• Journal of Biomedical Engineering Research
• /
• v.22 no.2
• /
• pp.145-150
• /
• 2001

대뇌 피질에 삽입하여 깊이에 따라 신경 신호를 기록하기 위한 탐침형 반도체 미세전극 어레이(depth-type silicon microelectrode array, 일명 SNU probe)를 제작하였다. 붕소를 확산시켜 생성된 고농도 p-type doping된 p＋ 영역을 습식식각 정지점으로 사용하는 기존의 방법과 달리 실리콘 웨이퍼의 앞면을 건식식각하여 원하는 탐침 두께만큼의 깊이로 트렌치(trench)를 형성한 후 뒷면을 습식식각하는 방법으로 탐침 형태의 미세 구조를 만들었다. 제작된 반도체 미세전극 어레이의 탐침 두께는 30 $\mu\textrm{m}$이며 실리콘 건식식각을 위한 마스크로 6 $\mu\textrm{m}$ 두께의 LTO(low temperature oxide)를 사용하였다. 탐침의 두께는 개발된 본 공정을 이용해서 5~90 $\mu\textrm{m}$ 범위까지 쉽게 조절할 수 있었다. 탐침의 두께를 보다 쉽게 조절할 수 있게 됨에 따라 여러 신경조직에 필요한 다양한 구조의 반도체 미세전극 어레이를 개발할 수 있게 되었다. 본 공정을 이용해서 개발된 4채널 SUN probe를 사용하여 흰쥐의 제1차 체감각 피질에서 4채널 신경 신호를 동시에 기록하였으며, 전기적 특성검사에서 기존의 탐침형 반도체 미세전극, 텅스텐 전극과 대등하거나 우수한 신호대 잡음비(signal to noise ratio, SNR)특성을 가짐을 확인하였다.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.49 no.7
• /
• pp.375-381
• /
• 2000

In this paper, we described the characterization of High-Tc Superconducting(HTS) microstrip antenna using non-radiating edge feeding technique and reported the microwave properties of HTS antennas with temperature. To do this, we prepared the $YBa_2Cu_3O_{7-x}$ superconducting thin film on MgO substrate using pulse-laser deposition techniques. The HTS microstrip antenna using non-radiating feeding technique was fabricated using chemical wet-etching. Then it was compared with identical antenna patterned with evaporated gold. The diverse measured results have been reported in terms of the input impedance, resonant frequency and return loss. In additional, at around the critical temperature, the effect of kinetic inductance which affect the resonant characteristic of the HTS microstrip antenna was reported.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.04a
• /
• pp.91-94
• /
• 2007

The fabrication and firing test of the ignition system for a micro solid propellant thruster are described in the present paper. Pt igniter coil was patterned on the glass membrane that was fabricated by the wet etching process. The thickness of Pt layer was $2000{\AA}$ and the width of igniter pattern was $40{\mu}m$. The thickness and diameter of glass membrane were $15{\mu}m$ and 1 mm, respectively. Ignition test was performed. Successful ignition of HTPB/AP propellant was obtained with an ignition delay of 1.6 s at an input voltage of 12 V. The ignition energy was estimated to be 1.4 J.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.05a
• /
• pp.275-277
• /
• 1999

A application possibility of photoresist flexible film for optical waveguide is proposed and described. The optical waveguide dimensions that is consists of Mach-zehnder interferometric and single channel waveguide based on the single-mode conditions in LiNbO$_3$ device was utilized and fabricated by wet etching technique. This Polymer material for core layer is SU-8/5O(Microchem.) and its refractive index from prism couping method was measured about 1.59 thickness about 10${\mu}{\textrm}{m}$ at wavelength 0.6328${\mu}{\textrm}{m}$. From the results, this work can show the possibility of fabricating a flexible optical waveguide in the field of integrated optics.

• Journal of the Semiconductor & Display Technology
• /
• v.10 no.1
• /
• pp.91-94
• /
• 2011

This paper presents light transmission efficiency by optical adhesive thickness between MLA and aperture layer and by aperture hole size. The gap between MLA and Aperture layer is adjusted by the shim. The more optical adhesive thickness increases, the better light transmission efficiency increases up to a point. After that, the light transmission efficiency decreases because stray lights cannot transmit through the aperture layer owing to cut-off by aperture layer. And as a result of light transmission efficiency with changing aperture hole size, the light transmission efficiency is proportional to area of aperture hole. The more specified process is made, the better data and sample will be got.

