• Journal of the Korean Vacuum Society
• /
• v.6 no.2
• /
• pp.103-108
• /
• 1997

Silicon field emitter arrays (FEAs) have been fabricated by a novel method employing a two-step tip etch and a spin-on-glass (SOG) etch-back process using double layered thermal/tetraethylortho-silicate (TEOS) oxides as a gate dielectric. A partial etching was performed by coating a low viscous photo resist and $O_2$ plasma ashing on order to form the double layered gate dielectric. A small gate aperture with low gate leakage current was obtained by the novel process. The hight and the end radius of the fabricated emitter was about 1.1 $\mu\textrm{m}$ and less than 100$\AA$, respectively. The anode emission current from a 256 tips array was turned-on at a gate voltage of 40 V. Also, the gate current was less than 0.1% of the anode current.

• Journal of the Korean Magnetics Society
• /
• v.19 no.1
• /
• pp.35-42
• /
• 2009

Among the next generation memory, MRAM (Magnetic Random Access Memory) is worthy of notice for substituting the preexisting memory thanks to its non-volatile property and other advantages. Recently perpendicular MRAM and spin transfer torque MRAM techniques are under active investigation to realize a high density and low power consumption. As a result, there are increasing of patents applications for high density, low current density for magnetization switching and high thermal stability. In this paper, we analyze the trend of patent applications and registrations about MRAM and propose a direction of future investigation.

• Journal of the Microelectronics and Packaging Society
• /
• v.23 no.1
• /
• pp.11-15
• /
• 2016

The organic light emitting diodes (OLEDs) have been studied as large flexible displays, light source and hard wares of internet of things. However, OLEDs show some drawbacks in terms of external environments due to the low work function of the metals and the reactive organic materials. In particular, the operation functions of the OLEDs tend to deteriorate rapidly by exposing the oxygen and moisture. So as to prevent it, domestic and overseas studies underway in various method such as ALD, PVD, CVD. But it has complex process and high cost. Therefore In order to protect devices from the external environments, it is important to develop the passivation thin films of low-cost and simple process which can prevent the devices from the penetration of the oxygen and moistures. In this study, to improve the reliability, passivation thin films were coated onto the green OLEDs by spin coating method and investigated the changes of the optical properties of the prepared devices at various doping concentrations of sodium alginate (SA). The passivation solutions were synthesized by using polyvinyl alcohol (PVA) host material with a dopant of SA which were added with the amounts of 10, 20 and 40 wt% into the PVA. As a result, the best barrier properties of the OLEDs were obtained for the samples with 40 wt% SA. Finally, the passivation films can be optimized by using the mixture solution of PVA and SA materials.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.399-399
• /
• 2008

Synthesis and characterization of ZnO structure such as nanowires, nanorods, nanotube, nanowall, etc. have been studied to multifunctional application such as optical, nanoscale electronic and chemical devices because it has a room-temperature wide band gap of 3.37eV, large exiton binding energy(60meV) and various properties. Various synthesis methods including chemical vapor deposition (CVD), physical vapor deposition, electrochemical deposition, micro-emulsion, and hydrothermal approach have been reported to fabricate various kinds of ZnO nanostructures. But some of these synthesis methods are expensive and difficult of mass production. Wet chemical method has several advantage such as simple process, mass production, low temperature process, and low cost. In the present work, ZnO nanorods are deposited on ITO/glass substrate by simple wet chemical method. The process is perfomed by two steps. One-step is deposition of ZnO seeds and two-step is growth of ZnO nanorods on substrates. In order to form ZnO seeds on substrates, mixture solution of Zn acetate and Methanol was prepared.(one-step) Seed layers were deposited for control of morpholgy of ZnO seed layers by spin coating process because ZnO seeds is deposited uniformly by centrifugal force of spin coating. The seed-deposited samples were pre-annealed for 30min at $180^{\circ}C$ to enhance adhesion and crystallinnity of ZnO seed layer on substrate. Vertically well-aligned ZnO nanorods were grown by the "dipping-and-holding" process of the substrates into the mixture solution consisting of the mixture solution of DI water, Zinc nitrate and hexamethylenetetramine for 4 hours at $90^{\circ}C$.(two-step) It was found that density and morphology of ZnO nanorods were controlled by manipulation of ZnO seeds through rpm of spin coating. The morphology, crystallinity, optical properties of the grown ZnO nanostructures were carried out by field-emission scanning electron microscopy, high-resolution electron microscopy, photoluminescence, respectively. We are convinced that this method is complementing problems of main techniques of existing reports.

