Accelerated Neutral Beam for Reduced Surface Mixing
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Solution Overview
Problem
Conventional ion beams used for surface etching in analytical instruments penetrate deeply, causing knock-on effects and forming thick amorphous layers that distort depth measurements, and may damage insulating materials due to charging issues.
Innovation Solution
The use of an accelerated Neutral Beam derived from a gas cluster ion beam (GCIB), which is partially or fully dissociated to produce a beam of neutral gas clusters or monomers, reducing surface mixing and avoiding charge-induced damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional ion beams are used for surface etching, then etching capability is achieved, but the beam penetrates deeply causing knock-on effects and forms thick amorphous layers that distort depth measurements
Solution Approach 1:
The invention changes the fundamental parameters of the etching beam by using gas cluster ions (hundreds to thousands of atoms/molecules bound together) instead of conventional single atoms or small molecules. This parameter change in beam composition reduces the knock-on effect and minimizes amorphous layer formation, thereby improving depth measurement accuracy while maintaining etching capability
Solution Approach 2:
The gas cluster ion acts as an intermediary between the conventional ion beam and the surface being etched. The cluster structure distributes the momentum transfer over multiple atoms, reducing the harmful knock-on effects on individual surface atoms while still achieving effective etching through collective interaction
2Productivity
If ion beams are used for etching, then etching process is effective, but charge-induced damage occurs on insulating materials due to accumulated charges
Solution Approach 1:
The invention changes the charge-to-mass ratio parameter by using gas cluster ions which have much lower charge per unit mass compared to conventional ion beams. This parameter change allows effective etching while reducing the accumulation of harmful charges on insulating material surfaces
Solution Approach 2:
The gas cluster ion beam provides localized energy deposition at the surface through the cluster structure, concentrating the etching effect where needed while distributing the charge load over a larger mass, thereby reducing charge-induced damage on insulating materials
3Productivity
If high current intensity ion beams are used, then etching speed increases, but space charge-induced defocusing occurs that inhibits beam transport over long distances
Solution Approach 1:
The invention changes the space charge density parameter by using gas cluster ions with lower charge per unit mass. This allows higher current intensities to be transported over long distances without significant space charge defocusing, enabling both fast etching and long beam transport
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 results in a thinner disrupted layer with improved depth resolution and allows for safe processing of insulating materials by minimizing atomic depth mixing and charging effects.
Implementation Method 1
Ions have long been favored for use in many processes because their electric charge facilitates their manipulation by electrostatic and magnetic fields
Implementation Method 2
GCIB has a distinct advantage over conventional ion beams in that a gas cluster ion with a single or small multiple charge enables the transport and control of a much larger mass-flow
Implementation Method 3
The use of an accelerated Neutral Beam provides a physical etching method that results in a thinner layer of material mixing at the etched surface
Data Source
AI summary
Apparatus and methods are disclosed for employing an accelerated neutral beam derived from an accelerated gas cluster ion beam as a physical etching beam for providing reduced material mixing at the etched surface, compared to previous techniques. This results in the ability to achieve improved depth profile resolution in measurements by analytical instruments such as SIMS and XPS (or ESCA) analytical instruments.