• Textile Coloration and Finishing
• /
• v.8 no.6
• /
• pp.33-39
• /
• 1996

The purpose of this study was to investigate the structural characteristics, mechanical properties, and stress-relaxation behavior of PET filament, which were prepared at various spinning speeds(1650, 3300, 4500, 5000, 5500, and 6000 m/min) and anneal(12$0^{\circ}C$, 20 min & 15$0^{\circ}C$, 40 min). In 4500 m/min of spinning speed the crystallinity, crystallite size, and degree of orientation of PET filament rapidly increased. By increasing spinning speed, the temperature dependence of stress-relaxation sharply decreased. Same results were obtained from heat-treated samples. As a result, activation energy for stress-relaxation increased with the crystallinity and spinning speed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.4
• /
• pp.294-297
• /
• 2012

In this work, local oxidation behavior in phosphorous ion-implanted 4H-SiC has been investigated by using atomic force microscopy (AFM). The AFM-local oxidation (AFM-LO) has been performed on the implanted samples, with and without activation anneal, using an applied bias (~25 V). It has been clearly shown that the post-implantation annealing process at $1,650^{\circ}C$ has a great impact on the local oxidation rate by electrically activating the dopants and by modulating the surface roughness. In addition, the composition of resulting oxides changes depending on the doping level of SiC surfaces.

• Nuclear Engineering and Technology
• /
• v.22 no.4
• /
• pp.337-350
• /
• 1990

A post-irradiation annealing study was conducted with use of reactor pressure vessel(RPV) steel A533B Cl.1 base metal irradiated to a dose of 4.84$\times$10$^{18}$ n/$\textrm{cm}^2$ at about 38$0^{\circ}C$. Microhardness and positron annihilation (PA) methods were used to obtain better understanding of the recovery of radiation hardening. Isochronal anneal experiments indicated that two recovery processes occur during annealing of irradiated specimens. The first recovery process occurs in the temperature range of 280-3O5$^{\circ}C$, Michrohardness and positron annihilation (PA) methods were used to obtain better understanding of the recovery of radiation hardening. Isochronal anneal experiments indicated that two recovery processes occur during annealing of irradiated specimens. The first recovery process occurrs in the temperature range of 280-305$^{\circ}C$. The variations of Ip, Iw and R parameters indicated that the formation of vacancy clusters by vacancy agglomeration and the annihilation of monovacancies are the first recovery process. The second recovery process occurs in the range of 405-49$0^{\circ}C$ and positron annihilation parameters measured indicated that the dissolution of carbon atoms decorated around vacancy-type defects and possible precipitates, and the annihilation of monovacancies give rise to the second recovery process. It was further indicated that radiation anneal hardening (RAH) in the range of 305-405$^{\circ}C$ between the temperature ranges for the two processes occurs due to the formation of carbon-decorated vacancy clusters and precipitates. The activation energies, orders of reaction and other characteristics of recovery processes were determined by the Meechan-Brinkman method. The activation energy for the first recovery process was determined as 1.76 eV and that for the second recovery process as 2.00eV. These values are lower than those obtained by other workers. This difference may be attributed to the lower copper content of the RPV steel used in the present study. The order of reaction for the first recovery process was determined as 1.78, while that for the second recovery process as 1.67 Non-integer orders of reaction for recovery processes seem to be attributed to the fact that several mechanisms for the first order and the second order of reaction are compounded in one process. This result also supports for the above conclusions from measurements of PA parameters.

• Korean Journal of Materials Research
• /
• v.1 no.1
• /
• pp.23-28
• /
• 1991

The resistivity of polycrystalline silicon film deposited by low pressure chemical vapor deposition and doped by arsenic Implantation has been investigated as a function of dopant concentration and testing temperature ranging from $25^{\circ}C$ to $105^{\circ}C$ . The resistivity vs. doping concentration curve had a peak point with highest activation energy with respect to the dependence of the resistivity on temperature. We showed that $O_2$ plasma anneal followed by heat-treatment in $N_2$ ambient was able to recover the resistivity degraded by the plasma deposited passivation layers.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.3 no.1
• /
• pp.13-20
• /
• 2003

Both MgO and $Sc_2O_3$ are shown to provide low interface state densities (in the $10^{11}{\;}eV^{-1}{\;}cm{\;}^{-2}$ range)on n-and p-GaN, making them useful for gate dielectrics for metal-oxide semiconductor(MOS) devices and also as surface passivation layers to mitigate current collapse in GaN/AlGaN high electron mobility transistors(HEMTs).Clear evidence of inversion has been demonstrated in gate-controlled MOS p-GaN diodes using both types of oxide. Charge pumping measurements on diodes undergoing a high temperature implant activation anneal show a total surface state density of $~3{\;}{\times}{\;}10^{12}{\;}cm^{-2}$. On HEMT structures, both oxides provide effective passivation of surface states and these devices show improved output power. The MgO/GaN structures are also found to be quite radiation-resistant, making them attractive for satellite and terrestrial communication systems requiring a high tolerance to high energy(40MeV) protons.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.47 no.4
• /
• pp.13-19
• /
• 2010

MOSFET with deuterium-incorporated gate oxide shows enhanced reliability compared to conventional MOSFET. We present an alternative process whereby deuterium is delivered to the location where the gate oxide reside by an implantation process. Deuterium ions were implanted using two different energies to account for the topography of the overlaying layers and placing the D peak at the top of gate oxide. A short anneal at forming gas was performed to remove the D-implantation damage. We have observed that deuterium ion implantation into the gate oxide region can successfully remove the interface states and the bulk defects. But the energy and the dose of the deuterium implant need to be optimized to maintain the Si substrates dopant activation, while generating deuterium bonds inside gate oxide. CV and IV characteristics studies also determined that the deuterium implant dose not degrade the transistor performance.

