Scanning Probe Microscope - Seiko, SPA-400 안동대학교 공동실험실습관 유상훈

Contents 기기구조 및 원리 Apparatus Application

SPA-400 구조

Main Body of SPM Front open space Magnetic fixed sample holder

Invention of SPM STM was invented by Binnig & Rohrer in 1981 - only for conducting material - need high vacuum, ultra-cryo system Invention of AFM at Stanford Univ. in 1985 - non-conductors as well as semi-conductor, insulator

Micro-Surface Analytic Tools SEM(natural and FE-SEM) - popular tool for analyzing surface, cross-section - need sample preparation for non-conductors TEM - high resolution for microstructure - very hard to prepare ultra-thin specimen SPM - direct measurement - easy to handle samples - high resolution and 3D image - various applications(electric, magnetic..)

Advantage over SEM and TEM Quantitative 3D Information High Resolution: X-Y: 0.2nm, Z: 0.01nm Easy Sample Preparation (non-conductor) Various Operating Condition-vac., even in air, liquid Various Measuring Modes-Electric, Magnetic, Physical Atomic Scale Manipulation-Nanolithography

SPM Imaging Modes STM(Scanning Tunneling Microscope) - Electronic Structure AFM(Atomic Force Microscope) -Topography DFM(Dynamic Force Microscope ) - Topography KFM(Kelvin Force Microscope) - Surface Potential, Charge MFM(Magnetic Force Microscope) - Magnetic Field FFM, LFM(Friction Force Microscope) – Surface Friction VE-AFM(Visco-Elastic AFM) – Hardness, Viscosity

Specification of SPA-400 Resolution : X-Y: 0.2nm, Y: 0.01nm Scan Range : 20㎛, 100㎛ Sample Stage : 150mm Optical Microscope : X 1,000

Atomic Interaction Force

Scanning Modes/Inter-atomic Force

Schematic Diagram of AFM

Optics for contact, NC, tapping-AFM

Cantilevers (SPM Probes) Silicon Nitride exhibit excellent flexibility Contact AFM tip Silicon crystal high frequency oscillating(100kHz) more stiffer than Si3N4 NC AFM tip

Carbon Nano Tube Probe High durability - CNT is made of carbon and has high elasticity Less contamination - Chemically inactive graphite structure - hydrophobic characteristics - hard to be contaminated

Cantilever Holders

X, Y, Z - Scanners

Liquid Holder and Cell

SPM Scanning Modes Contact Mode(AFM) Tapping Mode(DFM) Provide atomic resolution in air Destructive method for soft sample Tapping Mode(DFM) Non-Contact Mode(DFM) <Non-Contact Mode> <Intermittent Mode> Nondestructive method for soft sample Suitable mode for the rough and sticky surface

Atomic Resolution(STM & AFM) Atomic Step ( Si, AFM, in air) STM image of Si

Principle of DFM Q-curve - Cantilever를 공진시켜 시료표면과의 인력, 척력을 검출하여 표면형상 측정 Q-curve

DFM in Liquid DFM in liquid is controlled by the high degree resonance of the cantilever

Application of DFM to Biology Plasmid DNA

Image of MFM – Hard Disk Topography MFM image Topography MFM image <스캔 영역 90㎛> <스캔 영역 10㎛>

Potential difference between the natural oxide and field oxide Image of KFM-thin metal film - 시료와 탐침간에 작용하는 정전기력 이용, 시료의 표면전위 측정 Natural oxide : 970mV Field enhanced oxidation: 960mV Topography（3.5 μm x 3.5 μm ） Electrical Potential （3.5 μm x 3.5 μm ) Potential difference between the natural oxide and field oxide

Nanolithography with SPM Si wafer (before modification) SiO2 on Si pattern(after modification)