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We developed a slim double-skin window (SDSW) with the aim of reducing building energy consumption for heating and cooling, thereby reducing the impact of buildings on climate change. The developed SDSW is a slim structure with an air cavity thickness of 20 mm, i.e., thinner than that of a traditional double-skin facade (DSF). We analyzed changes in the thermal properties and cooling and heating energy consumption of the SDSW as well as the effects of the thin air cavity on window performance. A testbed was constructed to analyze the seasonal temperature properties of the glass and the cooling and heating energy consumption. We also compared the long-term effects of the air cavity on the difference between outdoor and indoor glass surface temperatures under similar conditions for the SDSW and traditional DSF. The SDSW temperature was 3 °C lower than that of the traditional DSF, and the cooling and heating energy consumption dropped by 6.5%. Although the performance of the developed SDSW was comparable to that of traditional DSF, the life-cycle cost was reduced by 47%.

Traditional anti-reflective (AR) coating films prepared using tetraethylorthosilicate (TEOS) as a precursor absorbs water easily in addition to having a weak abrasion resistance. To improve the transmittance, hydrophobicity and abrasion resistance of AR coating film, various AR coating films were prepared using methyltrimethoxysilane (MTMS) as a precursor in addition to in- troducing a fluoroalkylsilane, acid catalyst, base catalyst and acid-base two step catalyst. The prepared AR coating films were then characterized by UV-Vis spectroscopy, contact angle analyzer, atomic force microscope (AFM), pencil scratch hardness test and cross-cut test. As a result, the transmittance of bare glass was 90.5%, while that of AR coating glass increased to 94.8% at curing temperature of 300 ℃. When the fluoroalkylsilane was added, the water contact angle of AR coating film increased from 96.3° to 108°, indicating that the hydrophobicity of the film was greatly improved. The abrasion resistance of AR coating film was also improved by the acid catalyst, whereas the transmittance increased by the base catalyst. In the case of AR coating film prepared using an acid-base two step catalyzed reaction, both the transmittance and abrasion resistance of the film was synergistically enhanced as compared with those of AR coating films prepared without introduction of a catalyst.

The stress corrosion cracking (SCC) behavior of Fe18Cr10Mn1Ni(0.3–0.8)N alloys was investigated in aqueous NaCl environment by using slow strain rate test method, and the results were compared to those of Ni-free counterparts. The addition of N tended to improve the SCC resistance of Fe18Cr10Mn- and Fe18Cr10Mn1Ni-based alloys. The alloying Ni magnified the beneficial effect of N on the SCC susceptibility and, eventually, the Fe18Cr10Mn0.8N alloy was immune to SCC in 2 M NaCl solution at 50 °C. The SCC behavior of the present alloys was found to be closely related to the repassivation tendency and the resistance to pitting corrosion.

The sensitization and intergranular corrosion associated with a phase transformation of tube-to-tubesheet welds of hyper duplex stainless steel were investigated using modified double loop electrochemical potentiokinetic reactivation. The susceptibility to sensitization of the hyper duplex stainless steel tube-to-tubesheet welded with an Ar shielding gas supplemented with nitrogen gas decreased owing to a decrease of the ferrite phase fraction and precipitation of chromium nitrides, thereby increasing the intergranular corrosion resistance. The intergranular corrosion in the hyper duplex stainless steel welds was selectively initiated at the Cr-depleted regions adjacent to the chromium nitride precipitates in the ferrite phases.

