• Proceedings of the Materials Research Society of Korea Conference
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• 2004.05a
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• pp.44-44
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• 2004

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.385-386
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• 2008

This paper reports the design of the ultra low power consumption microhotplates for high temperatures. The microhotplates consisting of a platinum-based heating element on AlN/poly 3C-SiC layers were designed. The microhotplate is a $600\times600{\mu}m^2$ square shaped membrane made of $1{\mu}m$ thick ploy 3C-SiC suspended by four legs. The microhotplate was compared with $Si_3N_4/SiO_2/Si_3N_4$(NON) structure microhotplate by COMSOL simulation system. Thermal uniformity, power consumption and thermal characterizations of microhotplates based on 3C-SiC thin film are better than microhotplates with NON structure.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.139-139
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• 2010

금속 실리사이드 나노입자는 열적 및 화학적 안정성이 뛰어나고, 절연막내에 일함수 차이에 따라 깊은 양자 우물구조가 형성되어 비휘발성 메모리 소자를 제작할 수 있다. 그러나 단일 $SiO_2$ 절연막을 사용하였을 경우 저장된 전하의 정보 저장능력 및 쓰기/지우기 시간을 향상시키는 데 물리적 두께에 따른 제한이 따른다. 본 연구에서는 터널장벽 엔지니어링을 통하여 물리적인 두께는 단일 $SiO_2$ 보다는 두꺼우나 쓰기/지우기 동작을 위하여 인가되는 전기장에 의하여 상대적으로 전자가 느끼는 상대적인 터널 절연막 두께를 감소시키는 방법으로 동작속도를 향상 시킨 $SiO_2/Si_3N_4/SiO_2$ 및 $Si_3N_4/SiO_2/Si_3N_4$ 터널 절연막을 사용한 금속 실리사이드 나노입자 비휘발성 메모리를 제조하였다. 제조방법은 우선 p-type 실리콘 웨이퍼 위에 100 nm 두께로 증착된 Poly-Si 층을 형성 한 이후 소스와 드레인 영역을 리소그래피 방법으로 형성시켜 트랜지스터의 채널을 형성한 이후 그 상부에 $SiO_2/Si_3N_4/SiO_2$ (2 nm/ 2 nm/ 3 nm) 및 $Si_3N_4/SiO_2/Si_3N_4$ (2 nm/ 3 nm/ 3 nm)를 화학적 증기 증착(chemical vapor deposition)방법으로 형성 시킨 이후, direct current magnetron sputtering 방법을 이용하여 2~5 nm 두께의 $WSi_2$ 및 $TiSi_2$ 박막을 증착하였으며, 나노입자 형성을 위하여 rapid thermal annealing(RTA) system을 이용하여 $800{\sim}1000^{\circ}C$에서 질소($N_2$) 분위기로 1~5분 동안 열처리를 하였다. 이후 radio frequency magnetron sputtering을 이용하여 $SiO_2$ control oxide layer를 30 nm로 증착한 후, RTA system을 이용하여 $900^{\circ}C$에서 30초 동안 $N_2$ 분위기에서 후 열처리를 하였다. 마지막으로 thermal evaporator system을 이용하여 Al 전극을 200 nm 증착한 이후 리소그래피와 식각 공정을 통하여 채널 폭/길이 $2{\sim}5{\mu}m$인 비휘발성 메모리 소자를 제작하였다. 제작된 비휘발성 메모리 소자는 HP 4156A semiconductor parameter analyzer와 Agilent 81101A pulse generator를 이용하여 전기적 특성을 확인 하였으며, 측정 온도를 $25^{\circ}C$, $85^{\circ}C$, $125^{\circ}C$로 변화시켜가며 제작된 비휘발성 메모리 소자의 열적 안정성에 관하여 연구하였다.

• Journal of the Korean institute of surface engineering
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• v.38 no.3
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• pp.100-105
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• 2005

Cr-Si-C-N coatings were deposited on steel substrate (SKD 11) by a hybrid system of arc ion plating (AIP) and sputtering techniques. From XRD, XPS, and HRTEM analyses, it was found that Cr-Si-C-N had a fine composite microstructure comprising nano-sized crystallites of Cr(C, N) well distributed in the amorphous phase of $Si_3N_4/SiC$ mixture. Microhardness of Cr(C, N) coatings and Cr-Si-N coatings were reported about $\~22 GPa$ and $\~35 GPa$, respectively. As the Si was incorporated into Cr(C, N) coatings, The Cr-Si-C-N coatings having a Si content of $9.2 at.\%$ showed the maximum hardness value. As increased beyond Si content of $9.2 at.\%$, the interaction between nanocrystallites and amorphous phase was gone, the hardness was reduced as dependent on amorphous phase of $Si_3N_4/SiC$. In addition, the average coefficient of Cr-Si-C-N coatings largely decreased compared with Cr(C, N) coatings.

