Ion Scattering Surface Analysis for Fast Surface Potential Mapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current Kelvin Probe Force Microscopy (KPFM) techniques face challenges such as low throughput due to slow scanning speeds, potential distortion from thermal expansion, interference from optically active samples, complex and costly apparatus configurations, and limited ability to measure properties beyond surface potential and work function.
Innovation Solution
A surface analysis method and apparatus utilizing ion irradiation with a specific ion species at a preset kinetic energy and incident angle, followed by observation of scattered ions for charge transfer reactions, allowing for the calculation of electrical and physical properties like surface potential, double ionization energy, and spin state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If KPFM is used to measure surface potential distribution, then non-destructive measurement is achieved, but measurement time becomes excessively long due to the need to repeatedly search for cancellation voltage at each position
Solution Approach 1:
The patent replaces the mechanical feedback system of KPFM (which requires iterative voltage adjustment and feedback control) with a direct ion scattering measurement system. By using ion beams to probe the surface and measuring scattered ion energies, the system obtains surface potential information without the need for feedback loops or iterative searches, dramatically reducing measurement time while maintaining non-destructive measurement capabilities.
2Loss of information
If KPFM is used to obtain surface potential distribution, then electrical property information is obtained, but apparatus configuration becomes complicated and expensive due to requirement of feedback circuits
Solution Approach 1:
The patent extracts the essential measurement function from the complex KPFM system by removing the feedback circuitry and iterative control mechanisms. The core function of obtaining surface potential information is retained through direct ion scattering measurements, where the surface potential affects ion scattering energy, which is then detected and analyzed to retrieve surface potential distribution without requiring complex feedback systems.
3Measurement precision
If laser light is used to detect probe displacement in KPFM, then minute displacement detection is achieved, but measurement is affected when sample is optically active
Solution Approach 1:
The patent substitutes the optical detection method (laser light) with an ion-based detection method. Instead of using laser light to detect probe displacement, the system uses ion beams to probe the surface and measures the energy of scattered ions. This eliminates optical interference issues while maintaining high measurement precision, as ion scattering energy is directly influenced by surface potential without being affected by the sample's optical properties.
4Loss of information
If KPFM is used to measure surface potential, then electrical property measurement is achieved, but throughput decreases due to slow scanning speed requirements
Solution Approach 1:
The patent implements continuous measurement capability by using ion scattering that can be performed at higher scanning speeds. The ion beam continuously probes the surface while the sample or beam is scanned, and scattered ion energies are continuously detected and analyzed. This continuous measurement approach eliminates the need for slow iterative voltage searches at each position, thereby maintaining surface potential distribution information while significantly improving measurement throughput.
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 eliminates the need for contact potential cancellation, significantly reduces measurement time, improves throughput, and enables the acquisition of additional surface properties like double ionization energy and spin state, providing more comprehensive information without thermal distortion or optical interference.
Implementation Method 1
an observation step of observing scattered ions that originate from the ion stream and have undergone a charge transfer reaction with an atom or molecule present on the surface of the solid sample
Data Source
AI summary
A surface analysis apparatus includes: an ion irradiation unit configured to irradiate a surface of a solid sample with an ion stream of a specific ion species having a preset value of kinetic energy at a predetermined incident angle; an observation unit configured to observe scattered ions that originate from the ion stream and have undergone a charge transfer reaction with an atom or molecule present on a surface of the solid sample; and an information calculation unit configured to obtain information on electrical properties or physical properties on a surface of the solid sample on the basis of an observation result of the scattered ions in the observation unit. As a result, it is possible to efficiently acquire, in a short time, the distribution of the information on the electrical properties or physical properties such as the surface potential of the solid sample.