• 한국태양에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.383-387
• /
• 2009

Multi-crystalline silicon surface etching without grain-boundary delineation is a challenging task for the fabrication of high efficiency solar cell. The use of sodium hydroxide - sodium hypochlorite (NaOH40% + NaOCl 12%) solution for texturing multi-crystalline silicon wafer surface in solar cell fabrication line is reported in this article. in light current-voltage results, the cells etched in NaOH 40% + NaOCl 12% = 1:2 exhibited higher short circuit current and open circuit voltage than those of the cells etched in NaOH 40% + NaOCl 12% = 1:1 solution. we have obtained 15.19% conversion efficiency in large area(156cm2) multi-Si solar cells etched in NaOH 40% + NaOCl 12% = 1:1 solution.

• Transactions on Electrical and Electronic Materials
• /
• v.3 no.1
• /
• pp.4-8
• /
• 2002

The typical mold method for FED (field emission display) fabrication is used to form a gate electrode, a gate oxide layer, and emitter tip after fabrication of a mold shape using wet-etching of Si substrate. However, in this study, new mold method using a side wall space structure was developed to make sharp emitter tips with the gate electrode. In new method, gate oxide layer and gate electrode layer were deposited on a Si wafer by LPCVD (low pressure chemical vapor deposition), and then BPSG (Boro phosphor silicate glass) thin film was deposited. After then, the BPSG thin film was flowed into the mold at high temperature in order to form a sharp mold structure. TiN was deposited as an emitter tip on it. The unfinished device was bonded to a glass substrate by anodic bonding techniques. The Si wafer was etched from backside by KOH-deionized water solution. Finally, the sharp field emitter array with gate electrode on the glass substrate was formed.

• Journal of the Microelectronics and Packaging Society
• /
• v.6 no.4
• /
• pp.15-22
• /
• 1999

Generally, many equipments and a long lead time ale required to manufacture the build-up multilayer board through various processes such as etching, plating, drilling etc. Wet process is suitable for mass production, however it is not adequate for manufacturing prototype in developing stage. In this study, a silk screen printing technology is introduced to make a prototype build-up multilayer board. As for the material photo/thermal curable resin and conductive paste are used for forming dielectric and conductor. And conductive paste fills vias for interconnecting each layer, and also is used for circuit patterning by silk screen technology. Finally, the basic concept and the possibility of build-up multilayer board prototype is proposed and verified as a powerful approach, compared with the conventional processes.

• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1623-1624
• /
• 2006

It is a paper for design, manufacture and estimation of industry inkjet head. Simulations for Actuator, Ink flow and Ejection are executed for securing design ability. Relations between droplet and properties of ink are explained closely through simulation for nozzle. Actually, two silicon plates are made by dry and wet etching and directly bonded. PZT materials is attached on the bended ink flow part and cut to $540{\mu}m$ interval by dicing saw. Actuator was seen variation within 10% between simulation and actual head. Through the ejection estimation, it is shown that stabilized driving voltages change according to viscosity and surface tension of metal ink. Using the metal ink of viscosity of 4.8 cps and surface tension of 0.025 N/m, it is possible to eject the stable droplets with 5m/s, 20 pl, 5 kHz.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.655-656
• /
• 2005

In the future, plastic based system will play a crucial role in modem life, for examples, transparent display or disposable electronics and so on. In this paper, we introduced a new method to fabricate the metal line on the plastic substrate. Metal lines were fabricated by hot embossing and CMP process on PMMA (polymethylmethacrylate) substrates. A Si mold was made by wet etching process and a PMMA wafer was cut off from I mm thick PMMA sheet. A 100 nm thick Al was deposited on PMMA wafers. The Al deposited PMMA wafer and the Si mold carefully sandwiched which was directly imprinted by hot embossing. After imprinting process, a residual Al layer was removed by CMP process. Finally, we found the entire process may be very useful to fabricate the metal line on plastic substrates.