* School of Mechanical Engineering, Pusan Nat’l Univ. (Received November 16, 2013 ; Revised January 22, 2014 ; Accepted January 22, 2014)Key Words: Contact Angle(접촉각), Contact Line(접촉선), Droplet(액적), Neighbor Frequency(주변부 주파수), Resonance Frequency(공진 주파수), Secondary Droplet(미소 액적), Shape Oscillation (형상 진동), Waggling Motion (좌우 흔들림)초록: 본 연구는 주기적 강제 진동이 가해지는 표면의 액적 모드 특성과 표면에 놓인 액적의 제거에 대한 조건을 실험적으로 이해하는 것을 목적으로 하고 있다. 액적의 거동을 명확하게 관찰하기 위해 아크릴 표면에 Teflon 코팅을 진행하여 접촉각을 높였고, 히스테리시스는 25도 이내로 진행하여 액적의 거동이 보다 쉽게 진행되도록 하였다. 본 실험은 먼지가 적은 청정실에서 실험이 진행되었다. 제작된 소수성 표면에 놓인 액적의 실제 공진 주파수를 예측하기 위해 이론 및 실험적 해석을 통해 두 접근방법의 타당성을 파악하였으며, 두 개의 초고속카메라를 액적의 상면과 측면에 설치하여 2가지 측면에서 액적의 다양한 형상 변형 특성- 모드 형상, 분리, 미소 액적의 발생, 그리고 좌우 비틀림의 특성을 관찰하였다. 이론 값 비교결과 실제 공진 주파수 값들의 차이가 약 18% 이하로 관찰되었으며, 이러한 차이는 접촉선 마찰, 비선형 벽 고착, 실험의 불확실성 등에 가장 큰 영향을 받는 것으로 판단된다. 사용된 스피커에 상대적으로 낮은 전압을 인가할 경우 액적의 접촉선은 고정된 상태에서 좌우 대칭적인 액적 형상진동이 나타났다. 반면, 높은 전압을 인가할 경우 액적의 접촉선은 비고정된 상태가 되면서 더 활발한 형상 진동이 나타났다. 가진 주파수가 모드 주파수와 일치할 경우에는 액적의 로브 크기가 주변부 주파수 일 때 보다 비교적으로 컸으며, 같은 전압을 인가 할 경우, 표면에 놓인 액적의 미소 액적 발생 및 완전한 제거는 2차 모드에서만 진행되는 것을 실험을 통해 규명하였다.Abstract: This study aimed to understand the mode characteristics of a droplet subject to periodic forced vibration and the detachment of a droplet placed on a plate surface. An surface was coated with Teflon to clearly observe the behavior of a droplet. The contact angle between the droplet and surface and the hysteresis were found to be approximately 115° and within 25°, respectively. The coating process was performed in a clean room that had an environment with a low level of contaminants and impurities such as air dust, detergents, and particles. To predict the resonance frequency of a droplet, theoretical and experimental approaches were applied. Two high-speed cameras were configured to acquire side and top views and thus capture different characteristics of a droplet: the mode shape, the detachment, the separated secondary droplet, and the waggling motion. A comparison of the theoretical and experimental results shows no more than 18 discrepancies when predicting the resonance frequency. These differences seem to be caused by contact line friction, nonlinear wall adhesion, and the uncertainty of the experiment. For lower energy inputs, the contact line of the droplet was pinned and the oscillation pattern was axisymmetric. However, the contact line of the droplet was de-pinned as the oscillation became more vigorous with increased energy input. The size of each lobe at the resonance frequency is somewhat larger than that at the neighboring frequency. A droplet in mode 2, one of the primary mode frequencies, exhibits vertical periodic movement as well as detachment and secondary ejection from the main droplet.

