• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권4호
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• pp.218-224
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• 2004

We present a miniature Direct Methanol Fuel Cell (micro-DMFC) using platinum sputtered microcolumn electrodes with a limited amount of fuel. We use the microcolumn electrode in order to improve the power density of the micro-DMFC that consists of two electrodes and polymer electrolyte. We also design the built-in fuel chamber in the anode for the portable electronics applications. We design and fabricate both microcolumn and planar electrodes, having an identical projective area of 5mm${\times}$5mm. The diffusion current density of the microcolumn electrode is 1.73 times higher than that of the planar electrode at electrode potential of 1.1V in the half-cell test. The micro-DMFC based on the microcolumn electrodes shows the maximum power of 10.8$\pm$7.54㎼(43.23$\pm$0.16㎼/$\textrm{cm}^2$) at the projective area of 5mm${\times}$5mm, while the planar electrode micro-DMFC shows the maximum power of 0.81$\pm$0.42㎼(3.24$\pm$1.68㎼/$\textrm{cm}^2$) at the same projective area. The micro-DMFC based on the microcolumn electrodes shows 13 times higher power density that the micro-DMFC based on the planar electrodes does.

• Journal of the Optical Society of Korea
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• 제15권4호
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• pp.368-372
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• 2011

An advanced microcolumn is proposed which adopts a modified einzel lens structure. The newly designed einzel lens is composed of four electrodes. The two center electrodes are specially designed electrostatic quadrupole (EQ) einzel lenses having keyhole instead of circular apertures. We constructed the advanced microcolumn with the EQ-einzel lenses, and operated the newly designed microcolumn in single lens mode and double-lens mode. The preliminary results show that the EQ-einzel lens can improve the performance of the micro-column for large sample applications.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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• pp.1037-1040
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• 2003

본 논문에서는 microcolumn 을 위한 초소형 전자빔 deflector 의 제작방법과 microcolumn array 에서 deflector 의 외부 패드를 최소화 할 수 있는 새로운 배선방법을 기술하였다. 배선의 통로 및 절연체 역할을 하는 Pyrex glass 의 양쪽에 각각 실리콘 웨이퍼의 양극접합 및 deep reactive ion etching(DRIE)과 금속 전기 도금을 이용하여 다층배선을 하였다. 이 배선방법을 이용하면 microcolumn array 가 수백개가 되더라도 deflector 의 외부 패드는 항상 8개를 유지할 수 있다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.78-78
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• 1999

Experimental studies of laser micromachining on Mo metal using piezo Q-switched Nd:YAG laser have been performed. Miniaturized microcolumn electron gun arrays as a potential electron beam lithography or portable mini-scanning electron microscope application have recently extensively examined. For these purpose, the electro-static electron lens and deflector system called microcolumn has to be assembled. The conventional microcolumn fabrication technique would gave a limitation on the minimization of aberration. The current technique of a 1 $\mu$m misalignment would lead to ~1.3 nm coma. In order to reduce aberration, assembling the microcolumn component followed by laser drilling should be very beneficial. In this report, we will address the preliminary report of laser micromachining on Mo substrate using piezo Q-switched Nd:YAG laser. The geometrical figures, such as the diameter and the depth of the frilled aperture are dependent upon the total energy of the laser pulse train, laser pulsewidth, and the diameter of laser beam in addition to the materials-dependent parameters.

• 한국재료학회지
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• 제14권3호
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• pp.186-190
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• 2004

An electron beam microcolumn composed of an electron emitter, micro lenses, scan deflector, and focus lenses have been fabricated and tested in the STEM mode. In this paper, we report a technique of precisely aligning the electron lenses by the laser diffraction patterns instead of the conventional alignment method based on aligner and STM. STEM images of a standard Cu-grid were observed using a fabricated microcolumn under both the retarding and accelerating modes.

