• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2012.05a
• /
• pp.213-213
• /
• 2012

In this study, effect of EB-PVD coated Si/HA film thickness on surface characteristics of Ti-35Nb-10Zr alloy was investigated. The Ti-35Nb-10Zr alloy was fabricated by arc melting method. The Si/HA layers were coated with 0.8 wt.% of Si in pure HA by EB-PVD method. The coating thickness was consisted with 100 - 300 nm for each group, the surface characteristics was analyzed by FE-SEM, EDS, XRD, XRF and corrosion test. The Si/HA coating layer was well deposited on the alloy surface by EB-PVD, the thickness was correlative factor with HA peaks and corrosion resistance value.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.25 no.11
• /
• pp.1294-1303
• /
• 1988

Electron and hole traps in semi-insulating GaAs with activation energies ({\Delta}E_r) ranging from 0.16 $\pm$ 0.01 to 0.98 $\pm$ 0.01 eV, have been detected and characterized by photo-induced current transient measurements. SI undoped GaAs has fewer deep levels than SI GaAs: Cr. The thermal capture cross section and density of the traps have been estimated and some of the centers have been related to native defects. In particular, the activation energy of the compensating Cr, and "0" levels in semi-insulating GaAs were accurately measured. The transient measurements were complemented by Hall measurements at T > 300K and photocurrent spectra measurements. The transition energies for the deep compensating levels obtained by the analyses of data from these measurements, when compared with those from the transient measurements, indicate negligible lattice-coupling of these centers. Analysis of the transport data also indicates that neutral impurity scattering plays a significant role in semi-insulating materials at high temperatures.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.91-91
• /
• 2011

박막태양전지의 높은 효율개선을 위해 TCO층과 p-layer 사이에 buffer layer를 넣어 Voc와 FF를 개선하는 연구가 진행되고 있다. 이에 buffer layer의 활성화 정도를 높이기 위해 p-layer을 최적화 시키고자한다. 이 실험에서 a-Si:B에 N2O를 도핑시켜 Bandgap Energy 2.0 eV, Activation Energy 0.4 eV인 a-SiOx:B 막을 제작하여 buffer layer로 사용하였고 이 buffer layer에 의한 cell의 효율 향상을 최적화 하기위해 ASA simulation을 이용해 p-layer의 Bandgap Energy와 Activation Energy를 가변 하여 보았다. 실험결과 p-layer의 Bandgap Energy 1.95 eV에서 buffer layer와 p-layer사이에서의 barrier가 최소가 됨을 확인 할 수 있었고 Actication Energy 0.5 eV에서 가장 높은 Voc를 가짐을 알 수 있었다. 본 연구를 통해 p-layer의 Bandgap Energy 1.95 eV, Activation Energy 0.5 eV에서 buffer layer를 활성화시키기 위한 p-layer의 최적화 조건을 구현해 볼 수 있었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.7
• /
• pp.557-563
• /
• 2003

SiC has been an useful material for the high voltage, high temperature, and high frequency devices, however, the required high process temperature to activate the implanted p-type dopants has hindered further developments. In this study, we report, for the first time, on the laser activation of implanted Al and non-alloyed Mo ohmic contacts and its application to MOSFET fabrication. The contact and sheet resistance measured from CTLM patterns have decreased by increasing laser power, and the lowest values are 3.9 $K\Omega$/$\square$ and 1.3 $\times$ 10$^{-3}$ $\Omega$-cm$^2$, respectively, at the power density of 1.45 J/cm$^2$ The n-MOSFETs fabricated on laser activated p-well exhibit well-behaved I-V characteristics and threshold voltage reduction by reverse body voltage. These results prove that the laser process for implant activation is an alternative low temperature technology applicable to SiC devices.