• Journal of the Korean Ceramic Society
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• v.16 no.4
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• pp.206-212
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• 1979

The phase relations and microstructure appeared at 1700℃ in a system of Si3N4-Al2O3-SiO2 were studied. The samples were pressurelessly sintered at 1700℃ for 1hr and reheated at 1600℃ for 1hr under nitrogen atmosphere. The compounds formed were identified by X-ray diffraction method and the microstrues were observed by SEM. The stable phases appeared in this system were X-phase, Si2ON2, β'-Si3N4 and Mullite. From the results of those experiments, it was concluded that the X-phase has very close composition to that proposed by G, K. Layden, Si3Al6O12N2. SEM photographs showed that Si2ON2 was a plate phase and X-phase was a rectagular plate phase.

• Journal of Pharmacopuncture
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• v.7 no.2
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• pp.57-64
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• 2004

This study was carried to identify the component of Small Intestine Meridian Muscle in human, dividing the regional muscle group into outer, middle, and inner layer. the inner part of body surface were opened widely to demonstrate muscles, nerve, blood vessels and the others, displaying the inner structure of Small Intestine Meridian Muscle. We obtained the results as follows; 1. Small Intestine Meridian Muscle is composed of the muscle, nerve and blood vessels. 2. In human anatomy, it is present the difference between a term of nerve or blood vessels which control the muscle of Meridian Muscle and those which pass near by Meridian Muscle. 3. The inner composition of meridian muscle in human arm is as follows ; 1) Muscle ; Abd. digiti minimi muscle(SI-2, 3, 4), pisometacarpal lig.(SI-4), ext. retinaculum. ext. carpi ulnaris m. tendon.(SI-5, 6), ulnar collateral lig.(SI-5), ext. digiti minimi m. tendon(SI-6), ext. carpi ulnaris(SI-7), triceps brachii(SI-9), teres major(SI-9), deltoid(SI-10), infraspinatus(SI-10, 11), trapezius(Sl-12, 13, 14, 15), supraspinatus(SI-12, 13), lesser rhomboid(SI-14), erector spinae(SI-14, 15), levator scapular(SI-15), sternocleidomastoid(SI-16, 17), splenius capitis(SI-16), semispinalis capitis(SI-16), digasuicus(SI-17), zygomaticus major(Il-18), masseter(SI-18), auriculoris anterior(SI-19) 2) Nerve ; Dorsal branch of ulnar nerve(SI-1, 2, 3, 4, 5, 6), br. of mod. antebrachial cutaneous n.(SI-6, 7), br. of post. antebrachial cutaneous n.(SI-6,7), br. of radial n.(SI-7), ulnar n.(SI-8), br. of axillary n.(SI-9), radial n.(SI-9), subscapular n. br.(SI-9), cutaneous n. br. from C7, 8(SI-10, 14), suprascapular n.(SI-10, 11, 12, 13), intercostal n. br. from T2(SI-11), lat. supraclavicular n. br.(SI-12), intercostal n. br. from C8, T1(SI-12), accessory n. br.(SI-12, 13, 14, 15, 16, 17), intercostal n. br. from T1,2(SI-13), dorsal scapular n.(SI-14, 15), cutaneous n. br. from C6, C7(SI-15), transverse cervical n.(SI-16), lesser occipital n. & great auricular n. from cervical plexus(SI-16), cervical n. from C2,3(SI-16), fascial n. br.(SI-17), great auricular n. br.(SI-17), cervical n. br. from C2(SI-17), vagus n.(SI-17),hypoglossal n.(SI-17), glossopharyngeal n.(SI-17), sympathetic trunk(SI-17), zygomatic br. of fascial n.(SI-18), maxillary n. br.(SI-18), auriculotemporal n.(SI-19), temporal br. of fascial n.(SI-19) 3) Blood vessels ; Dorsal digital vein.(SI-1), dorsal br. of proper palmar digital artery(SI-1), br. of dorsal metacarpal a. & v.(SI-2, 3, 4), dorsal carpal br. of ulnar a.(SI-4, 5), post. interosseous a. br.(SI-6,7), post. ulnar recurrent a.(SI-8), circuirflex scapular a.(SI-9, 11) , post. circumflex humeral a. br.(SI-10), suprascapular a.(SI-10, 11, 12, 13), first intercostal a. br.(SI-12, 14), transverse cervical a. br.(SI-12,13,14,15), second intercostal a. br.(SI-13), dorsal scapular a. br.(SI-13, 14, 15), ext. jugular v.(SI-16, 17), occipital a. br.(SI-16), Ext. jugular v. br.(SI-17), post. auricular a.(SI-17), int. jugular v.(SI-17), int. carotid a.(SI-17), transverse fascial a. & v.(SI-18),maxillary a. br.(SI-18), superficial temporal a. & v.(SI-19).

