• Transactions on Electrical and Electronic Materials
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• 제8권3호
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• pp.110-114
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• 2007

Dependence of the thermal stability of nickel silicide on the film stress of inter layer dielectric (ILD) layer has been investigated in this study and silicon nitride $(Si_3N_4)$ layer is used as an ILD layer. Nickel silicide was formed with a one-step rapid thermal process at $500^{\circ}C$ for 30 sec. $2000{\AA}$ thick $Si_3N_4$ layer was deposited using plasma enhanced chemical vapor deposition after the formation of Ni silicide and its stress was split from compressive stress to tensile stress by controlling the power of power sources. Stress level of each stress type was also split for thorough analysis. It is found that the thermal stability of nickel silicide strongly depends on the stress type as well as the stress level induced by the $Si_3N_4$ layer. In the case of high compressive stress, silicide agglomeration and its phase transformation from the low-resistivity nickel mono-silicide to the high-resistivity nickel di-silicide are retarded, and hence the thermal stability is obviously improved a lot. However, in the case of high tensile stress, the thermal stability shows the worst case among the stressed cases.

• 한국재료학회지
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• 제7권3호
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• pp.196-202
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• 1997

PLT 박막의 증착방법으로 ECR PECVD법을 이용한 경우 $440~500^{\circ}C$의 비교적 낮은 온도에서 순수한 perovskite구조를 가진$(Pb,La)TiO_{3}$박막을 성공적으로 제조하였다. 기판온도 증가에 따라 반응기체 및 산화물(특히 Pb oxkde)의 휘발성이 증대되어 증착속도가 감소하고 (Pb oxide)의 휘발성이 증대되어 증착속도가 감소하고 (Pb+La)/Ti조성비가 감소하였다. $460~480^{\circ}C$의 온도범위에서 증착한 PLT 박막이 화학양론비를 가장 잘 만족하였으며 이때 높은 유전상수와 가장 우수한 누설전류 특성을 나타내었다. $La(DPM)_{3}$ 유입량 증가에 따라 $(Pb, La)TiO_{3}$ 박막의 La 조성이 거의 직선적으로 비례하여 증가하였는데 La/Ti비가 3.0%에서 9.5%까지 증가함에 따라 PLT 박막의 유전 상수는 360부터 650까지 증가하였고 100kV/cm 전기장하에서의 누설전류도 $4{\times}10^{-5}$에서 $4{\times}10_{-8}A/cm^2$로 향상되었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.58-58
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• 1999

The diamond films which can be applied to SOD (silicon-on-diamond) structure were deposited on Si(100) substrate using CO/H2 CH4/H2 source gases by microwave plasma chemical vapor deposition(MPCVD), and SOD structure have been fabricated by poly-silicon film deposited on the diamond/Si(100) structure y low pressure chemical vapor deposition(LPCVD). The phase of the diamond film, surface morpholog, and diamond/Si(100) interface were confirmed by X-ray diffraction(XRD), scanning electron microscopy(SEM), atomic force microscopy(AFM), and Raman spectroscopy. The dielectric constant, leakage current and resistivity as a function of temperature in films are investigated by C-V and I-V characteristics and four-point probe method. The high quality diamond films without amorphous carbon and non-diamond elements were formed on a Si(100), which could be obtained by CO/H2 and CH4/H2 concentration ratio of 15.3% and 1.5%, respectively. The (111) plane of diamond films was preferentially grown on the Si(100) substrate. The grain size of the films deposited by CO/H2 are gradually increased from 26nm to 36 nm as deposition times increased. The well developed cubo-octahedron 100 structure nd triangle shape 111 are mixed together and make smooth and even film surface. The surface roughness of the diamond films deposited by under the condition of CO/H2 and CH4/H2 concentration ratio of 15.3% and 1.5% were 1.86nm and 3.7 nm, respectively, and the diamond/Si(100) interface was uniform resistivity of the films deposited by CO/H2 concentration ratio of 15.3% are obtained 5.3, 1$\times$10-9 A/cm, 1 MV/cm2, and 7.2$\times$106 $\Omega$cm, respectively. In the case of the films deposited by CH4/H2 resistivity are 5.8, 1$\times$10-9 A/cm, 1 MV/cm, and 8.5$\times$106 $\Omega$cm, respectively. In this study, it is known that the diamond films deposited by using CO/H2 gas mixture as a carbon source are better thane these of CH4/H2 one.

