RF Blocker Layout for Plasma Density Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Plasma density within a plasma chamber becomes non-uniform, particularly at higher pressures, leading to issues in semiconductor processing such as sidewall doping for CMOS image sensors and reducing contact resistance for memory devices.
Innovation Solution
Incorporation of RF blockers adjacent to the dielectric window in the plasma chamber to selectively block RF energy, using multiple blockers with varying alignments and openings to adjust plasma density uniformly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If higher pressure is used in the plasma chamber, then beneficial applications such as sidewall doping and reducing contact resistance are achieved, but plasma density uniformity deteriorates
Solution Approach 1:
The patent applies local quality by positioning RF blockers at specific locations within the plasma chamber where non-uniformity occurs. The blockers are strategically placed to target high-density regions and reduce plasma density locally, thereby achieving uniform plasma distribution across the chamber while maintaining the benefits of higher pressure operation.
Solution Approach 2:
The RF blockers serve as intermediary elements between the RF antenna and the plasma. These blockers selectively absorb or reflect RF energy in specific regions, acting as mediators to control plasma density distribution. By introducing these intermediary components, the system achieves uniform plasma density while operating at higher pressures for improved processing performance.
2Manufacturing precision
If RF blockers are added to control plasma density, then plasma uniformity is improved, but device complexity increases
Solution Approach 1:
The RF blocking function is segmented into multiple discrete blockers positioned at different locations within the plasma chamber. Each blocker addresses specific regional non-uniformity, allowing for modular adjustment and optimization. This segmentation approach enables precise control of plasma density while maintaining flexibility in system design and configuration.
Solution Approach 2:
The patent utilizes parameter changes by varying the material properties, dimensions, and positions of the RF blockers to optimize plasma uniformity. By adjusting parameters such as blocker thickness, material composition, and spatial arrangement, the system achieves effective plasma density control without requiring complex additional components or systems.
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
Improves plasma density uniformity by reducing density in high-density regions, enhancing processing consistency and compatibility with existing semiconductor equipment.
Implementation Method 1
An antenna is used to generate RF energy that is inductively coupled into the plasma chamber
Implementation Method 2
an RF blocker disposed adjacent to the dielectric window to block a portion of the RF energy
Data Source
AI summary
A semiconductor processing system with improved plasma density is disclosed. The system includes a plasma chamber having a base, chamber walls and a top wall. An antenna is used to generate RF energy that is inductively coupled into the plasma chamber. The antenna comprises a plurality of coils that are proximate a dielectric window. One or more RF blockers are disposed adjacent to the dielectric window to block some of the RF energy from entering the plasma chamber. If the RF blocker is placed near a region of high plasma density, the density in that region may be reduced, improving the uniformity of the plasma density within the plasma chamber. Further, the RF blockers may have openings and may also be overlapped to create varying degrees of blocking.