• Journal of the Korean Ceramic Society
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• v.28 no.9
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• pp.667-674
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• 1991

In this study, Kaolin was carbonized at 1300~175$0^{\circ}C$ and its constituent mineral change was investigated. Carbonized kaolin at 1$650^{\circ}C$ was mixed with metallic silicon, formed and nitrified at 135$0^{\circ}C$ in N2-NH3 atmosphere. Properties of this product such as porosity, bulk density, MOR, nitrization rate and oxidation resistence were measured, and its mineralogical changes were investigated by XRD. The results were as follows; 1) $\beta$-SiC was initially synthesized at 150$0^{\circ}C$, and its amount was continuously increased with reaction temperature to 1$700^{\circ}C$. 2) At 1$600^{\circ}C$, mullite was rapidly decomposed and the amounts of $\beta$-SiC and $\alpha$-Al2O3 were increased simultaneously. 3) By adding alkali to kaolin, the decomposition temperature of mullite was dropped approximately 10$0^{\circ}C$, but the amount of $\alpha$-SiC was increased. 4) The highest values of their nitrization rate and MOR were obtained at the specimen of 35 wt% metallic silicon in nitrization reaction. 5) It seems that increment of $\alpha$-Si3N4 and $\alpha$-Al2O3 phase during nitrization was due to the decomposition of Al4SiC4 existed in carbonized kaolin. 6) Si3N4 bonded SiC-Al2O3 composite were fabricated from kaolin at relatively low temperature (135$0^{\circ}C$).

• Journal of the Korean Ceramic Society
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• v.44 no.4 s.299
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• pp.189-193
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• 2007

Effect of additive composition on fracture toughness of in situ-toughened $SiC-Si_3N_4$ composites was investigated for five different additive compositions. The highest toughness $(6.4MPa{\cdot}m^{1/2})\;in\;SiC-Si_3N_4$ composites investigated herein was obtained when an Y-Mg-Si-Al-O-N oxynitride glass was used as a sintering additive. The improvement in fracture toughness was produced by enhanced bridging and deflection by $Si_3N_4$ grains.

• Journal of the Korean Ceramic Society
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• v.30 no.2
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• pp.85-92
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• 1993

Oxynitride glasses in Na-Ca-Si-O-N system were prepared by melting at 135$0^{\circ}C$ for 2 hours in N2 gas. The effects of Si/Na mole ratio and the various Si3N4 contents were investigated. Stable oxynitride glasses can be obtained up to 9wt.% Si3N4 content in case the Si/Na mole ratio was 2.12 and 1.62, but $\beta$-Si3N4 was precipitated at 9wt.% Si3N4 content in case the Si/Na mole rtio was 1.12. Density (p), chemical durability, hardness (Hv), and fracture toughness (KIC) increased with increasing Si3N4 content. In cae the Si/Na mole ratio was 1.12, the increment of properties was remarkable but hardness and fracture toughness did not increase no longer owing to precipitation of $\beta$-Si3N4.

• Journal of the Korean Ceramic Society
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• v.31 no.10
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• pp.1089-1098
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• 1994

The effect of Si3N4 addition on the microstructure and PTCR characteristics of BaTiO3 was studied. When 0.1 mol% Sb2O3-doped BaTiO3 codoped with Si3N4 (0.1, 0.25, 0.5, 0.75, and 1 wt%, respectively) were sintered, their microstructures were changed by the amount of the liquid phase as a result of eutectic reaction at 126$0^{\circ}C$. By these microstructural changes, the specific resistivity ratio($\rho$max/$\rho$min) with Si3N4 content variation of 0.1 mol% Sb2O3-doped BaTiO3 ceramics sintered at 130$0^{\circ}C$ for 1 hour varied between 3.70$\times$102(0.1 wt% Si3N4) to 1.16$\times$103 (1wt% Si3N4).