• 한국생산제조학회지
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• 제20권5호
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• pp.517-522
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• 2011

Most of SEM is double condenser lens system. Two condenser lenses are required to provide the high demagnification ratios necessary for forming nanometer probes. The thin lens concept provides a highly useful basis for preliminary calculations in a broad range of situations. It is an easy way to understand the electron beam paths in column. Demagnification is easily calculated by this method. In this paper, we present design processes for condenser lens's demagnification by using thin lens combination model. Also, we verify the reliability of our design processes by comparing the modeled demagnification with these of corrected condenser lens.

• 한국생산제조학회지
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• 제24권3호
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• pp.270-277
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• 2015

In this paper, we describe the production of a specific electrostatic-type scanning electron microscope based on miniaturization for application in other types of vacuum equipment. The initial configuration of the SEM starts with a minimal configuration that allows people to view sample images. After improving the stability of the SEM operation and resolution, we conducted experiments on identifying the characteristics and development of an einzel-type condenser lens with reference to the demagnification lens system of an SEM. The experiments were conducted at an acceleration voltage of 5 kV and we found the shape of the lens to be more reliable than a conventional lens. The lens was then added to improve the resolution in the nanometer region. The current measured on the sample was approximately 40 pA and its magnification was 4,000 times.

• 한국공작기계학회논문집
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• 제16권5호
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• pp.96-100
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• 2007

Condenser lens and objective lens are used to demagnify the image of the crossover to the final spot size. In lens, electrons are focused by magnetic fields. This fields is fringing field. It is important in electron focusing. Electron focusing occurs the radial component field and axial component field. Radial component produces rotational force and axial component produces radial force. Radial force causes the electron's trajectory to curve toward the optic axis and corss it. Focal length decreases as the current of lens increases. In this paper, we use the focal length for desiging the hardware of lens current control and present the results.

• 한국정밀공학회지
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• 제20권2호
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• pp.33-39
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• 2003

A new microlens fabrication technique, the excimer laser lithography is developed. This bases on the pulsed laser irradiation and the transfer of a chromium-on-quartz reticle on to the polymer surface with a proper projection optics system. An excimer laser lithography system with 1/4 and 1/20 demagnification ratios was constructed first, and the photoablation characteristics of the PMMA and Polyimide were experimentally examined using this system. For two different shapes of microlenses, a spherical lens and a cylindrical lens, fabrication techniques were investigated. One for the spherical lens is a combination of the mask pattern projection and fraction effect. The other for the cylindrical lens is a combination of the mask pattern projection and the relative movement of a specimen. The result shows that various shapes of micro optical components can be easily fabricated by the excimer laser lithography.

• Journal of the Optical Society of Korea
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• 제19권1호
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• pp.29-37
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• 2015

The wavefront printer records a volume-reflection hologram as a two-dimensional array of elemental holograms from computer-generated holograms (CGHs) displayed on a spatial light modulator (SLM). The wavefront coming from the object is extracted by filtering in the spatial-frequency domain. This paper presents a method to improve color reproduction in a wavefront printer with spatial division of exposures at primary colors, by adaptive partitioning of the SLM in accordance with the color content encoded in the input CGHs, and by the controllable change of exposure times for the recording of primary colors. The method is verified with a color wavefront printer with demagnification of the object beam. The quality of reconstruction achieved by the proposed method proves its efficiency in eliminating the stripe artifacts that are superimposed on reconstructed images in conventional mosaic recording.

• 대한기계학회논문집A
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• 제39권1호
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• pp.1-9
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• 2015

이 논문은 SEM(Scanning Electron Microsopy) 경통부에서 전자빔의 집속특성을 최적화하기 위한 방법을 다루고 있다. SEM 에서 물체 표면을 확대하기 위해서는 경통부를 지나는 전자빔을 효과적으로 집속하여 표면에 충돌하는 프로브 직경을 줄이는 것이 중요하다. 이 전자빔의 집속정도를 나타내는 지표가 반배율이다. 본 연구는 전자빔의 집속특성을 효과적으로 구현하기 위해 그에 영향을 끼치는 경통부의 설계 인자들을 렌즈 해석과 광선 추적을 통해 알아본다. 이 결과를 근거로 민감도 분석을 수행하여 설계 인자들이 빔의 집속에 끼치는 영향의 정도를 정량적으로 비교해 볼 수 있다. 이러한 전자빔의 특성에 따른 설계 인자의 분석은 경통부 설계에 있어 중요한 기초 정보로 활용될 수 있다.

• 한국진공학회지
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• 제10권3호
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• pp.380-386
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• 2001

정밀가변슬릿과 자기사중극렌즈로 구성된 핵 마이크로프로브 (nuclear microprobe) 시스템을 일차행렬법을 이용한 빔광학 전산모사를 통해 설계하였으며, 제작된 시스템을 KIGAM 1.7 MV 탄뎀 반데그라프 가속기의 $30^{\circ}$ 빔라인에 설치하였다. X 및 Y축에 대한 역배율은 각각 25와 4.9로 계산되며, 3 MeV 양성자빔의 경우 최소 빔크기는 약 5 미크론, 빔전류는 약 1 nA 정도로 추산된다. PIXE, RBS, ERDA등 MeV 이온빔분석법과 이온빔 미세가공을 위해 다목적 8각형 표적함을 제작하였으며, 표적함은 X-선 및 하전입자검출기, 줌현미경, 파라데이컵, 4축 시료이송계 및 고진공계로 구성되어 있다. 현재 핵 마이크로프로브 시스템 성능 조사가 이루어지고 있으며, 자동화된 시료 이송 및 자료 처리 시스템이 설치되면 일상적인 마이크로 이온빔 분석이 가능해 질 것으로 예상된다.