potential difference between substrate and stage
Solution Approach 1:
The patent optimizes surface roughness in the central substrate mounting region (Ra of 0.3-1.5 μm) to ensure good electrical contact and prevent substrate floating during plasma processing. This localized surface treatment allows high frequency power application for plasma generation while preventing arc discharge through improved electrical connectivity.
Data Source
AI summary
There is provided a substrate mounting table for use in a plasma-based processing apparatus that performs a plasma-based process on a substrate inside a processing container, which includes a substrate mounting portion having a front surface subjected to a mirroring treatment and on which the substrate is mounted, and an edge portion located around the substrate mounting portion and treated to have an uneven shape.