* School of Mechanical Engineering, Pusan Nat’l Univ.(Received November 13, 2013 ; Revised February 4, 2014 ; Accepted February 4, 2014)Key Words: Hydrophobic Surface(소수성 표면), Deionized Water(탈이온수), Flow Visualization(유동가시화), Contact Angle(접촉각), Resonance Frequency(공진 주파수), Lobe(둥근 돌출부)초록: 본 연구의 목표는 주기적으로 강제 진동하는 소수성 표면위에 놓인 액적의 내부유동 특성을 이해하는 것이다. 액적의 공진주파수를 예측하기 위해서 고속카메라와 매크로렌즈를 사용하여 진동하는 소수성 표면위의 액적의 내부유동 특성을 확인하였다. 그 결과 특정 모드에서의 액적은 다양한 형상을 갖고 있으며 또한, 각각의 액적 내부에서 와류가 관찰 되었다. 일반적으로 유동흐름이 대칭축을 따라 위로 이동하고 액적상단에서 표면을 따라 접촉선부근으로 이동하였다. 반면에 모드 6과 모드 8에서는 아주 큰 와류가 생성되었다. 또한 유동속도가 모드 2보다 모드 4에서 더 빠르고 반면에 모드 6와 모드 8은 거의 비슷하였다.Abstract: This study aimed to understand the internal flow characteristics of a liquid droplet subject to periodic forced vibration. In order to predict the resonance frequency of a droplet, a high-speed camera and macro lens were used to capture internal flow characteristics of a droplet placed on a vibrating hydrophobic surface. Results showed that the droplet assumed a variety of shapes depending on the resonance mode of free droplet, particularly in modes 2, 4, 6, and 8. In addition, the induced internal vortex flow inside the droplet was also observed in each mode. Typically, the induced flow moved upwards along the axis of symmetry and downwards along the surface of the droplet, that is, from the apex to the contact line in modes 2 and 4, after which it broke into a smaller vortex. On the other hand, the large-scale vortex always remained steady in modes 6 and 8. The speed of the flow in mode 4 was always greater than that in mode 2, but those in modes 6 and 8 were similar.

Stress corrosion cracking (SCC) susceptibility of austenitic Fe18Cr10Mn alloys with 0.3N, 0.6N and 0.3N0.3C was investigated in aqueous chloride environment using a slow strain rate test method. The SCC susceptibility of Fe18Cr10Mn alloys in 2 M NaCl solution at 50 °C under constant anodic potential condition decreased with increase in N content from 0.3 to 0.6 wt%, and with addition of 0.3 wt% C to the Fe18Cr10Mn0.3N alloys. The present study strongly suggested that the beneficial effects of N and C on the SCC behavior of Fe18Cr10Mn alloys would be associated with the resistance to pitting corrosion initiation and the repassivation kinetics.

Optical devices are used extensively in the field of information network. Increasing demand for optical device, optical interconnection has been a important issue for commercialization. However many problems exist in the interconnection between optical device and optical fiber, and in the case of the multi-channel, problems of the optical alignment and optical array arise. For solving the alignment and array problem of optical device and the optical fiber, we fabricated fiber alignment and array by using imprint technology. Achieved higher precision of optical fiber alignment and array due to fabricating using imprint technology. The silicon stamp with different depth was fabricated using the conventional photolithography. Using the silicon stamp, a nickel stamp was fabricated by electroforming process. We conducted imprint process using the nickel stamp with different depth. The optical alignment and array by fabricating the patterns of optical device and fiber alignment and array using imprint process, and achieved higher precision of decreasing the dimensional error of the patterns by optimization of process. The fabricated optical interconnection of PLC device was measured 3.9 dB and 4.2 dB, lower than criteria specified by international standard.

The effects of shielding gas on the microstructure and localized corrosion of tube-to-tube sheet welds of SR-50A super austenitic stainless steel for seawater cooled condense were investigated in highly concentrated chloride environments. The localized corrosion resistance of the weld metal after welding with an Ar shielding gas supplemented with N 2 increased due to a decrease in the pitting resistance equivalent number (PREN) difference between the PREN IR of interdendritic region and the PREN DC of dendrite core. The localized corrosion was selectively initiated at the dendrite core because the PREN of the dendrite core was smaller than that of the interdendritic region.

To improve fire-resistance of a high strength concrete against spalling under elevated temperature, fibers can be mixed to provide flow paths of evaporated water to the surface of concrete when heated. In this study, the experiment of a column under fire and mechanical loads is conducted and the material model for predicting temperature of reinforcement steel bar and mechanical behavior of fiber-mixed high strength concrete is suggested. The material model in previous studies is modified by incorporating physical behavior of internal concrete and thermal characteristics of concrete at the elevated temperature. Thermo-mechanical analysis of the fiber-mixed high strength concrete column is conducted using the calibrated material model. The performance of the proposed material model is confirmed by comparing thermo-mechanical analysis results with the experiment of a column under fire and mechanical loads.

