• Journal of Magnetics
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• 제14권1호
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• pp.31-35
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• 2009

Herein, the Magneto-Optical Kerr Effect (MOKE) signal enhancement in nanostructures in investigated. It is well known that the MOKE signals of ferromagnetic thin films are enhanced with an additional dielectric layer due to multiple reflections. The MOKE signal is modulated with the additional dielectric layer thickness and is at a maximum when reflectivity is at a minimum. This is not always true in the nanostructures due to the contribution from the non-magnetic substrate portion, especially when substrate reflectivity is minimized and the dependence of the additional dielectric layer thickness for the nanostructure is changed in the case of the continuous thin film. We showed that the MOKE signal for nanostructures could be enhanced with a properly designed, dielectric layer in addition to the anti-reflection coated substrates.

• 반도체디스플레이기술학회지
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• 제20권1호
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• pp.32-36
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• 2021

The number of processes in the manufacture of semiconductors, displays and solar cells is increasing. And as the processes is performed, multiple layers of films and various patterns are formed on the wafer. At this time, substrate warpage occurs due to the difference in stress between each film and pattern formed on the wafer. the substrate warping phenomenon occurs due to the difference in stress between each film and pattern formed on the wafer. We developed a new warpage measurement method to measure wafer warpage during real-time processing. We performed an experiment to measure the presence and degree of warpage of the substrate in real time during the process by adding only measurement equipment for applying additional electrical signals to the existing ESC and detecting the change of the additional electric signal. The additional electrical measurement signal applied at this time is very small compared to the direct current (DC) power applied to the electrostatic chuck whit a frequency that is not generally used in the process can be selectively used. It was confirmed that the measurement of substrate warpage can be easily separated from other power sources without affecting.

• 한국초전도ㆍ저온공학회논문지
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• 제15권2호
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• pp.29-33
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• 2013

The understanding of the strain dependence of critical current, $I_c$, in the reversible region is important for the evaluation of the performance of coated conductor (CC) tapes in practical applications. In this study, the stress/strain tolerance of $I_c$ in GdBCO CC tapes with stainless steel substrate stabilized by additional Cu and brass laminate was analyzed quantitatively through $I_c$-strain measurement at 77 K under self-field. The variation in irreversible strain limits of CC tapes by the addition of stabilizing layers was analyzed through the consideration of the pre-strain induced on the GdBCO coating film. The results were then compared with the ones previously reported for GdBCO CC tapes with Hastelloy substrate. As a result, GdBCO CC tapes with stainless steel substrate showed much higher strain tolerance of $I_c$ as compared with those adopting Hastelloy substrate.

• 센서학회지
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• 제24권3호
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• pp.159-164
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• 2015

Solid state electrochemical and chemo-resistive gas sensors have been used widely but can operate only under high temperature. For reducing the power consumption and optimizing the structure of the substrate of these sensors, we conducted device and circuit simulations using the COMSOL Multiphysics simulator. For assessing the effective types of substrate and heat isolation, we conducted three-dimensional thermal simulations in two separate parts; (a) by changing the shape of the contacting holes and (b) punching additional holes on the substrate. Thus, it was possible to achieve high temperature in the sensor end of the substrate while maintaining low power consumption, and temperature in the circuit.

• Journal of electromagnetic engineering and science
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• 제14권4호
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• pp.382-386
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• 2014

The knowledge of substrate material properties is important in antenna design. We present a technique to accurately characterize the dielectric constant and loss tangent of an antenna substrate based on the measurements of antenna's reflection coefficient and bandwidth. In this technique, an error function is formulated by combinations of the reflection coefficient and bandwidth of measured and simulated data, and then an optimization technique is used to efficiently search for the substrate properties that minimize the error function. The results show that the method is effective in retrieving the dielectric constant and loss tangent of the antenna substrate without the need of additional test fixtures as in conventional substrate characterization methods.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1260-1261
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• 2008

Aluminium doped zinc oxide (ZnO:Al) thin film has emerged as one of the most promising transparent conducting electrode in flat panel displays(FPD) and in photovoltaic devices since it is inexpensive, mechanically stable, and highly resistant to deoxidation. In this paper ZnO:Al thin film was deposited on the polyethylene terephthalate(PET) substrate by the capacitively coupled r.f. magnetron sputtering method. Wide ranges of bias voltage, -30V${\sim}$45V, was applied to the growing films as an additional energy instead of substrate heating, and the effect of positive and negative bias on the film structure and electrical properties of ZnO:Al films was studied and discussed. The results showed that a bias applied to the substrate during sputtering contributed to the improvement of electrical properties of the film by attracting ions and electrons in the plasma to bombard the growing films. These bombardments provided additional energy to the growing ZnO film on the substrate, resulting in significant variations in film structure and electrical properties. The film deposited on the PET substrate at r. f. discharge power of 200 W showed the minimum resistivity of about $2.4{\times}10^{-3}{\Omega}-cm$ and a transmittance of about 87%.

• 전자공학회논문지
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• 제49권12호
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• pp.173-178
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• 2012

RF 직접 추출 방법을 통해 얻은 정확한 MOSFET 기판 파라미터를 이용하여 기판저항만을 가진 BSIM4 모델은 스케일링 부정확성 때문에 넓은 영역의 게이트 길이에 적용하기에는 물리적으로 맞지 않다는 것이 증명됐다. BSIM4의 비물리적인 문제점을 제거하기 위해서 추가적인 유전체 기판 캐패시터를 가진 수정된 BSIM4 모델이 사용되었고, 이 모델의 물리적 타당성은 우수한 게이트 길이 scalability를 관찰함으로써 증명되었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.641-644
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• 2008

Traditional LTPS TFT needs additional LDD process to decrease leakage current. However the fabrication process is no suitable for PI substrate. Additional laser multi-irradiation will damage the poly-Si to cause the TFT electrical degrade. Therefore we propose the simplified process to activate the $N^+$ and $N^-$ at the same time.

• 한국광학회지
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• 제8권5호
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• pp.431-437
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• 1997

광신호 상호연결 및 입력물체의 결상을 위한 기존의 평판광학계에서는 굴절률이 일정한 유리기판을 광신호 전달매체로 사용하였는데 반하여, 본 연구에서는 물매-굴절률(gradient-index) 분포를 갖는 기판을 사용하는 새로운 개념의 평판광학계를 제안하였다. 물매기판에 의한 결상특성을 근축광선 추적에 의해 분석하였으며, 입력 광신호의 위치에 따라 결상된 위치가 변하는 실험결과로부터 새로운 결상광학계로의 응용 가능성을 검증하였다. 그리고, 물매기판을 이용한 평판광학계가 하나의 입력신호를 여러 출력면으로 동시에 분배할 수 있는 광신호처리계로도 응용될 수 있음을 제시하였다.

• Carbon letters
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• 제14권3호
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• pp.145-151
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• 2013

Graphene is a fascinating material with excellent electrical, optical, mechanical, and chemical properties. Remarkable progress has been made in the development of methods for synthesizing large-area, high-quality graphene. Recently, the chemical vapor deposition method has opened up the possibility of using graphene for electronic devices and other applications. This review covers simple and inexpensive methods to grow graphene using polymers as solid carbon sources; which do not require an additional process to transfer graphene from the growth substrate to the receiver substrate.