Low Profile Process Kit Lip Geometry for Semiconductor Substrate Protection
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Solution Overview
Problem
Existing substrate support process kits in semiconductor fabrication are prone to contamination and require frequent cleaning due to deposited materials, which can damage the substrate and chamber, and exposed metal surfaces can lead to arcing and contamination during plasma processes.
Innovation Solution
A process kit with an annular body having an inner and outer edge, an upper and lower surface, and inner and outer lips that conform to the substrate support pedestal, designed to reduce contamination and facilitate efficient cleaning by minimizing exposed surfaces and optimizing gas flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a process kit is disposed atop and/or around the substrate support to prevent damage and contamination, then the substrate support is protected from damage and metal contamination, but contaminants deposited on the process kit proximate the wafer edge may still contaminate the wafer being processed
Solution Approach 1:
The process kit transitions from a traditional flat, two-dimensional configuration to a three-dimensional structure with vertical lips extending upward from the annular body. The inner lip rises vertically from the upper surface near the inner edge, and the outer lip extends downward from the lower surface near the outer edge to conform to the substrate support pedestal. This dimensional transformation creates a more comprehensive barrier that protects the substrate support while minimizing contamination risk to the wafer.
2Reliability
If a process kit is used to protect the substrate support, then damage and contamination are prevented, but materials sputtered off of the substrate proximate the substrate edge may be deposited upon the process kit near the substrate edge, thereby increasing the buildup of materials on the process kit and shortening the mean time between cleaning
Solution Approach 1:
The process kit employs specific geometric parameters including a downwardly inclined upper surface angled between 5-65 degrees from the inner edge toward the outer edge, and vertically extending lips with specific heights (inner lip at least 0.1 inches). These parameter optimizations are designed to minimize material deposition on the process kit by directing sputtered materials away from horizontal surfaces, thereby reducing the frequency of cleaning required while maintaining protective functionality.
3Reliability
If the process kit has a conventional design with horizontal surfaces, then it provides basic protection, but the exposed surfaces increase the area for contaminant deposition and require more frequent cleaning
Solution Approach 1:
The process kit applies different surface orientations and geometries to different regions to optimize performance. The upper surface is inclined at 5-65 degrees to reduce material accumulation, while the inner lip extends vertically upward and the outer lip extends downward to conform to the pedestal. This localized variation in surface quality provides enhanced protection and reduced contamination without requiring complete structural redesign.
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 process kit effectively reduces contamination of the substrate and shortens the time between cleanings by minimizing deposition on the kit and allowing for faster heating and removal of contaminants during cleaning processes.
Implementation Method 1
an inner lip disposed proximate the inner edge and extending vertically from the upper surface at least about 0.1 inches
Implementation Method 2
designed to reduce contamination and facilitate efficient cleaning by minimizing exposed surfaces
Implementation Method 3
allowing for faster heating and removal of contaminants during cleaning processes
Implementation Method 4
exposed metal surfaces of the substrate support may lead to arcing in the plasma process and metal contamination of the substrate and/or the chamber
Data Source
AI summary
Embodiments of process kits for substrate supports of semiconductor substrate process chambers are provided herein. In some embodiments, a process kit for a semiconductor process chamber may include an annular body being substantially horizontal and having an inner and an outer edge, and an upper and a lower surface; an inner lip disposed proximate the inner edge and extending vertically from the upper surface; and an outer lip disposed proximate the outer edge and on the lower surface, and having a shape conforming to a surface of the substrate support pedestal. In some embodiments, a process kit for a semiconductor process chamber my include an annular body having an inner and an outer edge, and having an upper and lower surface, the upper surface disposed at a downward angle of between about 5-65 degrees in an radially outward direction from the inner edge toward the outer edge.