Focus Ring Inner Profile for Precise Electrostatic Chuck Alignment
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Solution Overview
Problem
Existing semiconductor fabrication methods face challenges in aligning the focus ring with the electrostatic chuck structure, leading to deviations in substrate processing and plasma distribution, which affect the uniformity and accuracy of semiconductor device fabrication.
Innovation Solution
A focus ring design with a central axis aligned to improve substrate alignment, featuring a top surface with a smaller inner diameter and a bottom surface with a larger inner diameter, and inner lateral surfaces that make different angles with the central axis, allowing for precise alignment with the electrostatic chuck structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional focus ring with uniform inner diameter is used, then the structure is simple and easy to manufacture, but the alignment with the electrostatic chuck structure is inaccurate, causing substrate processing deviations
Solution Approach 1:
The focus ring employs an asymmetric structure where the inner lateral surface is divided into a first inner lateral surface and a second inner lateral surface with different angles relative to the central axis. The first inner lateral surface has a first angle, while the second inner lateral surface has a second angle that differs from the first angle. This asymmetric configuration enables precise alignment with the electrostatic chuck structure, resolving the alignment accuracy issue while maintaining reasonable structural complexity.
Solution Approach 2:
Different portions of the focus ring's inner lateral surface are given different geometric properties. The first inner lateral surface and second inner lateral surface have distinct angles, creating local variations in the structure that correspond to different alignment requirements at different positions. This local differentiation allows the focus ring to achieve accurate alignment with the electrostatic chuck structure.
2Manufacturing precision
If the focus ring is not precisely aligned with the electrostatic chuck structure, then the fabrication process is simpler, but plasma distribution becomes non-uniform and substrate properties show deviations
Solution Approach 1:
The asymmetric inner lateral surface configuration, with the first and second inner lateral surfaces having different angles, creates a geometric alignment mechanism that ensures the focus ring's central axis aligns with the electrostatic chuck structure's central axis. This alignment ensures uniform plasma distribution during semiconductor fabrication processes.
3Manufacturing precision
If the inner lateral surface has a single angle design, then the focus ring structure is simpler, but the alignment flexibility and precision with the electrostatic chuck structure are reduced
Solution Approach 1:
The inner lateral surface is designed with asymmetric angles: the first inner lateral surface forms a first angle with the central axis, while the second inner lateral surface forms a second angle that is different from the first angle. This asymmetric geometric design provides both alignment precision and flexibility in matching the electrostatic chuck structure's geometry.
Solution Approach 2:
Different angular properties are assigned to different sections of the inner lateral surface. The first inner lateral surface and second inner lateral surface have locally optimized angles that correspond to the specific alignment requirements of the electrostatic chuck structure, enhancing overall alignment precision.
Data Source
AI summary
A substrate processing apparatus includes a focus ring, the focus ring includes a central axis that extends in a first direction, a top surface having a first inner diameter, a bottom surface having a second inner diameter that is smaller than the first inner diameter, and an inner lateral surface between the top surface and the bottom surface, the inner lateral surface including a first inner lateral surface and a second inner lateral surface, where the second inner lateral surface extends downward from the first inner lateral surface and a first angle between the first inner lateral surface and a line corresponding to the first direction is different from a second angle between the second inner lateral surface and the line corresponding to the first direction.