Substrate Mounting Table Segmented Base for Plasma Processing
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Solution Overview
Problem
The existing substrate mounting tables for plasma processing apparatuses face challenges in maintaining a uniform temperature and high-frequency distribution due to non-uniform thickness and complexity in design, which complicates the attachment and exposure of the electrostatic chuck to corrosive gases.
Innovation Solution
A substrate mounting table design featuring a base with a first surface and a second surface at a preset height, where an insulating film is formed on the second surface to be continuous with the first surface, and an electrostatic chuck is firmly fixed, with an inclined surface to prevent peeling and improve adhesion, using thermally sprayed ceramics for enhanced protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cavity such as a groove is provided in the base to prevent exposure of the insulating film end portion to processing gas, then the insulating film is protected from corrosion, but the structure becomes complicated and the thickness becomes non-uniform
Solution Approach 1:
The base is divided into two distinct surfaces: a first surface that is flat and a second surface that is lower than the first surface by a preset height. The insulating film is formed on the second surface, creating a stepped structure that protects the film from corrosive gas without requiring additional cavities or grooves. This segmentation resolves the contradiction by achieving protection through structural division rather than adding complex protective features.
Solution Approach 2:
Instead of protecting the insulating film end portion by adding a cavity in the same plane (horizontal dimension), the invention uses a vertical dimension approach by creating a second surface that is lower than the first surface. This height difference naturally protects the insulating film end portion from exposure to processing gas, achieving protection without increasing structural complexity.
2Manufacturing precision
If the top surface of the base is made flat to install the electrostatic chuck, then the electrostatic chuck can be firmly attached, but the thickness variability must be compensated by adhesive thickness
Solution Approach 1:
The base is segmented into a first surface (top surface) and a second surface (bottom surface), where the first surface is maintained at a constant height to ensure flatness for electrostatic chuck attachment. The second surface is positioned lower and serves as the mounting surface for the insulating film. This segmentation allows the first surface to be perfectly flat for precise attachment while the thickness variability is absorbed in the base structure itself, eliminating the need for adhesive thickness compensation.
3Adaptability or versatility
If the insulating film is formed on a non-uniform thickness base, then the structure can accommodate thickness variations, but temperature and high frequency control become non-uniform
Solution Approach 1:
The base is divided into a first surface and a second surface with a preset height difference. The insulating film is formed on the second surface, which is positioned lower than the first surface. This segmentation creates a stepped structure where the first surface maintains uniform height for consistent temperature and high frequency distribution, while the second surface accommodates the insulating film. The clear separation between surfaces eliminates the problem of non-uniform film thickness affecting thermal and electrical properties.
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 ensures a flat top surface for secure electrostatic chuck attachment, prevents exposure to corrosive gases, and facilitates uniform temperature and frequency control, enhancing the plasma processing apparatus's performance.
Implementation Method 1
the insulating film forming method includes: thermally spraying the insulating film on the surfaces
Implementation Method 2
The electrostatic chuck is configured by disposing an electrostatic chuck electrode made of tungsten or the like between insulating members such as ceramics. Further, the target substrate is attracted and held by the Coulomb force generated by applying a DC voltage to the electrostatic chuck electrode.
Data Source
AI summary
A substrate mounting table includes an electrostatic chuck for attracting and holding a target substrate and a base for holding the electrostatic chuck thereon. The base includes a protruding portion having a large height; and an outer peripheral surface provided around the protruding portion at a position lower than the protruding portion by a preset height. A thermally sprayed film having a thickness equivalent to a height difference between the protruding portion and the outer peripheral surface is deposited on the outer peripheral surface such that the thermally sprayed film becomes continuous with the protruding portion. The electrostatic chuck is formed by installing an electrode between insulating members, and the electrostatic chuck is fixed to the base by using an adhesive to cover a boundary between a top surface of the protruding portion and a surface of the thermally sprayed film.