• Journal of Magnetics
• /
• v.7 no.3
• /
• pp.98-100
• /
• 2002

Tunnel magnetoresistive devices using an individual multi-walled carbon nanotube were fabricated and their low-temperature electrical transport propertiers were investigated. With the ferromagnetic Co electrodes, the multi-walled carbon nanotube exhibited hysteretic magnetoresistance curve at low temperatures. Depending on the temperature and the bias current, the magnetoresistance ratio can be as high as 16% at the temperature of 2.2 K. Such high magnetoresistance ratio indicates a long diffusion length of the multi-walled carbon nanotube.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.1451-1454
• /
• 2005

We report effects of inorganic binder on the emission properties of CNT paste for low cost and high low-cost and large area field emission devices or displays. Two types of photosensitive carbon nanotube (CNT) paste were formulated by using of glass frit and spin on glass (SOG) as an inorganic binder and investigated their emission properties according to inorganic binders and firing conditions.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.1466-1469
• /
• 2005

We report effects of electrical aging on the emission stability of carbon nanotube (CNT) paste for low cost and high low-cost and large area field emission devices or displays. Photosensitive carbon nanotube paste was formulated by using of spin on glass (SOG) as an inorganic binder and investigated emission properties and stability depending on electrical aging condition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.12
• /
• pp.1106-1110
• /
• 2005

We fabricated (110) silicon hard master by using anisotropic wet etching for embossing. The etching chemical for the silicon wafer was a TMAH $25\%$ solution. The anisotropic wet etching produces a smooth sidewall surface and the surface roughness of the fabricated master is about 3 nm. After spin coating an organic-inorganic sol-gel hybrid material on a silicon substrate, we employed hot embossing technique operated at a low pressure and temperature to form patterns on the silicon substrate by using the fabricated master. We successfully fabricated the multi-mode planar optical waveguides showing low propagation loss of 0.4 dB/cm. The surface roughness of embossed patterns was uniform for more than 10 times of the embossing processes with a single hydrophobic surface treatment of the silicon hard master.

• KIEE International Transactions on Electrophysics and Applications
• /
• v.11C no.2
• /
• pp.18-22
• /
• 2001

The thin films of high permitivity in ferroelectric materials using a capacitor are applied to DRAMs and FRAMs. (Ba, Sr)TiO$_3$ thin as ferroelectric materials were prepared by the sol-gel method and made by spin-coating on the Pt/Sio$_2$/Si substrate at 4,000 [rpm] for 10 seconds. The structural characteristics of the surface were analyzed by fractal dimension. The thickness of BST ceramics thin films was about 260∼280 [nm]. The property of the leakage current was stable with 10-9∼10-11[A] when the applied voltage was 0∼3[V]. BST thin films ha low leakage current properties when fractal dimension was low and a coating area was high.

• Journal of the Korean Magnetic Resonance Society
• /
• v.23 no.3
• /
• pp.73-80
• /
• 2019

Nitrogen-vacancy (NV) is one of the most popular solid-state spin systems for quantum sensing. NV has been used for vector magnetometry with nanometer spatial resolution and sensors for nuclear magnetic resonance (NMR) in samples with small volume, less than 10 pL. Various studies are in progress to make NV a complementary sensor for current NMR technique. Fabricating and improving diamond itself are one of the research topics. This mini-review contains recent develops in diamond fabrication and treatment for higher NV yield. Additionally, we briefly introduce the development status of NV in NMR.