• 센서학회지
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• 제5권6호
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• pp.51-59
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• 1996

실리콘기판과의 스트레스균형이 이루어진 150 nm-$Si_{3}N_{4}$/300 nm-$SiO_{2}$/150 nm-$Si_{3}N_{4}$ 다이아프레임위에 백금 박막히터 및 Bi-Sb 열전대배열을 형성하여 히터에서 실리콘기판으로 전달되는 열량의 차단효과가 현저히 개선된 유체센서를 제작하였다. 백금 박막히터는 유전체 다이아프레임의 열차단 효과때문에 비선형 전류-전압 특성을 나타내었고, 이 히터의 저항온도계수는 약 $0.00378\;/^{\circ}C$였으며, 또한 Bi-Sb 열전대의 Seebeck계수는 약 $97\;{\mu}V/K$였다. 기체의 열전도도가 증가할수록 유체센서가 나타내는 열기전력은 감소하였으며, 히터온도가 증가하거나 히터와 열전대사이의 거리가 감소할수록 센서의 감도는 증가하였다. 히터전압을 약 2.5V로 하였을 때 유체센서의 $N_{2}$유량에 대한 감도는 약 $1.27\;mV{\cdot}(sccm)^{-1/2}$였고, 열응답시간은 약 0.13 초였다.

• 한국재료학회지
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• 제8권11호
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• pp.1067-1073
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• 1998

CO와 $H_2$의 탄소원을 사용한 마이크로파 플라즈마 화학기상증착 방법으로 SOD 구조에 적용될 양질의 다이아몬드 박막을 형성하였고, SOD 구조를 형성하기 위해 diamond/Si(100) 구조 위에 poly-Si 박막을 저압화학기상 증착법으로 제작하였다. CO/$H_2$탄소원의 유량비 증가에 따라 다이아몬드의 결정은 octahedron 구조에서 cubo-octahedron 구조로 바뀌었으며, 결정면은 {111}과 {100}으로 혼합되어 형성되었다. 비정질 carbon과 non-diamond성분이 없는 양질의 다이아몬드 박막은 CO/$H_2$의 유량비가 0.18일 때 형성되었으며, 주 결정상은 (111) 면이었다. diamond/Si(100) 계면은 void가 없는 평활한 계면을 이루었으며, 다이아몬드 박막의 유전상수, 누설전류와 비저항은 각각 $5.31\times10^{-9}A/cm^2$ 그리고 $9\times{10^7}{\Omega}cm$이었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.168-168
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• 2008

Dimension of a transistor has rapidly shrunk to increase the speed of device and to reduce the power consumption. However, it is accompanied with several problems like direct tunneling through the gate dioxide layer and low conductivity characteristic of poly-Si gate in nano-region. To cover these faults, study of new materials is urgently needed. Recently, high dielectric materials like $Al_2O_3$, $ZrO_2$, and $HfO_2$ are being studied for equivalent oxide thickness (EOT). However, poly-Si gate is not compatible with high-k materials for gate-insulator. Poly Si gate with high-k material has some problems such as gate depletion and dopant penetration problems. Therefore, new gate structure or materials that are compatible with high-k materials are also needed. TiN for metal/high-k gate stack is conductive enough to allow a good electrical connection and compatible with high-k materials. According to this trend, the study on dry etching of TiN for metal/high-k gate stack is needed. In this study, the investigations of the TiN etching characteristics were carried out using the inductively coupled $BCl_3$-based plasma system and adding $Cl_2$ gas. Dry etching of the TiN was studied by varying the etching parameters including $BCl_3$/Ar gas mixing ratio, RF power, DC-bias voltage to substrate, and $Cl_2$ gas addition. The plasmas were characterized by optical emission spectroscopy analysis. Scanning electron microscopy was used to investigate the etching profile.

• 한국자기학회지
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• 제15권2호
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• pp.67-75
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• 2005

경량 전파흡수체 구현 방안의 하나로 저밀도(약 0.2g/cc) 중공미세구 표면에 수 ${\cal}um$ 두께의 Co 피막을 무전해 도금에 의해 코팅하고, 고주파 전자기 특성 및 전파흡수특성을 조사하였다. Co 도금은 활성화 처리와 도금공정 2단계 과정을 거쳐 시행되었다. 도금공정의 반복에 의해 두께 $2{\~}3\mu$m의 균일한 Co 피막을 얻을 수 있었다. 이 분말을 실리콘 고무와 혼합하여 복합체를 제조하고, 고주파 전자기 물성 및 전파흡수특성을 회로망 분석기로 측정하였다. Co 피막의 강자성 특성 및 전도 특성에 의해 높은 자기손실 및 유전상수를 얻을 수 있었다. 이와 같은 전자기적 특성에 의해 GHz 대역에서 우수한 전파흡수특성(두께 2.0$\~$2.5mm, 전파흡수능 20dB 이상)이 확인되었다. 특히 Co 도금 중공미세구의 밀도(0.84 g/cc)는 페라이트(5.0 g/cc)에 비해 약 1/6에 불과하기 때문에 경량 전파흡수체로서 응용가치가 매우 높음을 제시할 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.362-362
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• 2014

