• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.956-959
• /
• 2002

In this work, a new non-lithographic micro-fabrication technique is presented. The motivation of this work is to overcome the demerits of the most commonly used photo-lithographic techniques. The micro-fabrication technique presented in this work is a two-step process which consists of mechanical scribing followed by chemical etching. This method has many advantages over other micro-fabrication techniques since it is simple, cost-effective, rapid, and flexible. Also, the technique can be used to obtain a metal structure which has sub-micrometer width patterns. In this paper, the concept of this method and its application to microsystem technology are described.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.12
• /
• pp.29-36
• /
• 2004

In this paper, a new replication technique for a real 3D microstructure was introduced, in which a master Pattern WES made of photo-curable epoxy using a microstereolithography technology, and then it was transferred onto an epoxy-copper particle composite. A helical gear was selected as one of the real 3D microstructure for this study, and it was replicated from a pure epoxy to an epoxy composite. In addition, the transferability of the microreplication process was evaluated, and the properties of :he epoxy composite were compared to that of the pure epoxy, including hardness, wear-resistance and thermal conductivity.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2003.03a
• /
• pp.140-140
• /
• 2003

Ti:LiNbO$_3$ 광 도파로를 이용한 광 변조기의 마이크로파 손실을 감소시키고 RF와 광파의 속도정합의 조건하에서 초고속 광변조의 제작을 위해서는 두꺼운 TW(travelling wave) 전극이 필수적이다 또한, 두꺼운 Au 전극이 우수한 RF 특성을 갖기 위해서는 도금된 Au 전극이 고순도의 작은 grain size를 갖는 도금 층을 제조하여야 하며, 도금 후 Au 층의 뒤틀림 현상이 작아야 한다. 따라서, 본 연구에서는 LiNbO$_3$ 기판 위에 30nm Ni-Cr과 50nm의 Au의 기저 막을 올렸으며 감광제를 이용한 photo-lithography 공정으로 CPW(coplanar waveguide) 구조의 패턴을 약 13$\mu\textrm{m}$의 두께로 형성 한 후 non-cyanidic 액을 이용하여 전류밀도 0.02 - 0.06 mA, bubble 및 non-bubble flow를 조건으로 하여 도금된 Au 전극의 특성을 관찰하였다.

• Transactions on Electrical and Electronic Materials
• /
• v.14 no.3
• /
• pp.156-159
• /
• 2013

The electrical properties of ZnO nanowire field effect transistors (FETs) have been investigated depending on various diameters of nanowires. The ZnO nanowires were synthesized with an Au catalyst on c-plane $Al_2O_3$ substrates using hot-walled pulsed laser deposition (HW-PLD). The nanowire FETs are fabricated by conventional photo-lithography. The diameter of ZnO nanowires is simply controlled by changing the thickness of the Au catalyst metal, which is confirmed by FE-SEM. It has been clearly observed that the ZnO nanowires showed different diameters simply depending on the thickness of the Au catalyst. As the diameter of ZnO nanowires increased, the threshold voltage of ZnO nanowires shifted to the negative direction systematically. The results are attributed to the difference of conductive layer in the nanowires with different diameters of nanowires, which is simply controlled by changing the catalyst thickness. The results show the possibility for the simple method of the fabrication of nanowire logic circuits using enhanced and depleted mode.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.11a
• /
• pp.123-124
• /
• 2006

본 연구에서는 KOH 용액을 사용한 Si 습식 이방성 식각실험 진행 후, 나타나는 표면의 거친 현상을 완화하는 데에 중점을 두고 연구를 진행하였다. 이를 위해 $SiO_2$ 웨이퍼 위에 Photo-lithography 공정으로 형성시킨 PMER 패턴을 Mask로 사용하여 HF 용액으로 $SiO_2$를 식각시켰으며, 형성된 $SiO_2$를 Mask로 사용하여 KOH 용액으로 Si을 식각시켰다. 이 때, KOH와 혼합하는 용액으로 IPA와 Ethan이을 각각 사용하여 실험을 진행하였으며, ESEM을 이용하여 표면을 비교하였다.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2011.05a
• /
• pp.2.3-2.3
• /
• 2011

With increased interest in printed devices, various metal nano inks have been investigated as candidates materials for printed electrodes and wiring as well as conductive film substituting photo-lithography process. Recent advances in organic conductive polymer allow us to fabricate high performance printed device. Meanwhile, there was several attempts to fabricate conductive films by mixing conductive polymer with metal nano-particle or nano-wires. The presence of Ag nanowires in conductive polymer mixture have shown good potential in organic photovoltaic devices.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.3
• /
• pp.731-736
• /
• 2014

An organic junction transistor with a vertical structure based on an active layer of poly(3-hexylthiophene) was fabricated by facile micro-contact printing combined with the Langmuir-Schaefer technique, without conventional e-beam or photo-lithography. Direct printing and subsequent annealing of Au-nanoparticles provided control over the thickness of the Au electrode and hence control of the electrical contact between the Au electrode and the active layer, ohmic or Schottky. The junction showed similar current-voltage characteristics to an NPN-type transistor. Current through the emitter was simply controllable by the base voltage and a high transconductance of ~0.2 mS was obtained. This novel fabrication method can be applied to amplifying or fast switching organic devices.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1229-1232
• /
• 2006

We have grown well-aligned carbon nanotube arrays on the selective areas by plasma enhanced chemical vapor deposition at the substrate temperature of $580\;^{\circ}C$. The selective areas for CNTs growth can be defined by photo lithography technology. The CNTs are uniformly grown on the areas regardless of island diameters. Electron emission currents were measured in a vacuum with a diode structure at room temperature. Uniform electron emission currents were achieved with $40\;{\mu}m$ island spacing with $5{\mu}m$ island diameter.

• ETRI Journal
• /
• v.29 no.4
• /
• pp.452-456
• /
• 2007

Very compact 4-channel 200-GHz-spacing external cavity lasers (ECLs) were fabricated by hybrid integration of reflection gratings and superluminescent laser diodes on a planar lightwave circuit chip. The fifth-order gratings as reflection gratings were formed using a conventional contact-mask photo-lithography process to achieve low-cost fabrication. The lasing wavelength of the fabricated ECLs matched the ITU grid with an accuracy of ${\pm}0.1$ nm, and optical powers were more than 0.4 mW at the injection current of 80 mA for all channels. The ECLs showed single mode operations with more than 30 dB side lobe suppression.

• Molecular & Cellular Toxicology
• /
• v.2 no.4
• /
• pp.279-284
• /
• 2006

This paper describes the fabrication methods of a carbon nanotube (CNT) filter and a microdialysis chip. A CNT filter can help perform dialysis on a microfluidic chip. In this study, a membrane type of a CNT filter is fabricated and located in a microfluidic chip. The filter plays a role of a dialysis membrane in a microfluidic chip. In the fabrication process of a CNT filter, individual CNTs are entangled each other by amide bonding that is catalyzed by 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The chemically treated CNTs are shaped to form a CNT filter using a PDMS film-mold and vacuum filtering. Then, the CNT filter is sandwiched between PDMS substrates, and they are bonded together using a thin layer of PDMS prepolymer as adhesive. The PDMS substrates are fabricated to have a microchannel by standard photo-lithography technique.