• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.173-174
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• 2007

반도체 소자가 발달함에 따라서 박막은 더욱 다층화 되고 그 두께는 줄어들고 있다. 따라서 소자의 초고집적화를 위해서는 각 박막의 두께를 더욱 작게 하여야 한다. 또한 반도체 소자 제조 공정에서는 Si 기판과 금속 박막간의 확산이 커다란 문제로 부각되어 왔다. 특히 Cu는 높은 확산성에 의하여 Si 기판과 접합에서 많은 확산에 의한 문제가 발생하게 되며, 또한 선폭이 줄어듦에 따라 고열이 발생하여 실리콘으로 spiking이 발생하게 된다. 이러한 확산을 방지하기 위하여 금속 배선과 Si기판 사이에는 필연적으로 확산방지막을 삽입하게 되었다. 기존의 연구에서는 $1000\;{\AA}$의 W-B-C-N 확산방지막을 제작하여 연구하였다. 이 논문에서는 Cu의 확산을 방지하기 위한 W-B-C-N 확산방지막을 다양한 두께로 제작하여 그 특성을 확인하여 초고집적화를 위한 더욱 얇은 두께의 W-B-C-N 확산방지막에 대하여 연구하였다. W-B-C-N 확산방지막의 두께 변화에 대한 특성을 확인하기 위하여 $900^{\circ}C$까지 열처리 한 후 그 면저항을 측정하였다.

• 한국재료학회지
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• 제28권4호
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• pp.208-213
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• 2018

Epitaxial ($11{\bar{2}}0$) a-plane GaN films were grown on a ($1{\bar{1}}02$) R-plane sapphire substrate with photoresist (PR) masks using metal organic chemical vapor deposition (MOCVD). The PR mask with striped patterns was prepared using an ex-situ lithography process, whereas carbonization and heat treatment of the PR mask were carried out using an in-situ MOCVD. The heat treatment of the PR mask was continuously conducted in ambient $H_2/NH_3$ mixture gas at $1140^{\circ}C$ after carbonization by the pyrolysis in ambient $H_2$ at $1100^{\circ}C$. As the time of the heat treatment progressed, the striped patterns of the carbonized PR mask shrank. The heat treatment of the carbonized PR mask facilitated epitaxial lateral overgrowth (ELO) of a-plane GaN films without carbon contamination on the R-plane sapphire substrate. Thhe surface morphology of a-plane GaN films was investigated by scanning electron microscopy and atomic force microscopy. The structural characteristics of a-plane GaN films on an R-plane sapphire substrate were evaluated by ${\omega}-2{\theta}$ high-resolution X-ray diffraction. The a-plane GaN films were characterized by X-ray photoelectron spectroscopy (XPS) to determine carbon contamination from carbonized PR masks in the GaN film bulk. After $Ar^+$ ion etching, XPS spectra indicated that carbon contamination exists only in the surface region. Finally, the heat treatment of carbonized PR masks was used to grow high-quality a-plane GaN films without carbon contamination. This approach showed the promising potential of the ELO process by using a PR mask.

• Bulletin of the Korean Chemical Society
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• 제15권1호
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• pp.79-83
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• 1994

The organometallic chemical vapor deposition of single precursors, $[Me_2Al({\mu}-NHR)]_2\;(R=^iPr,\;^tBu)$, for alumininum nitride thin films has been investigated to evaluate their poroperties as potential precursors. In chemical vapor deposition processes the gas phase products scattered from a Ni(100) substrate were analyzed by mass spectrometry and the deposited films were characterized by X-ray photoelectron spectroscopy (XPS). The optimum temperatures for the formation of AlN films have been found to be between 700 K and 800 K. Carbon contamination of the films seems to be attributed mainly to the methyl groups bonded to the aluminum atoms. It is apparent that $^tBu$ group is better than $^iPr$ group as a substituent on the nitrogen atom of the single precursors for the AlN thin film formation.

• 반도체디스플레이기술학회지
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• 제12권1호
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• pp.29-33
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• 2013

We have fabricated transparent polymer composite films with high thermal emissivity, which can be used for heat dissipation of transparent electronics. PMMA (poly(methyl methacrylate)) solution with high transparency and thermal emissivity is mixed with various fillers (carbon nanotubes (CNTs), aluminum nitride (AlN), or silicon carbide (SiC)) with high thermal conductivity. We have achieved the thermal emissivity as high as 0.94 by the addition of CNTs. Compared with the PMMA film on glass, however, the addition of AlN or SiC is shown to rather decrease the thermal emissivity. It is also observed that the thickness of the PMMA film does not affect its thermal emissivity. To avoid any degradation of the thermal conductivity, therefore, the PMMA film thickness is desirable to be $1{\mu}m$. There also exists a tradeoff between the optical transmittance and thermal conductivity on the selection of the amount of fillers.

