The surface of carbon films deposited with inverted plasma fireballs is analysed in this paper. Measurements were conducted with Raman spectroscopy, atomic force microscopy and nanoindentation. The latter was used to obtain Young’s modulus as well as Martens and Vickers hardness. The roughness of the film was measured by atomic force microscopy and its thickness was measured. It was shown with Raman spectroscopy that the films are homogeneous in terms of atomic composition and layer thickness over an area of about 125 × 125 mm. Furthermore, it was demonstrated that inverted plasma fireballs are a viable tool for obtaining homogeneous, large area carbon films with rapid growth and very little energy consumption. The obtained films show very low roughness.

DLC has been attractive as semiconductor materials for solar cell due to its biological friendliness, flexible microstructures, and especially its tunable band gap. In order to fabricate high-efficiency multiband gap solar cell, it is important to control the sp3/ sp2 bonds ratio of DLC film corresponding to optical band gap (Eg). There are many references reporting the relations among the fabrication conditions, Eg, sp3/ sp2, and ID/ IG. However, a more comprehensive database is needed for controllable fabrication. Especially, the quantitative relationship of sp3/ sp2 ratio to Eg of DLC film by PECVD is unclear. In this paper, 36 sets of DLC films were fabricated by RF-PECVD. Characterization methods of XPS, Raman spectroscopy, and IR absorption have been used to determine the sp3/ sp2 ratio of DLC films. UV/visible light absorption method has applied to evaluate Eg. The Eg obtained is in the range 1.45–3.0 eV. Our results agree well with the references. The XPS spectra gives a linear relationship as Eg = − 0.161 (± 0.136) + 26.095 (± 1.704) · {sp3 (XPS)/sp2}, the Raman spectra shows a linear function that Eg = 1.327 (± 0.046) + 0.428 (± 0.036) · (ID/IG), as well as the FTIR analysis demonstrates that Eg = − 0.492 (± 0.093) + 0.464 (± 0.044) · {sp3 (FTIR)/sp2}.

Various surface colors are predicted and implemented using the interference color generated by controlling the thickness of nano-level diamond like carbon (DLC) thin film. Samples having thicknesses of up to 385 nm and various interference colors are prepared using a single crystal silicon (100) substrate with changing processing times at low temperature by plasma-enhanced chemical vapor deposition. The thickness, surface roughness, color, phases, and anti-scratch performance under each condition are analyzed using a scanning electron microscope, colorimeter, micro-Raman device, and scratch tester. Coating with the same uniformity as the surface roughness of the substrate is possible over the entire experimental thickness range, and more than five different colors are implemented at this time. The color matched with the color predicted by the model, assuming only the reflection mode of the thin film. All the DLC thin films show constant D/G peak fraction without significant change, and have anti-scratch values of about 19 N. The results indicate the possibility that nano-level DLC thin films with various interference colors can be applied to exterior materials of actual mobile devices.

This paper presents a Raman spectroscopy study of the influence of methane flow on the micro-tribological behavior of diamond-like carbon coatings deposited with an industrial plasma-enhanced chemical vapor deposition system. Results have shown a direct relationship between the methane flow and thickness of the coatings. The analysis of the Raman spectra and deposition parameters allowed establishing the influence of H content with the methane flow, the disorder level and estimation of the sp3 fraction on the carbon coatings. The micro-tribology tests showed a strong dependence of the wear resistance and hardness with Raman parameters. The coating deposited at 72-sccm methane flow presented a thickness of 1.7 μm and a sp3 fraction of 0.33. This sp3 fraction gave rise to a hardness of 24 GPa and an excellent wear resistance of 3.3 × 10–6 mm3 N−1 mm−1 for this DLC coating. Wear tests showed a swelling in the wear profiles on this coating, which was associated with the occurrence of a re-hybridization process.

We examined the characteristics of indium tin zinc oxide (ITZO) thin film transistors (TFTs) on polyimide (PI) substrates for next-generation flexible display application. In this study, the ITZO TFT was fabricated and analyzed with a SiOx/ SiNx gate insulator deposited using plasma enhanced chemical vapor deposition (PECVD) below 350℃. X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS) results revealed that the oxygen vacancies and impurities such as H, OH and H2O increased at ITZO/gate insulator interface. Our study suggests that the hydrogen related impurities existing in the PI and gate insulator were diffused into the channel during the fabrication process. We demonstrate that these impurities and oxygen vacancies in the ITZO channel/gate insulator may cause degradation of the electrical characteristics and bias stability. Therefore, in order to realize high performance oxide TFTs for flexible displays, it is necessary to develop a buffer layer (e.g., Al2O3) that can sufficiently prevent the diffusion of impurities into the channel.

