• Journal of Electrical Engineering and Technology
• /
• 제6권1호
• /
• pp.119-122
• /
• 2011

A new high speed AFM probe has been proposed and fabricated. The probe is integrated with PZT actuated cantilever realized in bulk silicon wafer using heavily boron doped silicon as an etch stop layer. The cantilever thickness can be accurately controlled by the boron diffusion process. Thick SCS cantilever and integrated PZT actuator make it possible to be operated at high speed for fast imaging. The resonant frequency of the fabricated probe is 92.9 kHz and the maximum deflection is 5.3 ${\mu}m$ at 3 V. The fabricated probe successfully measured the surface of standard sample in an AFM system at the scan speed of 600${\mu}m$/sec.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.552-555
• /
• 2004

The reliability issue of the probe tip/recording media interface is one of the most crucial concerns in the Atomic Force Microscope (AFM)-based recording technology. In this work, the tribological characteristics of the probe/media interface were investigated by performing wear tests using an AFM. The ranges of applied normal load and sliding velocity for the wear test were 10 to 50nN and 2 to 20$\mu$m/s respectively. The damage of the probe tip was quantitatively as well as qualitatively characterized by Field Emission Scanning Probe Microscope (FESEM) analysis and calculated based on Archard s wear equation. It was shown that the wear coefficient of the probe tip was in the order of 10$^{-4}$ ~ 10$^{-3}$ , and significant contamination at the end of the probe tip was observed. Thus in order to implement the AFM-based recording technology, tribological optimization of the probe/media interface must be achieved.

• Tribology and Lubricants
• /
• 제28권2호
• /
• pp.62-69
• /
• 2012

Atomic force microscopy (AFM) has been widely utilized as a versatile tool not only for imaging surfaces but also for understanding nano-scale interfacial phenomena. By measuring the responses of the photo detector due to bending and torsion of the cantilever, which are caused by the interactions between the probe and the sample surface, various interfacial phenomena and properties can be explored. One of the challenges faced by AFM researchers originates in the physics of measuring the small forces that act between the probe of a force sensing cantilever and the sample. To understand the interactions between the probe and the sample quantitatively, the force calibration is essential. In this work, the procedures used to calibrate AFM instrumentation for nano-scale force measurement in normal and lateral directions are reviewed.

• 한국정밀공학회지
• /
• 제15권3호
• /
• pp.99-106
• /
• 1998

Recently, scientists introduced a new type of microscope capable of investigating nonconducting surfaces in an atomic scale, which is called AFM (Atomic Force Microscope). It was an innovative attempt to overcome the limitation of STM (Scanning Tunnelling Microscope) which has been able to obtain the image of conducting surfaces. Surfaces of samples are imaged with atomic resolution. The AFM is an imaging tool or a profiler with unprecedented 3-D resolution for various surface types. The AFM technology, however, leaves a lot of room for improvement due to its delicate and fragile probing mechanism. One of the room for improvements is gap control between probe tip and sample surface. Distance between probe tip and sample surface must be kept in below one Angtrom in order to measure the sample surface in Angstrom resolution. In this paper, AFM system modeling, experimental system identification and control scheme based on system identification are performed and finally sample surface is measured by home-built AFM with such a control scheme.

• Tribology and Lubricants
• /
• 제29권4호
• /
• pp.213-217
• /
• 2013

As commercial atomic force microscopy (AFM) probes made of Si and $Si_3N_4$ have low stiffness, it is difficult to induce sufficient elastic deformation on the surface of a specimen in a tapping mode. Therefore, high-guality phase contrast images can not obtained. On the other hand, a tungsten AFM probe has relatively higher stiffness than a commercial AFM probe. Accordingly, it is expected to provide an enhanced phase contrast image, which is an effective tool for achieving a better understanding of the micromechanical properties of worn surfaces and wear mechanisms. In this study, on electrochemical etching method was optimized to fabricate tungsten probe tips for an AFM. Electrochemical etching was performed by applying pulse waves with a 20% duty cycle at various voltages instead of only a DC voltage, which has been commonly used.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2010년도 추계학술대회 논문집
• /
• pp.405-406
• /
• 2010

• International Journal of Precision Engineering and Manufacturing
• /
• 제9권3호
• /
• pp.27-32
• /
• 2008

This paper describes a contact atomic force microscope (AFM) that can be used for high-speed precision measurements of microstructured surfaces. The AFM is composed of an air-bearing X stage, an air-bearing spindle with the axis of rotation in the Z direction, and an AFM probe unit. The traversing distance and maximum speed of the X stage are 300 mm and 400 mm/s, respectively. The spindle has the ability to hold a sample in a vacuum chuck with a maximum diameter of 130 mm and has a maximum rotation speed of 300 rpm. The bandwidth of the AFM probe unit in an open loop control circuit is more than 40 kHz. To achieve precision measurements of microstructured surfaces with slopes, a scanning strategy combining constant height measurements with a slope compensation technique is proposed. In this scanning strategy, the Z direction PZT actuator of the AFM probe unit is employed to compensate for the slope of the sample surface while the microstructures are scanned by the AFM probe at a constant height. The precision of such a scanning strategy is demonstrated by obtaining profile measurements of a microstructure surface at a series of scanning speeds ranging from 0.1 to 20.0 mm/s.

• 대한화학회지
• /
• 제49권6호
• /
• pp.517-520
• /
• 2005

• Applied Microscopy
• /
• 제51권
• /
• pp.7.1-7.9
• /
• 2021

Neuromorphic systems require integrated structures with high-density memory and selector devices to avoid interference and recognition errors between neighboring memory cells. To improve the performance of a selector device, it is important to understand the characteristics of the switching process. As changes by switching cycle occur at local nanoscale areas, a high-resolution analysis method is needed to investigate this phenomenon. Atomic force microscopy (AFM) is used to analyze the local changes because it offers nanoscale detection with high-resolution capabilities. This review introduces various types of AFM such as conductive AFM (C-AFM), electrostatic force microscopy (EFM), and Kelvin probe force microscopy (KPFM) to study switching behaviors.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2002년도 ICCAS
• /
• pp.108.6-108
• /
• 2002

It is greatly important to understand the mechanics of AFM-based nanorobotic manipulation for efficient and reliable handling of nanoparticles. Robust motion control of an AFM-based nanorobotic manipulation is much challenging due to uncertain mechanics in tip-sample interaction dominated by surface and intermolecular force and limitations in force and visual sensing capability to observe environment. This paper investigates a nanomechanic modeling which enables simulation for AFM-based nanorobotic manipulation , and its application to motion planning of an AFM-based nanorobot. Based on the modeling of intermolecular and adhesion force in AFM-based nanomanipulation, the behaviors of an AFM ca...