• Transactions on Electrical and Electronic Materials
• /
• v.9 no.1
• /
• pp.6-11
• /
• 2008

In this study, we investigated effects of hydrogen annealing (HA) and plasma nitridation (PN) applied in order to improve $Si/SiO_2$ interface characteristics of TiN metal gate. In result, HA and PN showed a positive effect decreasing number of interface state $(N_{it})$ respectively. After FN stress for verifying reliability, however, we identified rapid increase of $N_{it}$ for TiN gate with HA, which is attributed to hydrogen related to a change of $Si/SiO_2$ interface characteristic. In contrast to HA, PN showed an improved Nit and gate oxide leakage characteristic due to several possible effects, such as blocking of Chlorine (Cl) diffusion and prevention of thermal reaction between TiN and $SiO_2$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.11
• /
• pp.968-972
• /
• 2008

Ni/Ti/Al multilayer system ('/'denotes the deposition sequence) was tested for low-resistance ohmic contact formation to Al-implanted p-type 4H-SiC. Ni 30 nm / Ti 50 nm / Al 300 nm layers were sequentially deposited by e-beam evaporation on the 4H-SiC samples which were implanted with Al (norminal doping concentration = $4\times10^{19}cm^{-3}$) and then annealed at $1700^{\circ}C$ for dopant activation. Rapid thermal anneal (RTA) temperature for ohmic contact formation was varied in the range of $840\sim930^{\circ}C$. Specific contact resistances were extracted from the measured current vs. voltage (I-V) data of linear- and circular transfer length method (TLM) patterns. In constrast to Ni contact, Ni/Ti/Al contact shows perfectly linear I-V characteristics, and possesses much lower contact resistance of about $2\sim3\times10^{-4}\Omega{\cdot}cm^2$ even after low-temperature RTA at $840^{\circ}C$, which is about 2 orders of magnitude smaller than that of Ni contact. Therefore, it was shown that RTA temperature for ohmic contact formation can be lowered to at least $840^{\circ}C$ without significant compromise of contact resistance. X-ray diffraction (XRD) analysis indicated the existence of intermetallic compounds of Ni and Al as well as $NiSi_{1-x}$, but characteristic peaks of $Ti_{3}SiC_2$, a probable narrow-gap interfacial alloy responsible for low-resistance Ti/Al ohmic contact formation, were not detected. Therefore, Al in-diffusion into SiC surface region is considered to be the dominant mechanism of improvement in conduction behavior of Ni/Ti/Al contact.

• Korean Journal of Materials Research
• /
• v.5 no.1
• /
• pp.42-54
• /
• 1995

$Ta_2O_5$ thin film IS a promising material for the high dielectrics of ULSI DRAM. In this study, $Ta_2O_5$ thin film was grown on p-type( 100) Si wafer by thermal metal organic chemical vapo deposition ( MCCVD) method and the effect of operating varialbles including substrate temperature( $T_s$), bubbler temperature( $T_ \sigma$), reactor pressure( P ) was investigated in detail. $Ta_2O_5$ thin film were analyzed by SEM, XRD, XPS, FT-IR, AES, TEM and AFM. In addition, the effect of various anneal methods was examined and compared. Anneal methods were furnace annealing( FA) and rapid thermal annealing( RTA) in $N_{2}$ or $O_{2}$ ambients. Growth rate was evidently classified into two different regimes. : (1) surface reaction rate-limited reglme in the range of $T_s$=300 ~ $400 ^{\circ}C$ and (2: mass transport-limited regime in the range of $T_s$=400 ~ $450^{\circ}C$.It was found that the effective activation energies were 18.46kcal/mol and 1.9kcal/mol, respectively. As the bubbler temperature increases, the growth rate became maximum at $T_ \sigma$=$140^{\circ}C$. With increasing pressure, the growth rate became maximum at P=3torr but the refractive index which is close to the bulk value of 2.1 was obtained in the range of 0.1 ~ 1 torr. Good step coverage of 85. 71% was obtained at $T_s$=$400 ^{\circ}C$ and sticking coefficient was 0.06 by comparison with Monte Carlo simulation result. From the results of AES, FT-IR and E M , the degree of SiO, formation at the interface between Si and TazO, was larger in the order of FA-$O_{2}$ > RTA-$O_{2}$, FA-$N_{2}$ > RTA-$N_{2}$. However, the $N_{2}$ ambient annealing resulted in more severe Weficiency in the $Ta_2O_5$ thin film than the TEX>$O_{2}$ ambient.