Curved Surface Process Kit for Plasma Chamber Contamination Control
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Solution Overview
Problem
Plasma processing chambers face challenges with the buildup of contaminants on surfaces of the process kit, which can become particle sources and affect chip yield, due to the deposition of etched materials during the plasma cleaning or etching process.
Innovation Solution
A process kit for plasma processing chambers is designed with a gas diffuser and shields featuring curved surfaces and annular gaps to efficiently direct contaminants and substrate materials away from surfaces, reducing deposition and maintaining chamber cleanliness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a process kit with liners is used to define process region boundaries, then plasma containment is improved, but contaminant deposition on chamber surfaces increases
Solution Approach 1:
The patent applies curved surfaces throughout the process kit components. The upper shield includes a curved top surface and a curved cylindrical liner, while the lower shield features a curved horizontal surface and a curved vertical liner. These curved surfaces guide plasma and contaminants away from corner locations, reducing deposition while maintaining effective plasma containment within the process region.
2Reliability
If liners with tortuous flow paths are used, then plasma is trapped effectively, but displaced materials are deposited on walls
Solution Approach 1:
The curved surfaces in the liners create smooth flow paths that redirect contaminants away from wall surfaces. The upper shield's curved cylindrical liner and the lower shield's curved vertical and horizontal liners work together to guide displaced materials through the process region without causing deposition on the liner walls, while still maintaining effective plasma trapping.
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 enhances plasma processing efficiency by minimizing contaminant buildup on surfaces, ensuring fewer maintenance requirements and improved chip yield by facilitating the smooth flow and removal of contaminants and substrate materials.
Implementation Method 1
Electromagnetic energy (e.g., radio frequency) is applied to the injected gas to excite the gas into a plasma state
Implementation Method 2
The plasma releases ions that bombard the surface of the substrate to remove contaminants and/or material from the substrate
Implementation Method 3
a pump removes most of the air from the chamber
Implementation Method 4
A center of the circular interior top surface includes a circular aperture... A first portion extends radially outward from the aperture in which a distance from the interior top surface to the plane increases as the distance from the aperture increases
Data Source
AI summary
Apparatus for plasma processing of semiconductor substrates. Aspects of the apparatus include an upper shield with a gas diffuser arranged at a center of the upper shield. The gas diffuser and upper shield admit a process gas to a processing chamber in a laminar manner. A profile of the upper shield promotes radial expansion of the process gas and radial travel of materials etched from a surface of the substrates. Curvatures of the upper shield direct the etched materials to a lower shield with reduced depositing of etched materials on the upper shield. The lower shield also includes curved surfaces that direct the etched materials toward slots that enable the etched materials to exit from the process chamber with reduced depositing on the lower shield.