Resonant Focus Ring for Plasma Edge Uniformity Control
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Solution Overview
Problem
Conventional plasma processing apparatuses and methods struggle to adequately control plasma processing parameters at the edge region of a substrate relative to the central region, leading to non-uniform processing conditions and decreased device yield due to defects in the edge region, which is exacerbated by the material and electrical discontinuities at the substrate edge.
Innovation Solution
The apparatus includes a conductive structure, such as a resonant structure, embedded in a focus ring or pedestal to generate a localized plasma at the edge region, using high-frequency power to control process conditions without altering the central region, thereby facilitating independent control of species flux.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional plasma processing is used without edge-specific control, then the central region achieves uniform processing conditions, but the edge region suffers from non-uniform conditions due to material and electrical discontinuities
Solution Approach 1:
The plasma processing system is segmented into two independent control zones: a central region controlled by the main plasma source and an edge region controlled by a separate resonant structure. This segmentation allows independent optimization of processing conditions in each region, resolving the contradiction between central region uniformity and edge region controllability.
Solution Approach 2:
The resonant structure provides localized plasma generation specifically at the edge region, creating different plasma characteristics (higher radical flux, lower ion flux) only where needed. This local quality enhancement allows edge region processing uniformity without altering the desirable conditions in the central region.
2Manufacturing precision
If attempts are made to correct variations above the edge region, then edge processing conditions improve, but desirable conditions above the central region are altered
Solution Approach 1:
The system separates edge region plasma control from central region plasma generation by using a dedicated resonant structure for the edge. This segmentation enables independent adjustment of edge region parameters (radical and ion flux) without affecting the central region processing conditions, thus maintaining both edge uniformity and central region productivity.
Solution Approach 2:
The resonant structure acts as an intermediary device that introduces localized plasma generation at the edge region. This intermediary approach allows correction of edge region variations through controlled radical and ion flux from the resonant structure, while the main plasma source continues to provide optimal conditions for the central region.
3Manufacturing precision
If global plasma parameters are adjusted to improve edge region processing, then edge uniformity improves, but overall processing precision decreases due to loss of control in the central region
Solution Approach 1:
The plasma processing system is divided into independent control zones with the resonant structure providing localized species flux control at the edge region. This segmentation enables precise measurement and control of radical and ion flux separately in the edge region without disrupting the species flux balance in the central region, maintaining overall processing precision.
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
This approach allows for precise control of plasma processing conditions at the edge region, improving yield by reducing defects and maintaining uniformity across the substrate without requiring costly modifications to existing apparatuses.
Implementation Method 1
a resonant structure disposed at the pedestal. The resonant structure is configured to generate a plasma localized at an edge region of the substrate
Implementation Method 2
The resonant structure is configured to generate a plasma localized at an edge region of the substrate
Implementation Method 3
The conductive structure is configured to generate a plasma localized along the annular shape and surrounding the interior opening
Data Source
AI summary
A focus ring includes an insulating material having an annular shape that defines an interior opening. The focus ring further includes a conductive structure embedded within the insulating material. The conductive structure is configured to generate a plasma localized along the annular shape and surrounding the interior opening. The conductive structure may be configured to generate the plasma using alternating current power indirectly coupled to the conductive structure through the insulating material. The conductive structure may include a capacitive structure and an inductive structure, which may both be fully encased in the insulating material. The capacitive structure and the inductive structure may together form a resonant inductor-capacitor circuit comprising a resonant frequency greater than 30 MHz.