• 한국광학회지
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• 제16권5호
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• pp.428-432
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• 2005

마이크로칼럼에 사용되는 전자렌즈는 MEMS 공정으로 정밀하게 가공되어 기존의 전자칼럼에 비하여 광학수차를 최소화 할 수 있으며, 이는 전자칼럼의 성능 향상에 주요한 요소로 작용한다. 따라서 반도체 공정 방식(습식식각과 건식식각)에 의해 형성되는 렌즈구조에 따른 전자 광학계 연구는 중요한 의미가 있다. 마이크로칼럼을 구성하고 있는 전자방출원, 소스렌즈, 디플렉터, 포커스렌즈(Einzel lens) 중에서 전자빔의 특성에 가장 큰 영향을 주는 것은 소스렌즈이다. 본 연구에서는 소스렌즈의 extractor와 limiting aperture의 구조에 따른 전자빔 특성을 조사하였다.

• 한국산학기술학회논문지
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• 제9권1호
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• pp.23-28
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• 2008

마이크로칼럼에 사용되는 전자렌즈는 MEMS 공정으로 정밀하게 가공되어 기존의 전자칼럼에 비하여 광학수차를 최소화 할 수 있으며, 이는 전자칼럼의 성능 향상에 주요한 요소로 작용한다. 습식 식각과 건식 식각에 의해 형성되는 전자렌즈의 모양과 배열조합에 따른 전자 광학계 연구는 중요한 의미가 있다. 마이크로칼럼은 전자방출원, source 렌즈, deflector, focus 렌즈(Einzel 렌즈)로 구성되는데, 전자빔의 특성에 가장 큰 영향을 주는 source 렌즈의 구성 요소 중 extractor와 limiting aperture의 모양에 따른 전자빔 특성을 조사하여 마이크로칼럼 제작에 있어서 최적화된 전자렌즈 조합을 도출하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.528-529
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• 2008

A new concept based on sample current measurements for detecting of via-hole defects on wafer has been performed by low energy electron beam microcolumn. The microcolumn has been operated at a low voltage of 290 eV with total emission current of 400 nA, and a sample current of 6 nA. The test sample was fabricated with SiO2 layer of 300 nm thickness on a piece of a silicon substrate. Preliminary results of both sample current method and secondary electron method show microcolumn and its control can be useful technology for detecting of via-hole defects on wafer.

• 반도체디스플레이기술학회지
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• 제20권4호
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• pp.29-37
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• 2021

A 7 nm technology node using extreme ultraviolet lithography with a wavelength of 13.5 nm has been recently developed and applied to the semiconductor manufacturing process. Furthermore, the development of sub-3 nm technology nodes continues to be required. In this study, design factors of an electrostatic deflector for an ultra-miniaturized microcolumn system that can realize an electron wavelength of below 1.23 nm with an acceleration voltage of above 1 eV were investigated using a three-dimensional simulator. Particularly, the optimal design of the electrostatic octupole floating deflector was derived by optimizing the design elements and improving the driving method of the 1 keV low energy ultra-miniaturized microcolumn deflector. As a result, the entire wide field of view greater than 330 ㎛ at a working distance of 4 mm was realized with an ultra-high-resolution electron beam spot smaller than 10 nm. The results of this study are expected to be a basis technology for realizing a wafer-scale multi-array microcolumn system, which is expected to innovatively improve the throughput per unit time, which is the biggest drawback of electron beam lithography.

• Journal of the Optical Society of Korea
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• 제14권2호
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• pp.127-130
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• 2010

We have developed an efficient electron beam (e-beam) source, a microcolumn, that can be used as a source module for of microscopy and its applications. To obtain a low operating voltage, a very sharp cold field electron emitter was developed by electrochemically etching a tungsten wire. Laser diffraction was used for the fabrication of high-quality electron lenses and for their precise alignment. The measurement of the e-beam currents, and SEM images captured by the microcolumn confirmed the potential of the device as a very good e-beam source.