• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.167-169
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• 2009

We have carried out quantitative structure and property analysis of the nanoporous structures of low dielectric constant (low-k) carbon-doped silicon oxide (SiCOH) films, which were deposited with plasma enhanced chemical vapor deposition (PECVD) using vinyltrimethylsilane (VTMS), divinyldimethylsilane (DVDMS), and tetravinylsilane (TVS) as precursor and oxygen as an oxidant gas. We found that the SiCOH film using VTMS only showed well defined spherical nanopores within the film after thermal annealing at $450^{\circ}C$ for 4 h. The average pore radius of the generated nanopores within VTMS SiCOH film was 1.21 nm with narrow size distribution of 0.2. It was noted that thermally labile $C_{x}H_{y}$ phase and Si-$CH_3$ was removed to make nanopore within the film by thermal annealing. Consequently, this induced that decrease of average electron density from 387 to $321\;nm^{-3}$ with increasing annealing temperature up to $450^{\circ}C$ and taking a longer annealing time up to 4 h. However, the other SiCOH films showed featureless scattering profiles irrespective of annealing conditions and the decreases of electron density were smaller than VTMS SiCOH film. Because, with more vinyl groups are introduced in original precursor molecule, films contain more organic phase with less volatile characteristic due to the crosslinking of vinyl groups. Collectively, the presenting findings show that the organosilane containing vinyl group was quite effective to deposit SiCOH/$C_{x}H_{y}$ dual phase films, and post annealing has an important role on generation of pores with the SiCOH film.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.151-151
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• 2003

열화학기상증착법(Thermal-CVD)을 이용하여 SOI(snilicon-on-insulator)기판과 실리콘기판 상에 단결정 3C-SiC 이종박막을 동시에 성장하고, 그 특성을 비교 분석하였다. 결정성 평가로는 X-선 회절(XRD)분석과 Raman 산란 분광분석, 그리고 투과전자현미경을 이용하였고, 잔류 웅력 비교 분석으로는 laser scanning 방법 과 Raman 산란 분광분석의 3C-SiC LO peak의 위치변화, 그리고 X-선 회절분석의 3C-SiC(004) peak의 위치변화를 이용하였다. 그 결과 SOI 기판과 실리콘 기판상에 고품위의 단결정 3C-SiC 박막이 성장됨을 확인하였고, SOI 기판을 사용한 경우 실리콘 기판에 비해 성장된 3C-SiC 이종박막의 잔류 응력이 실제로 감소됨을 확인하였다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.1
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• pp.34-38
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• 1999

$PbTiO_3$(PT)thin films were prepared by simultaneous of $TiO_2$ and PbO on Si(100) substrate using metaloganic chemical vapor deposition (MOCVD). Titanium tetra-isopropoxide (TTIP) and $Pb(TMHD)_2$were used as source materials. As evaporation temperature and flow rate of TTIP were examined the crystal structure of PT thin films using XRD with setting deposition temperature, flow rate of Pb, and total flow rate of $520^{\circ}C$, 30 sccm, and 750 sccm, respectively. PT thin films could be deposited under 48~$50^{\circ}C$ and 18~22sccm of evaporation temperature and flow rate of TTIP, respectively. It was found that lead, oxygen, and silicon diffused at the iaterface between the film and the substrate.

• Proceedings of the KIEE Conference
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• 1999.11a
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• pp.31-34
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• 1999

In the present study, we fabricated stoichiometric $(Ba_{1-x}Sr_x)TiO_3$ thin films at various substrate temperature and contents using of magnetron sputtering method on optimized Pt-based electrodes (Pt/TiN/$SiO_2$/Si). The substate temperature deposited at 200[ $^{\circ}C$], 400[$^{\circ}C$] and 600[$^{\circ}C$] and crystalline BST thin films show above 400[$^{\circ}C$]. Also, the composition of $(Ba_{1-x}Sr_x)TiO_3$ thin films deposited on Si wafer substrate at 400[$^{\circ}C$] were closed to stoichiometry($1.015{\sim}1.093$ in A/B ratio), but compositional deviation from a stoichiometry is larger as $SrCO_3$ is added. The drastic decrease of dielectric constant and increase of dielectric loss in $(Ba_{1-x}Sr_x)TiO_3$thin films is observed above 100[kHz]. V-I characteristics of $(Ba_{1-x}Sr_x)TiO_3$ thin films show the decrease of leakage current with the increase of $SrCO_3$ contents.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.305-309
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• 2002