We investigated the nanostructural, chemical and optical properties of nc-Si:H films according to deposition conditions. Plasma enhanced chemical vapor deposition(PECVD) techniques were used to produce nc-Si:H thin films. The hydrogen dilution ratio in the precursors, [SiH4/H2], was fixed at 0.03; the substrate temperature was varied from room temperature to 600˚C. By raising the substrates temperature up to 400˚C, the nanocrystalite size was increased from ~2 to ~7 nm and the Si crystal volume fraction was varied from ~9 to ~45% to reach their maximum values. In high-resolution transmission electron microscopy(HRTEM) images, Si nanocrystallites were observed and the crystallite size appeared to correspond to the crystal size values obtained by X-ray diffraction(XRD) and Raman Spectroscopy. The intensity of high-resolution electron energy loss spectroscopy(EELS) peaks at ~99.9 eV(Si L2,3 edge) was sensitively varied depending on the formation of Si nanocrystallites in the films. With increasing substrate temperatures, from room temperature to 600˚C, the optical band gap of the nc-Si:H films was decreased from 2.4 to 1.9 eV, and the relative fraction of Si-H bonds in the films was increased from 19.9 to 32.9%. The variation in the nanostructural as well as chemical features of the films with substrate temperature appears to be well related to the results of the differential scanning calorimeter measurements, in which heat-absorption started at a substrate temperature of 180˚C and the maximum peak was observed at ~370˚C.

본 연구에서는, 반도체, LCD 공정에서 금속막을 증착하기 위하여 PECVD장비에 화재, 폭발 위험성과 독성을 가진 Silane가스를 사용하게 되는 장비인 gas cabinet, pipeline, VMB(Valve manifold box), MFC(mass flow controller)장비 등, 전반적인 시스템에 대하여 영국 HES의 ALARP개념을 도입하여 위험성 평가를 실시하여 문제점을 도출하고 대책을 강구 하는데 목적이 있고, 여러 가지 문제점중

The development of low-k materials is essential for modern semiconductor processes to reduce the cross-talk, signal delay and capacitance between multiple layers. The effect of the CH4 concentration on the formation of SiOC(-H) films and their dielectric characteristics were investigated. SiOC(-H) thin films were deposited on Si(100)/SiO2/Ti/Pt substrates by plasma-enhanced chemical vapor deposition (PECVD) with SiH4, CO2 and CH4 gas mixtures. After the deposition, the SiOC(-H) thin films were annealed in an Ar atmosphere using rapid thermal annealing (RTA) for 30min. The electrical properties of the SiOC(-H) films were then measured using an impedance analyzer. The dielectric constant decreased as the CH4 concentration of low-k SiOC(-H) thin film increased. The decrease in the dielectric constant was explained in terms of the decrease of the ionic polarization due to the increase of the relative carbon content. The spectrum via Fourier transform infrared (FT-IR) spectroscopy showed a variety of bonding configurations, including Si-O-Si, H-Si-O, Si-(CH3)2, Si-CH3 and CHx in the absorbance mode over the range from 650 to 4000 cm-1. The results showed that dielectric properties with different CH4 concentrations are closely related to the (Si-CH3)/[(Si-CH3)+(Si-O)] ratio.

rf PECVB법을 이용하여 붕규산 유리 기판 위에 diamond like carbon(DLC) 박막을 증착하였다. 메탄(CH4)-수소(H2) 혼합 가스를 전구체 가스로 사용하였다. DLC 박막의 형상, 구조 및 광학적 특성은 SEM, 라만 및 UV 스펙트럼으로 분석하였다. 증착 속도는 혼합 가스의 수소 농도에 따라 증가하다가, 혼합 가스 유량이 25 sccm 이상에서는 일정하게 되었다. UV스펙트럼으로 계산한 박막의 optical band gap은 증착 시간과 DC serf bias의 증가에 따라 감소하는 경향을 나타냈으나, 수소함량에 의해서는 거의 영향이 없었다. 박막의 투과율에 가장 큰 영향을 미치는 인자는, 특히 자외선 영역과 가시광선 영역에서, bias 전압이었다.

플라즈마 화학증착법을 이용하여 Corning glass 1737 기판에 안티몬 도핑 산화주석 박막을 증착하였다. 플라즈만 화학증착시 반응변수에 따른 박막의 결정상 및 형성된 표면거칠기에 대하여 XRD와 AFM을 이용하여 검토하였다. 반응온도 450˚C, 유입가스비 R[PSbClPSnCl4]=1.12, r.f. power 30W에서 비교적 결정성이 뛰어난 박막을 얻을 수 있었다. 화학증착법(TCVD)에 비해 플라즈마 열화학증착법(PECVD)으로 얻은 박막의 표현형상이 보다 균일하였다. 안티몬 도핑농도가 증가할수록, 증착온고가 낮을수록, 증착두께가 작을수록 박막의 표면거칠기가 보다 감소하였다.