• Journal of the Korean Vacuum Society
• /
• v.14 no.2
• /
• pp.97-102
• /
• 2005

NO adsorption can be used in synthesizing oxynitride thin films which have potential application in nanodevices. However, it is very difficult to understand the oxynitridation Process since too many factors are involved in it. In this paper, we present our first-principles molecular dynamics calculation of the NO molecule adsorption on the Si(001) surface as the initial stage of the oxynitridation process. The previous first-principles calculation has argued the NO molecule is dissociated with a very small activation barrier, 0.07eV, which acutally corresponds to 1.60eV considering thermodynamics. This is in clear contrast to the observation that NO is dissociated at temperatures as low as 20K From extensive searches of NO on the Si(001) surface, we have found the new dissociation processes that have the much lower activation energies, less than 0.01 eV. We also present the dissociation and penetration processes with the corresponding activation energies and discuss their experimental implications.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2002.08a
• /
• pp.177-180
• /
• 2002

Microwave has been utilized for low-temperature crystallization of amorphous Si films. Microwave annealing lowered the crystallization temperature and shortened the annealing time. The combination of Ni and microwave applications on a-Si films further enhanced the crystallization. The enhancement was due to both reduced nucleation activation energy and growth activation energy.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.752-755
• /
• 2006

Reverse annealing was observed in $P^+/B^+$ ion shower doped poly-Si upon activation annealing. Phosphorous or boron was implanted by ion shower doping using a source gas mixture of $PH_3/H_2$ or $B_2H_6/H_2$. Activation annealing was conducted using a tube furnace in the temperature ranges from $350^{\circ}C$ to $650^{\circ}C$. Hall measurement revealed that reverse annealing begins at different annealing temperatures for poly-Si implanted with P and B, respectively. It was observed that reverse annealing starts at $550^{\circ}C$$ in $P^+$ ion shower doped poly-Si, while at $350^{\circ}C$ in the case of B-doping.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.95-97
• /
• 2004

We studied a low temperature ion doping process for poly-Si Thin Film Transistor (TFT) on plastic substrates. The ion doping process was performed using an ion shower system, and subsequently, excimer laser annealing (ELA) was done for the activation. We have studied the crystallinity of Si surface at each step using UV-reflectance spectroscopy and the sheet resistance using 4-point probe. We found that the temperature has increased during ion shower doping for a-Si film and the activation has not been fulfilled stably because of the thermal damage against the plastic substrate. By trying newly a pulsed ion shower doping, the ion was efficiently incorporated into the a-Si film on plastic substrate. The sheet resistance decreased with the increase of the pulsed doping time, which was corresponded to the incorporated dose. Also we confirmed a relationship between the crystallinity and the sheet resistance. A sheet resistance of 300 ${\Omega}$/sq for the Si film of 50nm thickness was obtained with a good reproducibility. The ion shower technique is a promising doping technique for ultra low temperature poly-Si TFTs on plastic substrates as well as those on glass substrates.

• Journal of the Korean institute of surface engineering
• /
• v.12 no.2
• /
• pp.75-83
• /
• 1979

The Rates of formation and heats of activation for the intermatallic Compound Layers between Cold rolled sheet and molten aluminium &ath (adding small amounts of silicon) has been determined by Continous aluminizing method in the temperature range of 680$^{\circ}$ to 760$^{\circ}C$ and with immerssion time. The structure of the intermetallic Compound Layers was the shape of "Tongues" in pure Al-Bath and Al-Bath Containing 1% Si, But in Al-5% Si Bath was "Band" the Composition of the intermetallic Compound Layers were checked by microhardness measurements and X-Ray probe micro analyzer. FeAl intermetallic Compound layer was found to be uniform in pure Al-Bath and Al-5% Si Bath, But Fe Al intermetallic Compound Layer was shown in Al-1% Si Bath. The growth Rates of the intermetallic Compound Layers was most rapidly increased at Temperatures from 720$^{\circ}$ to 760$^{\circ}C$, at the immorsion time above 60 Second in pure Al-Bath, But in Al-1% Si Bath was solwly increased for the same conditions, and then in Al-5% Si Bath was hardly effected by these experimental condition. Heasts of activation of 29, 46 Kcal per mole which calculuted from Layer growth experiments were found in pure Al-Bath, Al-1% Si Bath respectively.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1999.07a
• /
• pp.63-63
• /
• 1999

The stability of hydrogenated amorphous silicon (a-Si:H) films under the light soaking are very important since the applications of a-Si:H films are solar cells, color sensors, photosensors, and thin film transistors(TFTs). We found the changes of the electric conductivity and the conductivity activation energy (Ea) of a-Si:H films by argon radical annealing. The deposition rate of a-Si:H films depends on the argon radical annealing time. The optical band gap and the hydrogen contents in the a-Si:H films are changes along the argon radical annealing time. We will discuss the microscopic processes of argon radical annealing in a-si:H films.