• Korean Journal of Materials Research
• /
• v.16 no.1
• /
• pp.30-36
• /
• 2006

A novel method was proposed to grow an epitaxial $CoSi_2$ on (100)Si substrate. A $CoN_x$ interlayer was deposited by reactive sputtering of Co in an Ar+$N_2$ flow. From the Ti/Co/$CoN_x$/Si structure, a uniform and thin $CoSi_2$ layer was epitaxially grown on (100)Si by annealing above $700^{\circ}C$. Two amorphous layers were found at the $CoN_x$/Si interface, where the top layer has a silicon nitride (Si-N) bonding state with some Co content and the bottom layer has a Co-Si intermixing state. The SiNx amorphous layer seems to play a critical role of suppressing the diffusion of Co into Si substrate for the direct formation of epitaxial $CoSi_2$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.22 no.2
• /
• pp.101-106
• /
• 2009

In this paper, Thin films of $HfO_2$/Hf were deposited on p-type wafer by Atomic Layer Deposition (ALD). We studied the electrical and material characteristics of $HfO_2$/Hf/Si MOS capacitor depending on thickness of Hf metal layer. $HfO_2$ films were deposited using TEMAH and $O_3$ at $350^{\circ}C$. Samples were then annealed using furnace heating to $500^{\circ}C$. Round-type MOS capacitors have been fabricated on Si substrates with $2000\;{\AA}$-thick Pt top electrodes. The composition rate of the dielectric material was analyzed using TEM (Transmission Electron Microscopy), XRD (X-ray Diffraction) and XPS (X-ray Photoelectron Spectroscopy). Also the capacitance-voltage (C-V), conductance-voltage (G-V), and current-voltage (I-V) characteristics were measured. We calculated the density of oxide trap charges and interface trap charges in our MOS device. At the interface between $HfO_2$ and Si, both Hf-Si and Hf-Si-O bonds were observed, instead of Si-O bond. The sandwiched Hf metal layer suppressed the growing of $SiO_x$ layer so that $HfSi_xO_y$ layer was achieved. And finally, the generation of both oxide trap charge and interface trap charge in $HfO_2$ film was reduced effectively by using Hf metal layer.

• Analytical Science and Technology
• /
• v.19 no.5
• /
• pp.407-414
• /
• 2006

An X-ray diffractometer for spatially resolved X-ray diffraction measurements was developed to identify phase in the narrow (micron-scaled) region of high burn-up fuels and some nuclear materials. The micro-XRD was composed of an X-ray microbeam alignment system and a sample micro translation system instead of a normal slit and a fixed sample stage in a commercial XRD. The X-ray microbeam alignment system was fabricated with a microbeam concentrator having two Ni deposited mirrors, a vertical positioner, and a tilt table for the generation of a concentrated microbeam. The sample micro translation system was made with a sample holder and a horizontal translator, allowing movement of a specimen at $5{\mu}m$ steps. The angular intensity profile of the microbeam generated through a concentrator was symmetric and not distorted. The size of the microbeam was $4,000{\times}20{\mu}m$ and the spatial resolution of the beam was $47{\mu}m$ at the sample position. When the diffraction peaks were measured for a $UO_2$ pellet specimen by this system, the reproducibility ($2{\Theta}={\pm}0.01^{\circ}$) of the peaks was as good as a conventional X-ray diffractometer. For the cross section of oxidized titanium metal, not only $TiO_2$ in an outer layer but also TiO near an oxide-metal interface was observed.

• Journal of Electrochemical Science and Technology
• /
• v.14 no.3
• /
• pp.231-242
• /
• 2023

Li₂O-based cathodes utilizing oxide-peroxide conversion are innovative next-generation cathodes that have the potential to surpass the capacity of current commercial cathodes. However, these cathodes are exposed to severe cathode-electrolyte side reactions owing to the formation of highly reactive superoxides (O^x-, 1 ≤ x < 2) from O^2- ions in the Li₂O structure during charging. Succinonitrile (SN) has been used as a stabilizer at the cathode/electrolyte interface to mitigate cathode-electrolyte side reactions. SN forms a protective layer through decomposition during cycling, potentially reducing unwanted side reactions at the interface. In this study, a composite of Li₂O and Ni-embedded reduced graphene oxide (LNGO) was used as the Li₂O-based cathode. The addition of SN effectively thinned the interfacial layer formed during cycling. The presence of a N-derived layer resulting from the decomposition of SN was observed after cycling, potentially suppressing the formation of undesirable reaction products and the growth of the interfacial layer. The cell with the SN additive exhibited an enhanced electrochemical performance, including increased usable capacity and improved cyclic performance. The results confirm that incorporating the SN additive effectively stabilizes the cathode-electrolyte interface in Li₂O-based cathodes.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.6 s.360
• /
• pp.1-7
• /
• 2007

This paper proposes CMOS semi-digital data recovery with 2X converse oversampling to reduce power consumption and chid area of high definition multimedia interface (HDMI) receivers. Proposed recovery can reduce its power and the effective area by using nt converse oversampling algorithm and semi-digital architecture. Proposed circuit is fabricated using 0.18um CMOS process and measured results demonstrated the power consumption of 14.4mW, the effective area of $0.152mm^2$ and the jitter tolerance of 0.7UIpp with 1.8V supply voltage.)

