• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1539-1542
• /
• 2005

Self-assembled monolayers (SAMs) formed by the adsorption of alkanethiols, $HS(CH_2)_nX$, where X is an organic functional group, onto gold surfaces have attracted widespread interest as templates for the fabrication of molecular and biomolecular microstructures. Previously photopatterning has been thought of as being restricted to the micron scale, because of the wellknown diffraction limit. So, we have explored a novel approach to nanofabrication by utilizing a femtosecond laser coupled to a near-field scanning optical microscope (NSOM).

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.187-190
• /
• 2002

Confocal microscopy is very popular technology in bio-medical inspection due to its ability to reject background signals and to measure very thin slide of thick specimens, which is called optical sectioning. But intensity of detected signal in fluorescence type confocal microscopy is so small that only 0.2% of emitted fluorescence light can be detected in the best case. In this paper, we proposed the reflecting optical system to improve the detection intensity and designed the optical system by optimal design method. At the end of the paper, we analyzed the characteristics of the proposed reflecting optical system.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.501-504
• /
• 2004

This paper describes the fabrication method for atomic force microscopy(AFM) tip with multi-walled carbon nanotube(MWNT). For making a carbon nanotube (CNT) modified tips, AC electric field which cause the dielectrophoresis was used for alignment and deposition of CNTs in this research. By dropping the MWNT solution and applying an electric field between an AFM tip and an electrode, MWNTs which were dispersed into a diluted solution were directly assembled onto the apex of the AFM tips due to the attraction by the dielectrophoretic force. In this case, we investigate the effect of the angle between a tip axis and an electrode. Experimental setup were presented, and then CNT attached AFM tips are successfully shown in this paper.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.29 no.11 s.242
• /
• pp.1503-1508
• /
• 2005

Scanning Thermal Microscope (STU) has been known for its superior resolution for local temperature and thermal property measurement. However, commercially available STU probe which is the key component of SThM does not provide resolution enough to explore nanoscale thermal phenomena. Here, we developed a SThM probe fabrication process that can achieve spatial resolution around 50 m. The batch-fabricated probe has a thermocouple junction located at the end of the tip. The size of the thermocouple junction is around 200 m and the distance of the junction from the very end of the tip is 150 m. The probe is currently being used for nanoscale thermal probing of nano-material and nano device.

• Korean Journal of Optics and Photonics
• /
• v.15 no.1
• /
• pp.51-55
• /
• 2004

Surface plasmons (SPs) are charge density oscillations that propagate along an interface between a dielectric and metal. In this paper, the electric field of SPs and the intereference of two SPs are observed by using Near-field Scanning Optical Microscope (NSOM). The excitation condition of SPs is changed as the optical tip approaches the metal surface, because the excitation condition of SPs is very sensitive to surface structures. To measure the microscope field of SPs, the distance between metal surface and optical tip must contain a specific interval.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.9
• /
• pp.2272-2283
• /
• 1994

In scanning tunneling microscopy, the piezoelectric actuator is popuilarly used in stacked type as it can provide remarkable positioning resolution and stiffness. The actuator, however, exhibits a considerable amount of hystereic nonlinearity, resulting in losses of overall measuring accuracy when a linear model is used for its control and calibration, In this study, a nonlinear model is proposed for predicting the precise relationship between the input connand voltage and the output displacement of the actuator itself, cross-coupled electrical behaviours of the driving circuit with the actuator, and mechanical characteristics of the driven components of the actuator. Finally experimental results prove that the nonlinear model enhances the measuring of scanning tunneling microscopy by an order ten in comparison with a conventional linear model.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.1048-1051
• /
• 2003

주사탐침현미경 (Scanning Probe Microsope, SPM)을 이용하여 직접 패터닝을 함으로써 hexanedithiol 분자의 임의 패턴을 금 표면에 형성하였다. 또한, hexanedithiol 분자는 양단에 thiol 그룹이 존재하여 금과 안정화 화학결합을 이룰 수 있으므로, 금 표면과결합을 이루고 있지 않는 상단의 thiol 그룹에 금 나노 입자를 고정함으로써 나노입자의 패턴을 제작하였다. SPM을 이용한 직접 패터닝 방법은 분자활성을 유지한 채로 임의 패턴을 수십 nm의 선폭으로 구현하는 것이 가능하므로, 나노입자 배열뿐만 아니라, 생화학물질의 패터닝을 통한 바이오 기술연구, 레지스트용 분자 패터닝과 시각 및 흡착 등의 계속적인 공정을 통한 다양한 나노구조 제작 등에 폭넓게 활용될 수 있다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.04a
• /
• pp.388-392
• /
• 2003

As the machine tool industry progresses, the performance of cutting tools also needs to be of good quality and specialized. If the existing metal cutting tool tip is coated properly, its life would be longer and the machining of a difficult-to-cut material also could be possible. For the development of the high quality cutting tool, the applicabilities of TiAIN coating deposited by PVD on the cutting insert were experimentally investigated. The various measurements, such as, SEM micrograph, XRD pattern, AFM surface morphology, and hardness were performed to cross-check the possibility and availability of TiAIN coated tool in the field. The effects of it is successful and we hope to see good results in many fields.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.5
• /
• pp.140-144
• /
• 2007

As an electron scanning microscopes has traditionally required a considerably large room equipped with several service and pipe lines due to its inherent size. As an alternative, a small sized SEM, simply called a mini-SEM, is introduced even if the performance in terms of magnification and resolution is a little inferior to a classical thermal SEM. However, the size and fabrication cost is dramatically reduced, dedicating to opening a new market. The optical system in the mini-SEM is redesigned and specimen stage is quitely reduced and vertical axis is excluded. The design tools and calibration techniques to develope the mini-SEM are introduced and its performance is verified through numerical analysis experiments.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.7
• /
• pp.829-836
• /
• 2003

Understanding of heat generation in semiconductor devices is important in the thermal management of integrated circuits and in the analysis of the device physics. Scanning thermal microscope was used to measure the temperature and the electric potential distribution on the cross-section of an operating metal-oxide-semiconductor field-effect transistor (MOSFET). The temperature distributions were measured both in DC and AC modes in order to take account of the leakage current. The measurement results showed that as the drain bias was increased the hot spot moved to the drain. The density of the iso-potential lines near the drain increased with the increase in the drain bias.