To improve fire-resistance of a high strength concrete against explosive spalling under elevated temperature, fibers can be mixed with concrete to provide flow paths of evaporated water within concrete to the free surface. The fiber-mix concrete approach is effective against explosive spalling when the flow path generated from melting fibers at the elevated temperature is interconnected to transport high pressurized evaporated water from the inside concrete to the free surface. The percolation theory can identify the connectivity of the fibers and provide an estimate of the fire-resistance of concrete by investigating layout of fibers. In this study, the correlation between percolation theory and explosive spalling of fiber-mixed high strength concrete is analyzed and the connectivity of the fiber in concrete is stereologically investigated by using virtual specimens of fiber-mixed high strength concrete.

The behaviors of localized corrosion associated with microstructure of tube-to-tube sheet welds of UNS S32050 super austenitic stainless steel for seawater cooled condenser were investigated in highly concentrated chloride environments. In the interdendritic region, Cr and Mo as α-stabilizers were enriched and N as the γ-stabilizer was depleted whereas in the dendrite core, Cr and Mo were depleted and N was enriched. Based on the PRENIR and PRENDC values, the localized corrosion was selectively initiated at the dendrite core (DC) because the PREN value of the dendrite core was much smaller than that of the interdendritic region (IR). It was found that the resistance to localized corrosion of the UNS S32050 SASS tube-to-tube sheet welds at least as good as that of a UNS S31254 SASS base metal with PREN 47 in highly acidified chloride environments.

Attrition of zinc-titanate sorbent particles were measured in a fluidized bed at a condition that attrition by gas jets of a distributor was dominant. Abrasion was found to govern the attrition of present sorbent particles. The top size of particles produced by attrition and the attrition rate increased with an increase of static bed height when the static bed height was less than jet penetration length of the distributor. However, the top size of produced particles and the attrition rate decreased with increasing static bed height when the static bed height was greater than jet penetration length of the distributor. Maximum values of the top size of produced particles and the attrition rate were found at a static bed height corresponding to a jet penetration length of the distributor. The top size of produced particles and the attrition rate increased with increasing relative humidity or gas velocity, whereas with decreasing temperature.

Vertical diodes for cross-point phase change memory were realized by selective epitaxial growth (SEG) technique using cyclic chemical vapor deposition method. H2/SiH4/Cl2 cyclic CVD system was introduced in batch-type vertical furnace equipement, replacing conventional single-wafer H2/dichlorosilane/HCl CVD system. It provided excellent capacity of 40 wafers per batch. Selectivity loss which is one of the most crucial features in SEG process for diode application was controlled with both the amount of SiH4 and Cl2 and the period of gas supply, and practical value of selectivity loss was confirmed to be less than 100 in 200-mm wafers. Structural and electrical properties of pn diodes were investigated, and cyclic SEG silicon diode showed more eligible electrical ability to current flow than that of poly-si in terms of forward current and ideality factor as well as lower reverse leakage current.

This study examined whether palm cooling (PC) could reduce heat strain, measured through changes in core, mean skin, mean body temperatures, and thermal sensation in resting hyperthermic subjects wearing chemical protective garments. Ten male subjects performed three exercise bouts (6.1 km h(-1), 2-4% grade) in a hot, dry environment [mean (SD) air temperature 42.2 (0.5 degrees C), relative humidity 36.5 (1%)] until core temperature reached 38.8 degrees C. Subjects then simulated transport in an armoured vehicle by resting in a seated position for 50 min with either no cooling (NC), (PC at 10 degrees C) or palm cooling with vacuum application around the hand (PCVAC, 10 degrees C, 7.47 kPa negative pressure). Core, skin, and mean body temperatures with PC and PCVAC were lower (P0.05) than NC from 15 to 50 min of cooling, and thermal sensation was lower (P0.05) from 30 to 50 min, with no differences in any variables between PC and PCVAC. Maximal heat extraction averaged 42 (12 W), and core temperature was reduced by 0.38 (0.21 degrees C) after 50 min of PC. Heat extraction with PC was modest compared to other cooling approaches in the literature.