• 한국표면공학회지
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• 제39권3호
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• pp.137-141
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• 2006

Process window for infinite etch selectivity of silicon nitride $(Si_3N_4)$ layers to ArF photoresist (PR) was investigated in dual frequency superimposed capacitive coupled plasma (DFS-CCP) by varying the process parameters such as low frequency power $(P_{LF})$, $CH_2F_2$ and $H_2$ flow rate in $CH_2F_2/H_2/Ar$ plasma. It was found that infinite etch selectivities of $Si_3N_4$ layers to the ArF PR on both blanket and patterned wafers can be obtained for certain gas flow conditions. The etch selectivity was increased to the infinite values as the $CH_2F_2$ flow rate increases, while it was decreased from the infinite etch selectivity as the $H_2$ flow rate increased. The preferential chemical reaction of the hydrogen with the carbon in the polymer film and the nitrogen on the $Si_3N_4$ surface leading to the formation of HCN etch by-products results in a thinner steady-state polymer and, in turn, to continuous $Si_3N_4$ etching, due to enhanced $SiF_4$ formation, while the polymer was deposited on the ArF photoresist surface.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.73-73
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• 1999

A large area negative metal ion beam source is developed. Kinetic ion beam of the incident metal ions yields a whole nucleation and growth phenomena compared to the conventional thin film deposition processes. At the initial deposition step one can engineer the surface and interface by tuning the energy of the incident metal ion beams. Smoothness and shallow implantation can be tailored according to the desired application process. Surface chemistry and nucleation process is also controlled by the energy of the direct metal ion beams. Each individual metal ion beams with specific energy undergoes super-thermodynamic reactions and nucleation. degree of formation of tetrahedral Sp3 carbon films and beta-carbon nitride directly depends on the energy of the ion beams. Grain size and formation of polycrystalline Si, at temperatures lower than 500deg. C is obtained and controlled by the energy of the incident Si-ion beams. The large area metal ion source combines the advantages of those magnetron sputter and SKIONs prior cesium activated metal ion source. The ion beam source produces uniform amorphous diamond films over 6 diameter. The films are now investigated for applications such as field emission display emitter materials, protective coatings for computer hard disk and head, and other protective optical coatings. The performance of the ion beam source and recent applications will be presented.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.377-377
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• 2012

Microprocessor technology now relies on copper for most of its electrical interconnections. Because of the high diffusivity of copper, Atomic layer deposition (ALD) $TaN_x$ is used as a diffusion barrier to prevent copper diffusion into the Si or $SiO_2$. Another problem with copper is that it has weak adhesion to most materials. Strong adhesion to copper is an essential characteristic for the new barrier layer because copper films prepared by electroplating peel off easily in the damascene process. Thus adhesion-enhancing layer of cobalt is placed between the $TaN_x$ and the copper. Because, cobalt has strong adhesion to the copper layer and possible seedless electro-plating of copper. Until now, metal film has generally been deposited by physical vapor deposition. However, one draw-back of this method is poor step coverage in applications of ultralarge-scale integration metallization technology. Metal organic chemical vapor deposition (MOCVD) is a good approach to address this problem. In addition, the MOCVD method has several advantages, such as conformal coverage, uniform deposition over large substrate areas and less substrate damage. For this reasons, cobalt films have been studied using MOCVD and various metal-organic precursors. In this study, we used $C_{12}H_{10}O_6(Co)_2$ (dicobalt hexacarbonyl tert-butylacetylene, CCTBA) as a cobalt precursor because of its high vapor pressure and volatility, a liquid state and its excellent thermal stability under normal conditions. Furthermore, the cobalt film was also deposited at various $H_2/NH_3$ gas ratio(1, 1:1,2,6,8) producing pure cobalt thin films with excellent conformality. Compared to MOCVD cobalt using $H_2$ gas as a reactant, the cobalt thin film deposited by MOCVD using $H_2$ with $NH_3$ showed a low roughness, a low resistivity, and a low carbon impurity. It was found that Co/$TaN_x$ film can achieve a low resistivity of $90{\mu}{\Omega}-cm$, a low root-mean-square roughness of 0.97 nm at a growth temperature of $150^{\circ}C$ and a low carbon impurity of 4~6% carbon concentration.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1996년도 The 9th KACG Technical Annual Meeting and the 3rd Korea-Japan EMGS (Electronic Materials Growth Symposium)
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• pp.5-18
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• 1996