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2015.05a
• /
• pp.108-108
• /
• 2015

In order to investigate on hydroxyapatite precipitation phenomena on nanotubular Ti-29Nb-xHf ternary alloys, Ti-29Nb-xHf alloys contained (0% to 15%) Hf were manufactured using arc melting furnace. Formation of nanotubular structure was achieved by an electrochemical method in 1M $H_3PO_4$ electrolytes containing 0.8%wt. % NaF. Electrochemical deposition was carried out using cyclic and voltammetry(CV) method at $85^{\circ}C$ in $5mM\;Ca(NO_3)_2+3mM\;NH_4H_2PO_4$. HA coating on nanotube formed Ti-29Nb-xHf ternary alloys showed a good wettability.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2012.05a
• /
• pp.333-333
• /
• 2012

In this study, we investigated morphology of nanotube and micropore on the Ti-25Nb-xHf alloys with Hf contents after anodization. Ti-25Nb-xHf ternary alloys contained from (0~15) wt.% Hf contents were manufactured by vacuum arc-melting furnace. The obtained ingots were homogenized in an argon atmosphere at $1000^{\circ}C$ for 12h and then water quenching. The specimens were cut from ingots to 3mm thickness and first ground and polished using SiC paper (grades from 100 to 2000). 2steps anodization treatments on Ti-25Nb-xHf alloys were carried out at room temperature for experiments. Micro-pore formation was performed in Ca+P mixed solution at 265V for 3min. After that, nanotube formation was in 1M $H_3PO_4$ electrolytes containing 0.8wt.% NaF solutionat 10V for 120min. Morphologies of micropore and nanotube depended on the Hf content in Ti-25Nb-xZr ternary system.

• Transactions on Electrical and Electronic Materials
• /
• v.6 no.5
• /
• pp.229-232
• /
• 2005

Direct characterization of band alignment at chemical bath deposition $(CBD)-CdS/Cu_{0.93}(In_{1-x}Ga_x)Se_2$ has been carried out by photoemission spectroscopy (PES) and inverse photoemission spectroscopy (IPES). Ar ion beam etching at the condition of the low ion kinetic energy of 400 eV yields a removal of surface contamination as well as successful development of intrinsic feature of each layer and the interfaces. Especially interior regions of the wide gap CIGS layers with a band gap of $1.4\~1.6\;eV$ were successfully exposed. IPES spectra revealed that conduction band offset (CBO) at the interface region over the wide gap CIGS of x = 0.60 and 0.75 was negative, where the conduction band minimum of CdS was lower than that of CIGS. It was also observed that an energy spacing between conduction band minimum (CBM) of CdS layer and valance band maximum (VBM) of $Cu_{0.93}(In_{0.25}Ga_{0.75})Se_2$ layer at interface region was no wider than that of the interface over the $Cu_{0.93}(In_{0.60}Ga_{0.40})Se_2$ layer.

• Journal of Magnetics
• /
• v.10 no.4
• /
• pp.137-141
• /
• 2005

We confirmed that the improvement in properties of magnetic tunnel junctions prepared by radical oxidation after thermal treatment was mostly resulted from the redistribution of oxygen at the $AIOx/Co_{90}Fe_{10}$ interface. The as-deposited Al oxide barrier was oxygen-deficient but most of it re-oxidized into $Al_2O_3$, the thermodynamically stable stoichiometric phase, through thermal treatment. As a result, the effective barrier height was increased from 1.52 eV to 2.27 eV. On the other hand, the effective barrier width was decreased from 8.2 ${\AA}$ to 7.5 ${\AA}$. X-ray absorption spectra of Fe and Co clearly showed that the oxygen in the CoFe layer diffused back into the Al barrier and thereby enriched the barrier to close to a stoichiometirc $Al_2O_3$ phase. The oxygen bonded with Co and Fe diffused back by 6.8 ${\AA}$ and 4.5 ${\AA}$ after thermal treatment, respectively. Our results confirm that controlling the chemical structures of the interface is important to improve the properties of magnetic tunnel junctions.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.28 no.2
• /
• pp.53-59
• /
• 2005

The environment of If is, currently, on its developing process to the period of Web Service, Ubiquitous, and Telemetics which not only enable computer and internet to be utilized like the water or the air, but also be a new motivating force for its advance. In the respect of various interactions and User Interface, however, it is requiring more demands from its users, and additional functions which cannot be provided by the Web Browser. It is required a new model for supplementary of the limitation of Web_based according to their customers' requirement, to enrich the good aspects of Client-Server System, and accept such various intricate requirements. It is X-Internet, which has born with these requirements. In this study, therefore, it will be suggested a productive development framework and a method to perform the project on Rich-Thin Client Platform of X-Internet Based.