일반적으로 TFT(thin film transistor)의 유전체막으로 실리콘 질화막(Si3N4)이나 실리콘 산화막(SiO2)을 200-300˚C의 온도에서 증착을 하게 되는데 본 연구에서는 비정질 실리콘과 유전체막 사이의 계면 특성 특히 계면의 거칠기를 향상시키기 위해서 기존의 증착법이 아니라 비정질 실리콘(a-Si:H)과 산소 ECR 플라즈마의 반응에 의한 산화 막의 성장법을 시도했는데, 이때 기판은 의도적으로 가열하지 않았으며 특히 본 연구에서는 기존의 시도와는 달리 ECR 플라즈마를 형성할 때 마이크로파 전력에 pulse를 가하는 방법을 최초로 시도했고, 계면에 불순물의 혼입을 최대한으로 줄이기 위해서 진공을 파괴하지 않은 상태로 산화막을 연속적으로 성장시키는 방법을 이용했다. Pulse를 가했을 경우에는 pulse를 가하지 않은 경우에 비해서 화학양론적 측면, 유전상수, 산화막의 표면 평탄도 등에서 우수한 산화막이 성장했으며, 특히 비정질 실리콘과 유전체막 사이의 계면 특성을 반영하는 산화막의 표면 평탄도가 1/3정도로 획기적으로 줄어들었다.

본 연구에서는 rf PECVD(13.56MHz)법을 이용하여 CH4가스에 소량의 보조가스(O2와 N2)를 혼합하여 a-C:H 박막을 얻었다. 이렇게 얻어진 박막의 증착속도는 rf power 증가에 따라서 증가하다가 200W에서는 다시 감소하였으며, 산소와 질소가스의 유량이 증가함에 따라 감소하였다. FT-IR분석으로 계산된 박막내의 수소함량은 rf power 증가와 산소 및 질소첨가량의 증가에 따라 감소하였다. 산소가스 첨가 시에는 C=O 결합이 생성되며, 질소가스 첨가 시에는 C=N 결합이 생성됨을 FT-IR 분석을 통하여 알 수 있었다. 이와 같이 산소와 질소를 보조가스로 첨가할 경우에 스퍼터링 효과로 박막내의 수소함량 감소와 더불어 a-C:H 박막의 구조 변화를 일으킬 수 있을 것으로 생각된다. Raman 분석결과 산소와 질소를 첨가함에 따라서 I(sub)D/I(sub)G비가 증가하였고, D line과 G line의 위치가 높은 파수 쪽으로 이동하였으며, D line의 폭은 넓어지는 반면에 G line의 폭은 감소됨을 보였다. 이것은 산소와 질소의 첨가로 박막내의 수소함량 감소, 결합각의 disorder 감소 및 micro-crystallite 흑연의 형성에 의한 것이라고 판단된다.

PECVD(Plasma enhanced chemical vapor deposition)을 이용하여 yttria-stabilized zirconia(YSZ) 박막을 제조하였다. 반응물질로 금속유기화합물을 Zr[TMHD]4와 Y[TMHD]3그리고 산소를 사용하였으며, 증착온도는 425˚C, rf power는 0~100W까지 적용하였다. YSZ 박막은 (200)면이 기판에 평행한 입벙정상 구조를 가졌으며, 1시간 내에 1μm 두께를 형성하였다. EDX에 의한 막의 성분분석 결과로부터 환산된 박막내의 Y2O3의 함량은 0-36%의 범위였다. 버블러의 온도 및 운반기체의 유량이 증가함에 따라 박막의 두께 역시 비례하여 증가하였는데, 이는 precursor의 flux 증가로 인한 박막내의 Y2O3의 함량증가에 의한 것이었다. Zr 및 Y, O는 박막의 두께에 따라 일정한 조성비를 나타내었다. 운반기체를 Ar로 하였을 때 1000Å이하의 크기를 갖는 YSZ 입자들이 column 모양으로 기판에 수직하게 성장하였으며, 운반기체가 He인 경우에도 column 모양으로 성장하였으며 입도가 1000~2000Å으로 Ar의 경우보다 조대해졌다. XRD 분석결과 Y2O3의 함량이 증가함에 따라 YSZ의 격자상수 값이 약간씩 증가하였다. 이는 박막 전반에 걸쳐 형성된 균열에 의해 격자변형으로 인해 발생한 응력을 완화시켰지 때문이다.