• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제40회 동계학술대회 초록집
• /
• pp.52-52
• /
• 2011

A novel deposition process for n-type nanocrystalline silicon (n-type nc-Si) thin films at room temperature has been developed by adopting the neutral beam assisted chemical vapor deposition (NBa-CVD). During formation of n-type nc-Si thin film by the NBa-CVD process with silicon reflector electrode at room temperature, the energetic particles could induce enhance doping efficiency and crystalline phase in polymorphous-Si thin films without additional heating on substrate; The dark conductivity and substrate temperature of P-doped polymorphous~nano crystalline silicon thin films increased with increasing the reflector bias. The NB energy heating substrate(but lower than $80^{\circ}C$ and increase doping efficiency. This low temperature processed doped nano-crystalline can address key problem in applications from flexible display backplane thin film transistor to flexible solar cell.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 1995년도 제9회 학술발표회 논문개요집
• /
• pp.20-21
• /
• 1995

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2008년도 제35회 하계학술대회 초록집
• /
• pp.331-331
• /
• 2008

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 1996년도 제11회 학술발표회 논문개요집
• /
• pp.113-114
• /
• 1996

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.289.1-289.1
• /
• 2016

Germanium (Ge) with higher carrier mobility and a lower crystallization temperature has been considered as the channel material of thin-film transistors for display applications. Various methods were studied for crystallizaion of poly-Ge from amorphous Ge at low temperature. Especially Metal induced crystalliazation (MIC) process was widely studied because low process cost. In this paper, we investigate copper diffusion process of different thick (70 nm, 350 nm) poly-Ge film obtained by MIC process at various temperatures (250, 300, and $350^{\circ}C$) through atomic force microscopy (AFM), Raman spectroscopy, and secondary ion mass spectroscopy (SIMS) measurement. Crystallization completeness and grain size was similar in all the conditions. Copper diffusion profile of 370 nm poly-Ge film show simirly results regardless of process temperature. However, copper diffusion profile of 70 nm poly-Ge film show different results by process temperature.

• 소성∙가공
• /
• 제18권3호
• /
• pp.217-222
• /
• 2009

Automobile industries have been focusing their efforts on the development of exhaust manifolds using high temperature stainless steels. Exhaust manifolds fabricated with stainless steels can be categorized into tubular and cast ones. The former is usually manufactured by forming and welding process and the latter by vacuum casting process. In the present study, high temperature mechanical properties of 5 austenitic and 4 ferritic stainless steels were investigated by performing a series of high temperature tensile and low cycle fatigue tests. One of the austenitic stainless steels was vacuum cast and the others sand cast. Fatigue life of ferritic stainless steels was higher than that of austenitic ones.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
• /
• pp.253-253
• /
• 2012

Low temperature SiOx film process has being required for both silicon and oxide (IGZO) based low temperature thin film transistor (TFT) for application of flexible display. In recent decades, from low density and high pressure such as capacitively coupled plasma (CCP) type plasma enhanced chemical vapor deposition (PECVD) to the high density plasma and low pressure such as inductively coupled plasma (ICP) and electron cyclotron resonance (ECR) have been used to researching to obtain high quality silicon oxide (SiOx) thin film at low temperature. However, these plasma deposition devices have limitation of controllability of process condition because process parameters of plasma deposition such as RF power, working pressure and gas ratio influence each other on plasma conditions which non-leanly influence depositing thin film. In compared to these plasma deposition devices, neutral beam assisted chemical vapor deposition (NBaCVD) has advantage of independence of control parameters. The energy of neutral beam (NB) can be controlled independently of other process conditions. In this manner, we obtained NB dependent high crystallized intrinsic and doped silicon thin film at low temperature in our another papers. We examine the properties of the low temperature processed silicon oxide thin films which are fabricated by the NBaCVD. NBaCVD deposition system consists of the internal inductively coupled plasma (ICP) antenna and the reflector. Internal ICP antenna generates high density plasma and reflector generates NB by auger recombination of ions at the surface of metal reflector. During deposition of silicon oxide thin film by using the NBaCVD process with a tungsten reflector, the energetic Neutral Beam (NB) that controlled by the reflector bias believed to help surface reaction. Electrical and structural properties of the silicon oxide are changed by the reflector bias, effectively. We measured the breakdown field and structure property of the Si oxide thin film by analysis of I-V, C-V and FTIR measurement.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.160-160
• /
• 2016