Recently, fiber-reinforced plastic(FRP) wraps are blown as an effective material for the enhancement and rehabilitation of aged concrete structures. The purpose of this investigation is to experimentally investigate behavior of concrete cylinder wrapped with FRP materials. Experimental parameters include compressive strength of concrete cylinder, FRP material, and confinement ratio. This paper presents the results of experimental studies on the performance of concrete cylinder specimens externally wrapped with aramid, carbon and glass fiber reinforced Polymer sheets. Test specimens were loaded in uniaxial compression. Axial load, axial and lateral strains were investigated to evaluate the stress-strain behavior, ultimate strength ultimate strain etc. Test results showed that the concrete strength and confinement ratio, defined as the ratio of transverse confinement stress and transverse strain were the most influential factors affecting the stress-strain behavior of confined concrete. More FRP layers showed the better confinement by increasing the compressive strength of test cylinders. In case of test cylinders with higher compressive strength, FRP wraps increased the compressive strength but decreased the compressive sham of concrete test cylinders, that resulted in prominent brittle failure mode. The failure of confined concrete was induced by the rupture of FRP material at the stain, being much smaller than the ultimate strain of FRP material.

Germanium (Ge) ion implantation was investigated for crystallinity enhancement during solid phase epitaxial (SPE) regrowth. Electron back-scatter diffraction (EBSD) measurement showed numerical increase of 19% of (100) signal, which might be due to the effect of pre-amorphization implantation (PAI) on silicon layer. On the other hand, electrical property such as off-leakage current of n-channel metal oxide semiconductor (NMOS) transistor degraded in specific regions of wafers. It was confirmed that arsenic (As) atoms were incorporated into channel area during Ge ion implantation. Since the equipment for Ge PAI was using several source gases such as BF3 and AsH3, atomic mass unit (AMU) contamination during PAI of Ge with AMU 74 caused the incorporation of As with AMU 75 which resided in arc-chamber and other parts of the equipment. It was effective to use Ge isotope of AMU 72 to suppress AMU contamination. It was effective to use enriched Ge source gas with AMU 72 in order to improve productivity.

Since layup orientation of the laminates greatly influences its properties, an NDE technique for layup orientation determination would be very beneficial. It is desirable to perform contact-less nondestructive evaluation to assess material properties and defects of composites because of permeation of coupling medium such as water. An ultrasonic technique would be very useful, which could be used to test the part after and before curing laminates and requires less time than the optical test. First of all, conventional ultrasonic experimentations were conducted using water as a transmitting medium. In contrast, air-coupled ultrasound is non-contact and has clear advantages over water-coupled testing. Therefore ultrasonic systems for air-coupled and conventional ultrasound were set out for different measurement modalities for acquiring ultrasonic signals as a function of in-plane azimuthal angle. Firstly, a manual scanner was built for making transmission measurements using a pair of normal-incidence shear wave transducers to find the effect of fiber misorientations of orthotropic composite laminates. With the transmitter and receiver on the same side of a laminates, Lamb waves were generated and used for the amplitude magnitude. As a result, it was confirmed that the influence of fiber direction in the laminates could be detected by the non-contacting or contacting inspection from one-side and the detectability was improved by using shaped tube for reducing the specular reflection on transmitting. Furthermore, a vector decomposition model was utilized for lay-up error of the orthotropic laminates. Finally, aircoupled results well corresponded somewhat to those of contact ultrasonic examination in the orthotropic laminates.

A nondestructive technique would be very beneficial, which could be used to test the part before (uncured) and after curing CF/Epoxy. A new method for nondestructively determining the ply layup in a composite laminate is presented. The method employs a normal-incidence longitudinal ultrasound to perform C-scan of ply interfaces of the laminate, and extracts fiber orientation information from the ultrasonic reflection in the laminate. Using two-dimensional spatial Fourier transform, interface C-scan images were transformed into quantitatively angular distribution plots to show the fiber orientation information therein and to determine the orientation of the ply. In order to develop these methods into practical inspection tools, an automated system using a motor has been developed for different measurement modalities for acquiring ultrasonic effects of ply-layup error. Therefore, it is found that the efficiency of developed system shows between the practical testing and model in characterizing cured/uncured ply-layup error of the laminates. A C-scan image of a ply interface seem to have the ply-layup error information of the two neighboring plies of CF/Epoxy composite laminates.