We have successfully fabricated a Metal-Ferroelectric-Insulator-Semiconductor (MFIS) structure using Bi$\sub$4-x/La$\sub$x/Ti$_3$O$\sub$12/ (BLT) ferroelectric thin film and SiO$_2$/Nitride/SiO$_2$ (ONO) stacked buffer layers for single transistor type ferroelectric nonvolatile memory applications. BLT films were deposited on 15 nm-thick ONO buffer layer by sol-gel spin-coating. The dielectric constant and the leakage current density of prepared ONO film were measured to be 5.6 and 1.0 x 10$\^$-8/ A/$\textrm{cm}^2$ at 2MV/cm, respectively, It was interesting to note that the crystallographic orientations of BLT thin films were strongly effected by pre-bake temperatures. X-ray diffraction patterns showed that (117) crystallites were mainly detected in the BLT film if pre-baked below 400$^{\circ}C$. Whereas, for the films pre-baked above 500$^{\circ}C$, the crystallites with preferred c-axis orientation were mainly detected. From the C-V measurement of the MFIS capacitor with c-axis oriented BLT films, the memory window of 0.6 V was obtained at a voltage sweep of ${\pm}$8 V, which evidently reflects the ferroelectric memory effect of a BLT/ONO/Si structure.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.34-46
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• 2002

Si-O-C-H films with a low dielectric constant were deposited on a p-type Si(100) substrate using a mixture gases of the bis-trimethylsilyl-methane (BTMSM) and oxygen by an inductively coupled plasma chemical vapor deposition (ICPCYD). High density plasma of about $~10^{12}\textrm{cm}^{-3}$ is obtained at low pressure (<400 mTorr) with rf power of about 300W in ICPCVD where the BTMSM and $O_2$ gases are fully dissociated. Fourier transform infrared (FTIR) spectra and X-ray photoelectron spectroscopy (XPS) spectra show that the film has $Si-CH_3$ and OH-related bonds. The void within films is formed due to $Si-CH_3$ and OH-related bonds after annealing at $500^{\circ}C$ for the as-deposition samples. The lowest relative dielectric constant of annealed film at $500^{\circ}C$ is about 2.1.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.429-432
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• 1999

The growth of $\textrm{YMnO}_3$ films directly on Si(100) substrates by RF magnetron sputtering system has been performed. The structural properties of $\textrm{YMnO}_3$ films on Si(100) by rapid thermal annealing(RTA) analysed by XRD(X-ray diffraction). The c-axis oriented $\textrm{YMnO}_3$ peaks were observed deposited in $\textrm{YMnO}_3$/Si(100) structure at RF power of 100W and at a temperature range of $840^{\circ}C$~$870^{\circ}C$ in oxygen ambient.

• Korean Journal of Materials Research
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• v.24 no.5
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• pp.266-270
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• 2014

Aluminum nitride(AlN) films were grown on the C-face and on the Si-face of (0001) silicon carbide(SiC) substrates using plasma-assisted molecular-beam epitaxy(PA-MBE). This study was focused on first-stage growth manipulation prior to the start of AlN growth. Al pre-exposure, N-plasma pre-exposure, and simultaneous exposure(Al and N-plasma) procedures were used in the investigation. In addition, substrate polarity and, first-stage growth manipulation strongly affected the growth and properties of the AlN films. Al pre-exposure on the C-face and on the Si-face of SiC substrates prior to initiation of the AlN growth resulted in the formation of hexagonal hillocks on the surface. However, crack formation was observed on the C-face of SiC substrates without Al pre-exposure. X-ray rocking-curve measurements revealed that the AlN epilayers grown on the Si-face of the SiC showed relatively lower tilt and twist mosaic than did the epilayers grown on the C-face of the SiC. The results from the investigations reported in this paper indicate that the growth conditions on the Si-face of the SiC without Al pre-exposure was highly preferred to obtain the overall high-quality AlN epilayers formed using PA-MBE.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.138-143
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• 2004

Recently there has been a great world-wide interest in developing and characterizing new nano-structured materials. These newly developed materials are often prepared in limited quantities and shapes unsuitable for the extensive mechanical testing. The development of depth sensing indentation methods have introduced the advantage of load and depth measurement during the indentation cycle. In the present work, ZnO thin films are prepared on Si(111), Si(100) substrates at different temperatures by pulsed laser deposition(PLD) method. Because the potential energy in c-axis is low, the films always show c-axis orientation at the optimized conditions in spite of the different substrates. Thin films are investigated by X-ray diffractometer and Nano indentation equipment. From these measurements it is possible to get elastic modulus and hardness of ZnO thin films on Si substrates.

• Journal of the Korean Ceramic Society
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• v.33 no.7
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• pp.761-770
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• 1996

Silicon carbide (SiC) films were deposited by low pressure chemical vapor deposition (LPCVD) using MTS (CH3SICl3) in a hydrogen atmosphere onto graphite substrates. Depletion effects of reactants which usually occur in the hot wall horizaontal reactor were increased with deposition temperature and pressure. Below 50 torr of total pressure (111) plane was preferenctially grown irrespectrive of deposition temperature and deposition site. Over 50 torr of total pressure however (220) plane was preferentially deposited under 130$0^{\circ}C$ and at inlet site. The surface morphologies of SiC films were uniform at all deposition sites under low pressure but greatly changed with pressure. It shows that a facet structure which was formed above 125$0^{\circ}C$ played an important role in the changed of preferred orientation and surface roughness.