The solid state cesium ion source os alumino-silicate based zeolite which contains cerium. The material is an ionic conductor. Cesiums are stably stored in the material and one can extract the cesiums by applying electric field across the electrolyte. Cesium ion bombardment has the unique property of producing high negative ion yield. This ion source is used as the primary source for the production of a negative ion without any gas discharge or the need for a carrier gas. The deposition of materials as an ionic species in the energy range of 1.0 to 300eV is recently recognized as a very promising new thin film technique. This energetic non-thermal equilibrium deposition process produces films by “Kinetic Bonding / Energetic Condensation" mechansim not governed by the common place thermo-mechanical reaction. Under these highly non-equilibrium conditions meta-stable materials are realized and the negative ion is considered to be an optimum paeticle or tool for the purpose. This process differs fundamentally from the conventional ion beam assisted deposition (IBAD) technique such that the ion beam energy transfer to the deposition process is directly coupled the process. Since cesium ion beam sputter deposition process is forming materials with high kinetic energy of metal ion beams, the process provider following unique advantages:(1) to synthesize non thermal-equilibrium materials, (2) to form materials at lower processing temperature than used for conventional chemical of physical vapor deposition, (3) to deposit very uniform, dense, and good adhesive films (4) to make higher doposition rate, (5) to control the ion flux and ion energy independently. Solid state cesium ion beam sputter deposition system has been developed. This source is capable of producing variety of metal ion beams such as C, Si, W, Ta, Mo, Al, Au, Ag, Cr etc. Using this deposition system, several researches have been performed. (1) To produce superior quality amorphous diamond films (2) to produce carbon nitirde hard coatings(Carbon nitride is a new material whose hardness is comparable to the diamond and also has a very high thermal stability.) (3) to produce cesiated amorphous diamond thin film coated Si surface exhibiting negative electron affinity characteristics. In this presentation, the principles of solid state cesium ion beam sputter deposition and several applications of negative metal ion source will be introduced.

• 한국표면공학회지
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• 제36권3호
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• pp.229-233
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• 2003

Boron-Carbon-Nitrogen (B-C-N) system is an attractive ternary material since it has not only an extremely high hardness but also a number of other prominent characteristics such as chemical inertness, elevated melting point, and low thermal expansion. In this paper, the corrosion behavior of B-C-N thin films in aqueous solution was investigated B-C-N films with different composition were deposited on a platinum plate by magnetron sputtering in the thickness range of 150-280 nm. In order to understand effect of pH of solutions, $BC_{2.\;4}N$ samples were immerged in 1M HCl, 1M NaCl, and 1M NaOH solution at 298k, respectively. BCN samples with different carbon contents were exposed to 1M NaOH solutions to investigate effect of chemical composition on corrosion resistance. Corrosion rates of samples were measured by ellipsometry, From results, optical constant of $BC_{2,\;4}N$ films was found to be $N_2=2.110-0.295i$. The corrosion rates of $Bi_{1.\;0}C_{2.\;4}N_{1.\;0}$ films were NaOH>NaCl>HCl in orders. With increasing carbon content in B-C-N films, the corrosion resistance of B-C-N films was enhanced. The lowest corrosion rate was obtained for $B_{1.\;0}C_{4.\;4}N_{1.\;9}$ film.

• 한국재료학회지
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• 제5권7호
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• pp.775-780
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• 1995

MOCVD(Metal-Organic Chemical Vapor Dposition) TiN 박막을 다양한 온도와 압력에서 tetrakis-dimethyl-amino-titanium(TDMAT (Ti[N($CH_3$)$_2$]$_4$))의 자체 열분해와 NH$_3$와의 반응을 사용하여 형성하였다. 비저항은 박막내의 불순물 함량에 의존하였는데 특히 XPS curve fitting 결과 주요 불순물인 탄소와 산소 같은 불순물들이 박막내에서 다양한 침입형화합물을 만들어 박막의 물리적, 전기적 특성에 영향을 준다는 것을 알았다. Metal-organic source만을 사용하여 TiN을 형성할 경우 지름이 0.5$\mu\textrm{m}$이고 aspect ratio가 3:1인 구멍에서 step coverage가 매우 우수하였으나 NH$_3$를 흘림에 따라 step coverage가 감소하는 것이 SEM으로 확인되었는데 이는 각각의 활성화에너지와 관련된 것으로 보인다.