Atomic Layer Etching Using Remote Plasma Segmentation
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Solution Overview
Problem
Conventional etching processes face challenges in selectively removing materials from semiconductor substrates, particularly in confined trenches and maintaining structural integrity, due to issues like deformation and substrate damage from plasma etching.
Innovation Solution
The technology involves forming a remote plasma of an inert precursor in a processing chamber, maintaining it throughout the process, and adding an etchant precursor to produce plasma effluents that selectively remove modified material surfaces from the substrate, while controlling pressure and frequency to minimize damage and byproduct flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If local plasma is used for etching, then trench penetration and structural integrity are improved, but substrate damage from electric arcs increases
Solution Approach 1:
The plasma source is segmented into two distinct regions: a remote plasma generation region separated from the substrate processing region by a showerhead. This segmentation allows plasma to be generated remotely without direct contact with the substrate, eliminating arc damage while maintaining etching capability through controlled plasma effluents.
Solution Approach 2:
A showerhead acts as an intermediary component between the plasma source and substrate. It distributes plasma effluents uniformly across the processing region while preventing direct plasma-substrate contact that would cause arc damage, thus mediating between plasma generation and substrate processing.
2Productivity
If plasma power is increased to improve etching rate, then productivity is improved, but substrate damage and byproduct deposition increase
Solution Approach 1:
The harmful byproducts are extracted and removed from the processing region through controlled plasma effluent flow. The remote plasma configuration allows byproducts to be carried away by the flowing effluents before they can deposit on the substrate, enabling higher power operation without increased deposition.
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 reduces plasma-induced damage, maintains structural integrity, and enhances etching selectivity, reducing processing time and byproduct deposition, thereby improving the quality and efficiency of semiconductor processing.
Implementation Method 1
forming a remote plasma of an inert precursor in a remote plasma region of a processing chamber
Implementation Method 2
The remote plasma may include a capacitively-coupled plasma
Implementation Method 3
forming a bias plasma of the inert precursor within a processing region of the processing chamber
Implementation Method 4
adding an etchant precursor to the remote plasma region to produce etchant plasma effluents
Implementation Method 5
Chemical etching is used for a variety of purposes including transferring a pattern in photoresist into underlying layers
Data Source
AI summary
Processing methods may be performed to remove unwanted materials from a substrate. The methods may include forming a remote plasma of an inert precursor in a remote plasma region of a processing chamber. The methods may include forming a bias plasma of the inert precursor within a processing region of the processing chamber. The methods may include modifying a surface of an exposed material on a semiconductor substrate within the processing region of the processing chamber with plasma effluents of the inert precursor. The methods may include extinguishing the bias plasma while maintaining the remote plasma. The methods may include adding an etchant precursor to the remote plasma region to produce etchant plasma effluents. The methods may include flowing the etchant plasma effluents to the processing region of the processing chamber. The methods may also include removing the modified surface of the exposed material from the semiconductor substrate.