• 한국세라믹학회지
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• 제37권3호
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• pp.280-287
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• 2000

Adsorption behavior and amount of phenolic resin followed silica (SiO2) formation onto silicon nitride(Si3N4) surface were investigated using electrokinetic sonic amplitude (ESA) technique and with UV spectrometer, to fabricate Si3N4/SiC nano-composite based on reaction between SiO2 formed and phenolic resin absorbed onto Si3N4 particle. The amount of SiO2 formed and carbon from phenolic resin absorbed onto Si3N4 surface were calculated quantitatively to adjust the reaction between SiO2 and phenolic resin, resulting in no residual SiO2 and carbon. As a result, pre-heated tempeature for optimized reaction was below 25$0^{\circ}C$, in which there was no residual SiO2 and carbon.

• 한국세라믹학회지
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• 제44권4호
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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.

• 한국세라믹학회지
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• 제51권5호
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• pp.386-391
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• 2014

Silicon nitride ($Si_3N_4$) is regarded as one of the most promising materials for high temperature structural applications due to its excellent mechanical properties at both room and elevated temperatures. However, one high-temperature $Si_3N_4$ material intended for use in radomes has a relatively high dielectric constant of 7.9 - 8.2 at 8 - 10 GHz. In order to reduce the dielectric constant of the $Si_3N_4$, an in-situ reaction process was used to fabricate $Si_3N_4-SiO_2$-BN composites. In the present study, an in-situ reaction between $B_2O_3$ and $Si_3N_4$, with or without addition of BN in the starting powder mixture, was used to form the composite. The in-situ reaction process resulted in the uniform distribution of the constituents making up the composite ceramic, and resulted in good flexural strength and dielectric constant. The composite was produced by pressure-less sintering and hot-pressing at $1650^{\circ}C$ in a nitrogen atmosphere. Microstructure, flexural strength, and dielectric properties of the composites were evaluated with respect to their compositions and sintering processes. The highest flexural strength (193 MPa) and lowest dielectric constant (5.4) was obtained for the hot-pressed composites. The strength of these $Si_3N_4-SiO_2$-BN composites decreased with increasing BN content.

• 접착 및 계면
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• 제24권2호
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• pp.60-63
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• 2023

AlGaN/GaN 이종접합 구조는 이차원 전자 가스층(2-DEG)으로 인해 높은 전자이동도를 갖고 있으며, 넓은 밴드갭을 갖기 때문에 고온에서 높은 항복전압을 갖는 특성을 가지고 있어, 고전력, 고주파 전자 소자로 주목받고 있다. 이러한 이점을 갖고 있음에도 불구하고, 전류 붕괴 등의 다양한 소자 신뢰성에 영향을 주는 인자들이 있기 때문에 이를 해결하고자, 본 논문에서는 금속-유기-화학기상증착법을 이용하여 AlGaN/GaN 이종 접합구조와 SiN 패시베이션 층을 연속 증착시켰다. 이를 통해 HEMTs소자에 SiN패시베이션이 미치는 재료 특성 및 전기적 특성을 분석했으며, 결과를 바탕으로 저주파 잡음 특성을 측정해 소자의 전도 메커니즘 모델과 채널 내의 결함의 원인에 대해서 분석하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.657-657
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• 2013

In-situ observations of nano-scale behavior of nanomaterials are very important to understand onthe nano-scale phenomena associated with phase change, atomic movement, electrical or optical properties, and even reactions which take place in gas or liquid phases. We have developed on the in-situ experimental technologies of nano-materials (nano-cluster, nanowire, carbon nanotube, and graphene, et al.) and their interactions (percolation of metal nanoclusters, inter-diffusion, metal contacts and phase changes in nanowire devices, formation of solid nano-pores, melting behavior of isolated nano-metal in a nano-cup, et al.) by nano-discovery membrane platform [1-4]. Between two microelectrodes on a silicon nitride membrane platform, electrical percolations of metal nano-clusters are observed with nano-structures of deposited clusters. Their in-situ monitoring can make percolation devices of different conductance, nanoclusters based memory devices, and surface plasmonic enhancement devices, et al. As basic evidence on the phase change memory, phase change behaviors of nanowire devices are observed at a nano-scale.

• 한국진공학회지
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• 제3권3호
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• pp.360-367
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• 1994

Si2H6PH3 혼합기체를 사용하여 증착된 in-situ P-doped 비정질 실리콘과 SiH4 기체를사용하여 증착한후에 As+ 이온주입에 의해 도핑시킨 다결정 실리콘 박막을 하부 전극으로 하는 캐패시터를 형성 하였다. 여기서 유전박막층은 자연산화막 화학증착된 실리콘질화막 및 질화막의 산화에 의해 형성된 O-N-O 구조를 갖는 것이었다. 두 종류의 하부전극에 따른 캐패시터의 전기적 특서을 조사하였다. 전기 적 특성으로는 정전용량, 누설전류, 절연파괴전압 및 TDDB 등이었다. 이 가운데 정전용량, 누설전류 및 절연파괴전압은 하부전극에 따라 큰 차이를 보이지않았다. 그러나 음의 전장하에서의 TDDB 특성은 in-situ P-doped 비정실 실리콘이 하부전극인 캐패시터가 As+ 이온 주입실리콘이 하부전극인 것에 비해 더우수하였다. 이와 같은 TDDB 특성의 차이는 하부전극 실리콘의 integrity 차이로 인한 자연산화막의 결함 정도의 차이에 기인하는 것 같다. 이를 뒷받침하는 것으로 투과전자현미경 단면사진으로 확인하였 다. Shallow junction을 유지하는데도 in-situ P-doped 비정실 실리콘은 만족할 만한 결과를 보이며 박 막자체의 면저항값도 낮출 수 있어 초고집적 회로의 캐패시터 전극으로서 이용될 수 있는 것으로 평가 되었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.149-153
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• 2003

Chemical mechanical polishing (CMP) technology for global planarization of multi-level inter-connection structure has been widely studied for the next generation devices. CMP process has been paid attention to planarized pre-metal dielectric (PMD), inter-layer dielectric (ILD) interconnections. Expecially, shallow trench isolation (STI) used to CMP process on essential. Recently, the direct STI-CMP process without the conventional complex reverse moat etch process has established by using slurry additive with the high selectivity between $SiO_2$ and $Si_3N_4$ films for the purpose of process simplification and n-situ end point detection(EPD). However, STI-CMP process has various defects such as nitride residue, tom oxide and damage of silicon active region. To solve these problems, in this paper, we studied the planarization characteristics using a high selectivity slurry(HSS). As our experimental results, it was possible to achieve a global planarization and STI-CMP process could be dramatically simplified. Also we estimated the reliability through the repeated tests with the optimized process conditions in order to identify the reproducibility of HSS STI-CMP process.