Plasma Etching Magnetic Ring X Point for Edge Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Plasma processing technologies face challenges in achieving accurate, precise, and uniform patterning of features at atomic scale dimensions with high repeatability and uniformity, particularly at the edge of substrates, due to non-uniform distribution of plasma species.
Innovation Solution
The use of an additional magnetic field generated by a set of magnets, including a ring X point, to modify plasma parameters and enhance local plasma density near the edge of the substrate, improving uniformity and etch rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional plasma processing is used, then plasma can be generated for etching, but plasma species distribution is non-uniform particularly at substrate edges
Solution Approach 1:
The patent applies a magnetic field configuration that creates different plasma conditions in different regions of the substrate. Specifically, magnetic rings are positioned to create enhanced magnetic field regions near substrate edges, which locally increases plasma species density and ionization in those areas, compensating for the natural edge effects that cause non-uniformity.
Solution Approach 2:
The patent changes the magnetic field parameters by introducing external magnetic rings with specific field strengths and positions. This modifies the plasma parameters (electron temperature, ion density, radical concentration) in a controlled manner, particularly enhancing these parameters near substrate edges to achieve more uniform plasma distribution across the entire substrate surface.
2Productivity
If feature size is shrunk to increase packing density, then component density increases, but patterning precision and profile control become more difficult
Solution Approach 1:
The magnetic field configuration creates locally optimized plasma conditions that provide better ion directionality and energy control. This enables precise etching of smaller features by controlling the ion flux and energy distribution, allowing accurate patterning even at reduced feature sizes while maintaining profile control.
Solution Approach 2:
The patent replaces conventional mechanical or purely electromagnetic field control with a magnetic field-based plasma control mechanism. The magnetic rings create localized magnetic confinement that directs plasma species flow and enhances ionization, providing better control over the etching process at sub-10nm dimensions where traditional methods struggle.
3Reliability
If additional magnetic field components are added to improve plasma uniformity, then plasma distribution improves, but system complexity increases
Solution Approach 1:
The magnetic rings serve multiple functions: they generate the magnetic field for plasma confinement, define the spatial distribution of plasma species, and can be adjusted to optimize different etching conditions. This multi-functionality reduces the need for separate components for each function, thereby limiting the increase in system complexity despite the addition of magnetic field control.
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
Enhances plasma uniformity and etch rate across the substrate, particularly at the edge, by locally adjusting plasma density through the ring X point, leading to improved etch performance and uniformity.
Implementation Method 1
a RF power source configured to generate a plasma in the plasma processing chamber
Implementation Method 2
a first magnet disposed above the substrate holder, the first magnet configured to apply an azimuthally symmetric magnetic field in the plasma processing chamber
Implementation Method 3
a second magnet disposed below the substrate holder, the second magnet configured to modify the azimuthally symmetric magnetic field and create a ring X point where the azimuthally symmetric magnetic field is locally neutralized
Data Source
AI summary
A plasma etching system that includes a plasma processing chamber, a substrate holder disposed in the plasma processing chamber, a RF power source configured to generate a plasma in the plasma processing chamber, a first magnet disposed above the substrate holder, the first magnet configured to apply, in the plasma processing chamber, an azimuthally symmetric magnetic field that is independent from a magnetic field generated by the RF power source, and a second magnet disposed below the substrate holder and configured to modify the azimuthally symmetric magnetic field and create a ring X point between the first magnet and the second magnet, where positions of the first magnet and the second magnet are arranged such that the ring X point is located nearer to an edge of the substrate holder than a center of the substrate holder.