In this work, MOS capacitors were used to study the electrical properties of Mo gate electrode deposited on ZrO. The workfunctions of Mo gate extracted from C-V curves were appropriate for PMOS. Thermal stability of Mo metal was investigated by analyzing the variations of workfunction and EOT(effective oxide thickness) after 600, 700, and 800 RTA(rapid thermal annealing). It was found that Mo gate was stable up to 800 with underlying ZrO. The resistivities of Mo were 35Ωcm∼ 75Ωcm. These values are lower than those of heavily doped polysilicon. Based on these measurements, it can be concluded that Mo metal gate with ZrO gate insulator is an excellent gate material for PMOS.

A mathematical model has been developed to predict the performance of a continuous bubblingfluidized-bed hot-gas desulfurization system in the integrated gasification combined cycle. For both the bubbling-fluidized-bed desulfurizer and the bubbling-fluidized-bed regenerator, the model combines the particle residence time with the kinetic rate in each reactor. The flow pattern of the solid phase was assumed to be well-mixed, and the flow pattern of the gas phase was assumed to be plug flow. The model has been applied to Korea Institute of Energy Research’s laboratory-scale fluidized-bed process. The present model provides a reasonable fit in predicting the experimental result that the outlet concentration of H2S increased nearly proportionally to the inlet concentration of H2S in the desulfurizer. The sulfur concentration in both the desulfurizer and the regenerator was predicted to increase exponentially as the inlet concentration of H2S increased in the desulfurizer. The outlet concentration of H2S was predicted to decrease exponentially in the desulfurizer as the static bed height increased in both the desulfurizer and the regenerator. The outlet concentration of H2S was predicted to increase exponentially in the desulfurizer as the gas velocity increased in both the desulfurizer and the regenerator.

This paper describes the characteristics of Ru-Zr alloy gate electrodes deposited by co-sputtering. The various atomic composition was made possible by controlling sputtering power of Ru and Zr. Thermal stability was examined through 600 and 700 RTA annealing. Variation of oxide thickness and X-ray diffraction(XRD) pattern after annealing were employed to determine the reaction at interface. Low and relatively stable sheet resistances were observed for Ru-Zr alloy after annealing. Electrical properties of alloy film were measured from MOS capacitor and specific atomic composition of Zr and Ru was found to yield compatible work function for nMOS. Ru-Zr alloy was stable up to while maintaining appropriate work function and oxide thickness.

Polycaprolactone (PCL) has been blended with thermoplastic starch (TPS), prepared from regular corn starch and glycerol, in a twin-screw extruder. The rheological, mechanical, thermal and morphological properties of the blends were examined. Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM) studies revealed that PCL/TPS blends are thermodynamically immiscible. However, they form compatible blends as a result of the hydrogen bonding interaction between the ester carbonyl of PCL and the OH groups on starch. Biodegradability of the blends increased with increasing TPS content. Dynamic viscoelastic measurements concluded that blends containing above 60-wt% TPS had higher storage and loss moduli than those of pure TPS and PCL. In addition, these blends had higher complex viscosities. Polym. Eng. Sci. 44:1429–1438, 2004. © 2004 Society of Plastics Engineers.

In this study, we obtain experimental understanding of the mode characteristics of a droplet placed on a flat surface under periodic forced vibrations. The detachment conditions for the droplet on the surface were also studied. In order to estimate the resonance frequency of a droplet placed on a hydrophobic surface, theoretical modelling was combined with experimental approaches. Two high speed cameras were used to observe droplet characteristics, including mode shape, detachment, occurrence of secondary droplet breakup, and horizontal torsional motion. Two cameras were installed to the right above the droplet and at the side of the droplet. There was no more than an 18% discrepancy between the theoretical and experimental resonance frequencies. This discrepancy was likely caused by several factors such as contact line friction, nonlinear wall adhesion, and experimental uncertainty. When applying a relatively low voltage to a speaker, the contact line of a droplet was pinned and shape oscillations of the droplet appeared in a bilaterally symmetric way. In contrast, at higher voltages, the contact line depinned and the shape oscillations became more active. For excitation frequencies identical to the mode frequency, the lobe size of the droplet was relatively larger than that at neighbouring frequencies. The experimental results also indicate that the generation and complete detachment of small-scale droplets occur only at the 2nd mode.

