• Journal of Applied Reliability
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• v.18 no.1
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• pp.56-65
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• 2018

Purpose: The purpose of this study is to estimate shelf life of fuze MTSQ (Mechanical Time & Super Quick) KM577A1 from Ammunition Stockpile Reliability Program (ASRP) data. Methods: For many years, ammunition test data had been gathered from ASRP. In this study, lot selection criteria and reliability score of functioning time for fuze are proposed. Reliability score of functioning time and failure data are used to estimate shelf life. Results: The results of this study are as follows; The failure modes of fuze MTSQ KM577A1 are dud, inverse function and mechanical time functioning failure (not operating in intended time). Dud and inverse function are major failure modes. Fuze MTSQ KM577A1's shelf life ($B_5$) is estimated 18.2 years conservatively. Conclusion: Degradation of chemical components in fuze MTSQ KM577A1 is major factor for its reliability. And shelf life ($B_5$) of fuze MTSQ KM577A1 is estimated 18.2 years conservatively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.366-367
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• 2006

In general, HF chemistry lifts off the particles during scrubbing after polishing and effectively removes particles. It is sometimes impossible to apply HF chemistry on W plug due to the degradation of electrical characteristics of a device. In this paper, a post W CMP cleaning process is proposed to remove residue particles without applying HF chemistry. After W CMP, recessed plugs are created, therefore they easily trap slurry particles during CMP process. These particles in recessed plug are not easy to remove by brush scrubbing when $NH_4OH$ chemistry is used for the cleaning because the brush surface can not reach the recessed area of plugs. Buffing with oxide slurry was followed by W CMP due to its high selectivity to W. The buffing polishes only oxide slightly which creates higher plug profiles than surrounding oxide. Higher profiles make the brush contact much more effectively and result in a similar particle removal efficiency even in $NH_4OH$ cleaning to that in HF brush scrubbing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.235-236
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• 2006

The contact resistance and grain boundary potential barrier of ceramic $BaTiO_3$ PTCR were investigated. The electroless plated Ni, evaporated Al, and Ag paste were chosen as electrode materials of PTCR device for comparison analysis before and after heat treatment. The contact resistance of electrode were measured by electrometer (dc), digital multimeter (dc), and LCR meter (ac). In the case of Al electroded samples, the heat treatment and protective oxide layer had high resistance and effect on the stability of PTCR effect against contact resistance degradation, but the Ag-paste had comparably high contact resistance before heat treatment and decreased after heat treatment with safe. On the other hand, the samples with electroless plated Ni electrode had good properties of contact resistance against aging.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.2122-2126
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• 2008

With the degradation of water quality and, at the same time increased water usage, the sources of high quality, for examples, river/stream, municipal reservoir, wells, artisan and surface water, are diminishing. Therefore, the importance of water quality has been emphasized over the years through publications and various literature sources. Even though considerable research has resulted in significant strides for providing interpretive information and mitigation strategies for improvement of waters, the quality of which is still questionable. This study aims to propose a completely independent self-contained system for purifying waters, solar-powered ozone generator. It is a semi-permanent and cost effective environmental solution. Functions of ozone treatment are: 1) to maintain oxidative flexibility, 2) remove harmful chemicals, wastes, and other substances, and 3) prevent epizootic microbial outbreaks. Recent advances in technology have allowed the development of the practical, self-contained and independent solar powered device. Solar electrical producing panels that charge batteries are the key to using these systems anywhere electrical power is not available. This paper invites the readers to examine the problem and consider the viable, proven solution the solar powered ozone purifying system. This paper also introduces basic concept and background of solar powered ozone generators and examine its feasibility for improving water quality in rivers and streams.

• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.1
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• pp.46-52
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• 2012

Separate extraction of source ($R_S$) and drain ($R_D$) resistances caused by process, layout variations and long term degradation is very important in modeling and characterization of MOSFETs. In this work, we propose "Avalanche Hot-Source Method (AHSM)" for simple separated extraction of $R_S$ and $R_D$ in a single device. In AHSM, the high field region near the drain works as a new source for abundant carriers governing the current-voltage relationship in the MOSFET at high drain bias. We applied AHSM to n-channel MOSFETs as single-finger type with different channel width/length (W/L) combinations and verified its usefulness in the extraction of $R_S$ and $R_D$. We also confirmed that there is a negligible drift in the threshold voltage ($V_T$) and the subthreshold slope (SSW) even after application of the method to devices under practical conditions.

