Edge Ring Contact Structure for Uniform Plasma Etching
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Solution Overview
Problem
The wear of edge rings in processing chambers during plasma processing leads to uneven etching rates and tilting of etching profiles due to changes in the sheath thickness and ion incidence angle, necessitating frequent replacements and impacting productivity.
Innovation Solution
A placement apparatus with a stage, edge ring, conductive connecting member, and contacting members that ensure stable contact between the edge ring and the stage, allowing precise control of the edge ring's electric potential and sheath thickness through DC voltage application, thereby maintaining uniform etching profiles and extending the edge ring replacement cycle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the edge ring is replaced frequently to maintain etching uniformity, then the etching profile quality is improved, but the productivity deteriorates due to replacement time loss
Solution Approach 1:
The edge ring is designed to automatically maintain stable contact with the stage through elastic deformation of the contacting member, enabling self-adjustment without external intervention. This self-service mechanism ensures consistent electric potential and sheath thickness, maintaining etching uniformity while reducing replacement frequency
Solution Approach 2:
The patent changes the physical state of the contacting member from rigid to elastic, allowing it to deform and maintain stable contact. This parameter change enables the edge ring to self-adjust its position and electrical contact, resolving the contradiction between maintaining precision and improving productivity
2Manufacturing precision
If DC voltage is applied to the edge ring to control sheath thickness, then the etching rate distribution is improved, but the contact stability between edge ring and stage becomes critical
Solution Approach 1:
The contacting member is designed as an elastic component that can deform to maintain stable contact between the edge ring and stage. This flexibility ensures reliable electrical contact for DC voltage application while accommodating minor position variations, thus maintaining both etching precision and contact reliability
Solution Approach 2:
The elastic contacting member ensures stable electrical contact between the edge ring and stage, maintaining equipotential conditions. This stable electrical connection is essential for precise DC voltage control, which in turn enables accurate sheath thickness control and uniform etching rate distribution
3Measurement precision
If the edge ring is made to contact the stage stably to control electric potential, then the sheath thickness control precision is improved, but the device complexity increases
Solution Approach 1:
The elastic contacting member provides self-adjusting contact between the edge ring and stage, automatically maintaining stable electrical connection without requiring external control systems or complex adjustment mechanisms. This self-service approach achieves precise sheath thickness control while minimizing device complexity
Solution Approach 2:
The contacting member is designed as a simple elastic component that can be easily replaced if needed, rather than a complex adjustable mechanism. This approach achieves precise electrical contact control with minimal complexity, treating the contacting member as a consumable or easily replaceable component
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
The solution stabilizes the edge ring's contact with the stage, ensuring uniform etching rates and reducing the frequency of edge ring replacements, thus enhancing productivity by maintaining consistent plasma processing conditions.
Implementation Method 1
a conductive connecting member connected with the edge ring at the locking part; and a first contacting member configured to cause the edge ring to contact the stage
Implementation Method 2
When DC voltage is applied to an edge ring, it is important that the edge ring is stably in contact with a base member of a stage on which the edge ring is placed. By the edge ring being in contact with the base member stably, electric potential of the edge ring becomes equal to electric potential of the base member, and a thickness of a sheath on the edge ring can be controlled precisely
Data Source
AI summary
A placement apparatus for placing a workpiece is provided. The placement apparatus includes a stage on which a workpiece can be placed in a processing vessel; an edge ring including a locking part which is disposed on the stage so as to surround a periphery of the workpiece; a conductive connecting member connected with the edge ring at the locking part; and a first contacting member configured to cause the edge ring to contact the stage, while the edge ring is connected with the connecting member.