In this study, we applied the low temperature curing Ag paste to replace PVD System. The electrode formation of low temperature curing Ag paste for silicon Hetero-junction solar cells is important for improving device characteristics such as adhesion, contact resistance, fill factor and conversion efficiency. The low temperature curing Ag paste is composed various additives such as solvent, various organic materials, polymer, and binder. it depends on the curing temperature conditions. The adhesion of the low temperature curing Ag paste was decided by scratch test. The specific contact resistance was measured using the transmission line method. All of the Ag electrodes were experimented at various curing temperatures within the temperature range of $160^{\circ}C-240^{\circ}C$, at $20^{\circ}C$ intervals. The curing time was also changed by varying the conditions of 10-50min. In the optimum curing temperature $200^{\circ}C$ and for 20 min, the measured contact resistance is $19.61m{\Omega}cm^2$. Over temperature $240^{\circ}C$, confirmed bad contact characteristic. We obtained photovoltaic parameter of the industrial size such as Fill Factor (FF), current density (Jsc), open-circuit voltage (Voc) and convert efficiency of up to 76.2%, 38.1 mA/cm2, 646 mV and 18.3%, respectively.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2010년도 제39회 하계학술대회 초록집
• /
• pp.294-294
• /
• 2010

Over the last decade, dye-sensitized solar cell (DSSC) has attracted much attention due to the high solar-to-electricity conversion efficiency up to 10% as well as low cost compared with p-n junction photovoltaic devices. DSSC is composed of mesoporous TiO2 nanoparticle electrodes coated with photo-sensitized dye, the redox electrolyte and the metal counter electrode. The performances of DSSC are dependent on constituent materials and interface as well as device structure. Replacing the heavy glass substrate with plastic materials is crucial to enlarge DSSC applications for the competition with inorganic based thin film photovoltaic devices. One of the biggest problems with plastic substrates is their low-temperature tolerance, which makes sintering of the photoelectrode films impossible. Therefore, the most important step toward the low-temperature DSSC fabrication is how to enhance interparticle connection at the temperature lower than $150^{\circ}C$. In this talk, the key issues for high efficiency plastic solar cells will be discussed, and several strategies for the improvement of interconnection of nanoparticles and bendability will also be proposed.

• 센서학회지
• /
• 제27권5호
• /
• pp.300-305
• /
• 2018

The uncooled microbolometer thermal sensor for low cost and mass volume was designed to target the new infrared market that includes smart device, automotive, energy management, and so on. The microbolometer sensor features 80x60 pixels low-resolution format and enables the use of wafer-level vacuum packaging (WLVP) technology. Read-out IC (ROIC) implements infrared signal detection and offset correction for fixed pattern noise (FPN) using an internal digital to analog convertor (DAC) value control function. A reliable WLVP thermal sensor was obtained with the design of lid wafer, the formation of Au80%wtSn20% eutectic solder, outgassing control and wafer to wafer bonding condition. The measurement of thermal conductance enables us to inspect the internal atmosphere condition of WLVP microbolometer sensor. The difference between the measurement value and design one is $3.6{\times}10-9$ [W/K] which indicates that thermal loss is mainly on account of floating legs. The mean time to failure (MTTF) of a WLVP thermal sensor is estimated to be about 10.2 years with a confidence level of 95 %. Reliability tests such as high temperature/low temperature, bump, vibration, etc. were also conducted. Devices were found to work properly after accelerated stress tests. A thermal camera with visible camera was developed. The thermal camera is available for non-contact temperature measurement providing an image that merged the thermal image and the visible image.