Switchable Ion Gun for Surface Processing
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Solution Overview
Problem
Existing ion guns face challenges in producing low-energy argon ion beams for surface etching without damaging organic materials, and previous solutions like carbon-based ion beams lead to surface deposition and erroneous results, while metal cluster ion beams are difficult to form and require large vacuum systems.
Innovation Solution
A switchable ion gun capable of operating in both cluster and atomic modes, allowing for the production of ion beams with adjustable energy per atom, enabling gentle etching of organic surfaces and aggressive cleaning of inorganic surfaces using a single device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If low energy argon ion beams are used to etch organic surfaces, then sample damage is avoided, but etching efficiency is insufficient
Solution Approach 1:
The invention segments the ion beam into clusters of multiple atoms (e.g., Ar3+, Ar5+, etc.) instead of using single argon atoms. Each cluster acts as a separate etching unit that delivers multiple atoms to the surface simultaneously, thereby maintaining low per-atom energy to avoid damage while achieving effective etching through collective action of the cluster
Solution Approach 2:
The invention changes the parameter of ion beam composition from monatomic to polyatomic clusters. By controlling the cluster size distribution and selecting specific cluster masses, the system achieves optimal balance between gentle etching (low per-atom energy) and etching efficiency (multiple atoms per incident particle)
2Productivity
If carbon-based ion beams are used for surface etching, then etching capability is improved, but surface deposition occurs leading to erroneous results
Solution Approach 1:
The invention uses inert argon gas clusters instead of carbon-based ions. Argon is chemically inert and does not deposit on the surface during etching, thereby maintaining analysis accuracy while providing sufficient etching capability through physical sputtering by the cluster ions
3Object-affected harmful factors
If metal cluster ion beams are used for surface processing, then sample damage is avoided, but device complexity and vacuum system requirements increase
Solution Approach 1:
The invention uses simple, readily available argon gas that can be easily introduced and removed from the system. The argon clusters are generated in-situ from gas phase, eliminating the need for complex metal cluster source apparatus. The gas can be quickly pumped away, simplifying the vacuum system requirements compared to metal cluster sources
4Adaptability or versatility
If a single ion gun is used for both soft and hard materials, then device versatility is improved, but beam energy control complexity increases
Solution Approach 1:
The invention introduces dynamic control of cluster mass selection and energy distribution. By varying the acceleration voltage and cluster selection parameters, the same ion gun can adaptively adjust its beam characteristics to suit different material types (soft organic materials requiring gentle etching vs. hard inorganic materials requiring aggressive cleaning), thereby achieving versatility without requiring multiple fixed-purpose ion guns
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
The dual-mode ion gun allows for effective depth profiling of both soft and hard materials, reducing the need for multiple ion guns and vacuum systems, while maintaining sample chemistry integrity and improving etching efficiency.
Implementation Method 1
clusters of a few hundred argon atoms to a few tens of thousands of argon atoms can readily be formed. This has been widely used in SIMS and has been proposed for XPS in JP 08-122283 A, JP 2008-116363 A and WO 2009/131022
Implementation Method 2
an ion beam source which ionises the clusters and/or atoms to form an ion beam
Implementation Method 3
a variable mass selector to mass-select the ionised clusters and/or atoms to produce a focused ion beam
Data Source
AI summary
A method of processing one or more surfaces is provided, comprising: providing a switchable ion gun which is switchable between a cluster mode setting for producing an ion beam substantially comprising ionized gas clusters for irradiating a surface and an atomic mode setting for producing an ion beam substantially comprising ionized gas atoms for irradiating a surface; and selectively operating the ion gun in the cluster mode by mass selecting ionized gas clusters using a variable mass selector thereby irradiating a surface substantially with ionized gas clusters or the atomic mode by mass selecting ionized gas atoms using a variable mass selector thereby irradiating a surface substantially with ionized gas atoms. Also provided is a switchable ion gun comprising: a gas expansion nozzle for producing gas clusters; an ionization chamber for ionizing the gas clusters and gas atoms; and a variable (preferably a magnetic sector) mass selector for mass selecting the ionized gas clusters and ionized gas atoms to produce an ion beam variable between substantially comprising ionized gas clusters and substantially comprising ionized gas atoms. Preferably, the gun comprises an electrically floating flight tube for adjusting the energy of the ions while within the mass selector.