The objective of this research is the optimization of energy parameters such as the temperature and flow rate of the fluid in heat exchangers in the gasification system in order to increase the recovery rate of energy in the system. A mathematical model of these heat exchangers is developed to predict their operating performance under the specified gasification system. The optimal flow rate and temperature of the fluid in the heat exchanger based on the effectiveness - number of transfer units(NTU) method is investigated. The result of the simulation shows that the optimal mass flow rate and temperature of the high pressure (HP) boiler feed water are determined at 175,907 kg/h and 110°C, respectively, while the optimal mass flow rate and temperature of high pressure saturated steam of boiler are determined at 238,430 kg/h, 290.5°C, respectively. At these values, the total heat amount obtained at these heat exchangers is highest with 169 MW. Besides, the total heat amount obtained at heat exchangers could be increased by 4.61% (7.8 MW) when sixty percent of the heat release amount from air cooler (12.78 MW) is used.

We have successfully developed integration friendly dual metal gate process utilizing a dual thickness metal inserted poly-Si stacks (DT-MIPS) structure; poly-Si/TaN/HfON stacks for nMOS and poly-Si/capping metal layer(c-ML)/AlOx/TaN/HfON stacks for pMOS. First, in spite of different metal thickness on n/pMOS, a high-selectivity gate etch process can completely remove metal and HfON layers from the S/D active regions with negligible Si recess in both n/pMOS. Consequently, in both short and long channel devices, n/pMOS Vth values of ~plusmn0.35 V are obtained without counter channel doping. Moreover, excellent drive currents (620/250 muA/um for n/pMOS at Ioff=20 pA/um and Vdd=1.2 V) are obtained without using any mobility enhancement technique. Finally, we confirm that the estimated operation voltages for 10 years lifetime for both nMOS PBTI and pMOS NBTI are well beyond the 1.2 V.

The authors have successfully developed a mass production friendly single metal gate process utilizing an ultra-thin metal inserted poly-Si stack (UT-MIPS) structure. First, the inserted metal gate thickness effects on device performances are carefully examined, and then the other parameters are optimized to give the best performance. As a results, low and symmetrical short channel Vth (0.44/-0.48 V for n/pMOS) and excellent drive currents (620/230 muA/mum for n/pMOS at Ioff =20pA/mum and Vdd=1.2 V) are obtained without using any mobility enhancement strain technology. The estimated operation voltage for 10 years lifetime of optimized UT-MIPS devices (1.25 V for nMOS PBTI and 1.5 V pMOS NBTI) are well beyond the 1.2 V, showing the good reliability characteristics of UT-MIPS devices as well

We propose a novel Vth, control method for HfSiON (or HfO2) with poly-Si and metal inserted poly-Si stacks (MIPS) gates. By using a selective AlOx etch (SAE) process, we successfully integrate dual high-k gate oxide scheme; HfSiO/poly-Si stack for nMOS and HfSiO/AlOx/poly-Si stack for pMOS. Therefore, symmetrical Vth values of 0.43V(nMOS)/-0.44V (pMOS) have been obtained in poly-Si gate. For MIPS gate, we perform the SAE process with impurity incorporation at the channel region, such as N 2 for nMOS and F for pMOS. Consequently, nMOS Vth of 0.35V and pMOS Vth of -0.45V are obtained without counter channel doping. Moreover, we find out that impurity incorporation at the channel also improves mobility and reliability characteristics. Finally, by using the SAE process with impurity incorporation, maximum operating voltages above 1.0V are obtained by an extrapolated 10 years lifetime