Atomic layer deposition (ALD) can be regarded as a special variation of the chemical vapor deposition method for reducing film thickness. ALD is based on sequential self-limiting reactions from the gas phase to produce thin films and over-layers in the nanometer scale with perfect conformality and process controllability. These characteristics make ALD an important film deposition technique for nanoelectronics. Tantalum pentoxide ($Ta_2O_5$) has a number of applications in optics and electronics due to its superior properties, such as thermal and chemical stability, high refractive index (>2.0), low absorption in near-UV to IR regions, and high-k. In particular, the dielectric constant of amorphous $Ta_2O_5$ is typically close to 25. Accordingly, $Ta_2O_5$ has been extensively studied in various electronics such as metal oxide semiconductor field-effect transistors (FET), organic FET, dynamic random access memories (RAM), resistance RAM, etc. In this experiment, the variations of chemical and interfacial state during the growth of $Ta_2O_5$ films on the Si substrate by ALD was investigated using in-situ synchrotron radiation photoemission spectroscopy. A newly synthesized liquid precursor $Ta(N^tBu)(dmamp)_2$ Me was used as the metal precursor, with Ar as a purging gas and $H_2O$ as the oxidant source. The core-level spectra of Si 2p, Ta 4f, and O 1s revealed that Ta suboxide and Si dioxide were formed at the initial stages of $Ta_2O_5$ growth. However, the Ta suboxide states almost disappeared as the ALD cycles progressed. Consequently, the $Ta^{5+}$ state, which corresponds with the stoichiometric $Ta_2O_5$, only appeared after 4.0 cycles. Additionally, tantalum silicide was not detected at the interfacial states between $Ta_2O_5$ and Si. The measured valence band offset value between $Ta_2O_5$ and the Si substrate was 3.08 eV after 2.5 cycles.

• 센서학회지
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• 제8권2호
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• pp.115-123
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• 1999

PSG(800nm)/$Si_3N_4$ (150nm)로 구성된 유전체 membrane 윗면에 heater와 감지전극을 등일면상에 동시에 형성하였다. 제작된 소자의 전체 면적은 $3.78{\times}3.78mm^2$이고, diaphragm의 면적은 $1.5{\times}1.5mm^2$이며, 감지막치 면적은 $0.24{\times}0.24mm^2$였다. 그리고 diaphragm내의 열분포 분석을 유한요소법을 이용하여 수행하였으며, 실제로 제작된 소자의 열분포와 비교하였다. 소비전력은 동작온도 $350^{\circ}C$에서 약 85mW였다. Sn 금속막을 상온과 $232^{\circ}C$의 두 가지 기판온도에서 열증착하였고, 이를 $650^{\circ}C$의 산소분위기에서 3시간 열산화함으로써 $SnO_2$ 감지막을 형성하였다. 그리고 이를 SEM과 XRD로 특성을 분석하였다. 제작된 소자에 대해서 온도 및 습도에 대한 감지막의 영향 및 부탄가스에 대한 반응특성도 조사하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.169-169
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• 2008

To keep pace with scaling trends of CMOS technologies, high-k metal oxides are to be introduced. Due to their high permittivity, high-k materials can achieve the required capacitance with stacks of higher physical thickness to reduce the leakage current through the scaled gate oxide, which make it become much more promising materials to instead of $SiO_2$. As further studying on high-k, an understanding of the relation between the etch characteristics of high-k dielectric materials and plasma properties is required for the low damaged removal process to match standard processing procedure. There are some reports on the dry etching of different high-k materials in ICP and ECR plasma with various plasma parameters, such as different gas combinations ($Cl_2$, $Cl_2/BCl_3$, $Cl_2$/Ar, $SF_6$/Ar, and $CH_4/H_2$/Ar etc). Understanding of the complex behavior of particles at surfaces requires detailed knowledge of both macroscopic and microscopic processes that take place; also certain processes depend critically on temperature and gas pressure. The choice of $BCl_3$ as the chemically active gas results from the fact that it is widely used for the etching o the materials covered by the native oxides due to the effective extraction of oxygen in the form of $BCl_xO_y$ compounds. In this study, the surface reactions and the etch rate of $Al_2O_3$ films in $BCl_3/Cl_2$/Ar plasma were investigated in an inductively coupled plasma(ICP) reactor in terms of the gas mixing ratio, RF power, DC bias and chamber pressure. The variations of relative volume densities for the particles were measured with optical emission spectroscopy (OES). The surface imagination was measured by AFM and SEM. The chemical states of film was investigated using X-ray photoelectron spectroscopy (XPS), which confirmed the existence of nonvolatile etch byproducts.