• Journal of information and communication convergence engineering
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• v.15 no.2
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• pp.112-116
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• 2017

In this work, we demonstrated a low noise and high linearity low noise amplifier (LNA) monolithic microwave integrated circuit (MMIC) with novel active bias circuit for LTE applications. The device technology used in this work relies on a process involving a $0.25-{\mu}m$ GaAs pseudomorphic high electron mobility transistor (PHEMT). The LNA MMIC with a novel active bias circuit has a small signal gain of $19.7{\pm}1.5dB$ and output third order intercept point (OIP3) of 38-39 dBm in the frequency range 1.75-2.65 GHz. The noise figure (NF) is less than 0.58 dB over the full bandwidth. Compared with the characteristics of the LNA MMIC without using the novel active bias circuit, the OIP3 is improved about 2-3 dBm. The small signal gain and NF showed no significant change after using the active bias circuit. The novel active bias circuit indeed improves the linearity performance of the LNA MMIC without degradation.

• Journal of Information Display
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• v.1 no.1
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• pp.63-69
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• 2000

In order to improve both the level and the stability of electron emission, Mo and Co silicides were formed from Mo mono-layer and Ti/Co bi-layers on single crystal silicon field emitter arrays (FEAs), respectively. Using the slope of Fowler-Nordheim curve and tip radius measured from scanning electron microscopy (SEM), the effective work function of Mo and Co silicide FEAs were calculated to be 3.13 eV and 2.56 eV, respectively. Compared with silicon field emitters, Mo and Co silicide exhibited 10 and 34 times higher maximum emission current, 10 V and 46 V higher device failure voltage, and 6.1 and 4.8 times lower current fluctuation, respectively. Moreover, the emission currents of the silicide FEAs depending on vacuum level were almost the same in the range of $10^{-9}{\sim}10^{-6}$ torr. This result shows that silicide is robust in terms of anode current degradation due to the absorption of air molecules.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.7
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• pp.576-582
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• 2002

Nonvolatile semiconductor memory devices with reoxidized nitrided oxide(RONO) gate dielectrics were fabricated, and nitrogen distribution and bonding species which contribute to memory characteristics were analyzed. Also, memory characteristics of devices depending on the anneal temperatures were investigated. The devices were fabricated by retrograde twin well CMOS processes with $0.35\mu m$ design rule. The processes could be simple by in-situ process in growing dielectric. The nitrogen distribution and bonding states of gate dielectrics were investigated by Dynamic Secondary Ion Mass Spectrometry(D-SIMS), Time-of-Flight Secondary Ion Mass Spectrometry(ToF-SIMS), and X-ray Photoelectron Spectroscopy(XPS). As the nitridation temperature increased, nitrogen concentration increased linearly, and more time was required to form the same reoxidized layer thickness. ToF-SIMS results showed that SiON species were detected at the initial oxide interface which had formed after NO annealing and $Si_2NO$ species within the reoxidized layer formed after reoxidation. As the anneal temperatures increased, the device showed worse retention and degradation properties. It could be said that nitrogen concentration near initial interface is limited to a certain quantity, so the excess nitrogen is redistributed within reoxidized layer and contribute to electron trap generation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.12
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• pp.1283-1288
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• 2004

Metal-ferroelectric-insulator-semiconductor(WFIS) capacitors using rapid thermal annealed LiNbO$_3$/AlN/Si(100) structure were fabricated and demonstrated nonvolatile memory operations. The capacitors on highly doped Si wafer showed hysteresis behavior like a butterfly shape due to the ferroelectric nature of the LiNbO$_3$ films. The typical dielectric constant value of LiNbO$_3$ film in the MFIS device was about 27, The gate leakage current density of the MFIS capacitor was 10$^{-9}$ A/cm$^2$ order at the electric field of 500 kV/cm. The typical measured remnant polarization(2P$_{r}$) and coercive filed(Ec) values were about 1.2 $\mu$C/cm$^2$ and 120 kV/cm, respectively The ferroelectric capacitors showed no polarization degradation up to 10$^{11}$ switching cycles when subjected to symmetric bipolar voltage pulses of 1 MHz. The switching charges degraded only by 10 % of their initial values after 4 days at room temperature.e.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1367-1369
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• 1998

To achieve the ULSI goals of higher density, greater performance and operation speed have been scaled down. However, the reduction of channel length cause undesirable problems such as drop of punchthrough voltage, hot-carrier degradation and high leakage current, etc.. It is shown that the device characteristics depend on process parameters. In this Paper, we catched hold of trends of hot-carrier effects and punchthrough voltages due to variation of some process parameters such as LDD doses(P), spacer lengths, channel doses($BF_2$) and $V_T$ adjusting channel implantation energies using design trend curve (DTC). As the LDD and channel doses increased, hot-carrier phenomena became more severe, and punchthrough voltage was decreased. It were represented that punchthrough and hot carrier effects were critically depend on LDD and channel doses.