• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.253-253
• /
• 2012

Low temperature SiOx film process has being required for both silicon and oxide (IGZO) based low temperature thin film transistor (TFT) for application of flexible display. In recent decades, from low density and high pressure such as capacitively coupled plasma (CCP) type plasma enhanced chemical vapor deposition (PECVD) to the high density plasma and low pressure such as inductively coupled plasma (ICP) and electron cyclotron resonance (ECR) have been used to researching to obtain high quality silicon oxide (SiOx) thin film at low temperature. However, these plasma deposition devices have limitation of controllability of process condition because process parameters of plasma deposition such as RF power, working pressure and gas ratio influence each other on plasma conditions which non-leanly influence depositing thin film. In compared to these plasma deposition devices, neutral beam assisted chemical vapor deposition (NBaCVD) has advantage of independence of control parameters. The energy of neutral beam (NB) can be controlled independently of other process conditions. In this manner, we obtained NB dependent high crystallized intrinsic and doped silicon thin film at low temperature in our another papers. We examine the properties of the low temperature processed silicon oxide thin films which are fabricated by the NBaCVD. NBaCVD deposition system consists of the internal inductively coupled plasma (ICP) antenna and the reflector. Internal ICP antenna generates high density plasma and reflector generates NB by auger recombination of ions at the surface of metal reflector. During deposition of silicon oxide thin film by using the NBaCVD process with a tungsten reflector, the energetic Neutral Beam (NB) that controlled by the reflector bias believed to help surface reaction. Electrical and structural properties of the silicon oxide are changed by the reflector bias, effectively. We measured the breakdown field and structure property of the Si oxide thin film by analysis of I-V, C-V and FTIR measurement.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2007.04a
• /
• pp.87-88
• /
• 2007

나노 다결정 실리콘 박막 증착을 하기 위해서 현재 정전결합플라즈마(CCP, Capacitively Coupled Plasma)를 이용한 PECVD(Plasma Enhanced Chemical Vapor Deposition) 공정에 관한 여구가 활발히 이루어지고 있다. 유도결합플라즈마는(ICP, Inductively Coupled Plasma) 정전결합플라즈마보다 플라즈마 밀도가 높고 파워전달 효율이 좋은 것으로 알려져 있으나 대면적가 어려워 기판이 큰 TFT-LCD로는 많이 연구되고 있지 않다. 본 연구는 유도결합플라즈마를 위해 내장형 multiple U-type 선형 안테나를 이용하여 나노 다결정 실리콘 박막을 증착하여 그 특성을 분석하였다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.08a
• /
• pp.310-311
• /
• 2011

Dual-frequency (DF) capacitively coupled plasmas (CCP) are used to separately control the mean ion energy and flux at the electrodes [1]. This separate control in capacitively coupled radio frequency discharges is one of the most important issues for various applications of plasma processing. For instance, in the Plasma Enhanced Chemical Vapor Deposition processes such as used for solar cell manufacturing, this separate control is most relevant. It principally allows to increase the ion flux for high deposition rates, while the mean ion energy is kept constant at low values to prevent highly energetic ion bombardment of the substrate to avoid unwanted damage of the surface structure. DF CCP can be analyzed in a fashion similar to single-frequency (SF) driven with effective parameters [2]. It means that DF CCP can be converted into SF CCP with effective parameters such as effective frequency and effective current density. In this study, comparison of DF CCP and its converted effective SF CCP is carried out through particle-in-cell/Monte Carlo (PIC-MCC) simulations. The PIC-MCC simulation shows that DF CCP and its converted effective SF CCP have almost the same plasma characteristics. In DF CCP, the negative resistance arises from the competition of the effective current and the effective frequency [2]. As the high-frequency current increases, the square of the effective frequency increases more than the effective current does. As a result, the effective voltage decreases with the effective current and it leads to an increase of the ion flux and a decrease of the mean ion energy. Because of that, the negative resistance regime can be called the preferable regime for solar cell manufacturing. In this preferable regime, comparison of DF (13.56+100 or 200 MHz) CCP and SF (60 MHz) CCP with the same effective current density is carried out. At the lower effective current density (or at the lower plasma density), the mean ion energy of SF CCP is lower than that of DF CCP. At the higher effective current density (or at the higher plasma density), however, the mean ion energy is lower than that of SF CCP. In this case, using DF CCP is better than SF CCP for solar cell manufacturing processes.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.227.2-227.2
• /
• 2015

세포를 부착하는 기술은 세포를 배양하기 위한 가장 기초적이며 중요한 기술이다. 세포 부착기술은 대상물과 세포 간의 다양한 생물학적, 물리화학적 연관 관계가 있으나 세포와 부착 대상물 간의 복잡한 상호작용 때문에 완벽히 예측하기는 어렵다. 우리는 이 연구에서 siloxane 성분을 포함하고 있는 전구체인 tetrakis(trimethylsilyloxy)silane과 hydro-carbon을 포함하고 있는 전구체인 cyclohexane을 혼합하여 플라즈마 중합 박막을 만들고 그 박막에서의 mouse embryonic fibroblast cells과 bovine aortic endothelial cell 부착의 정도를 확인하였다. 플라즈마 중합 박막을 제작하기 위해 capacitively coupled plasma chemical vapor deposition system을 사용하였고 carrier gas로는 Ar을 사용하였다. Plasma RF power는 13.56MHz 70W를 사용하였다. Bubbler에서 기화된 전구체를 포함하고 있는 Ar carrier gas가 process chamber에서 혼합되고 두 전구체의 비율을 조절하기 위해 carrier gas를 0 에서 150sccm으로 변화시켜 플라즈마 중합 박막을 제작하였다. 플라즈마 중합 박막의 화학적 조성은 Fourier transform infrared absorption spectroscopy와 X-ray photoelectron spectroscopy를 이용하여 측정하였고, 생물학적 세포 부착 정도는 현미경을 통해 관찰하였다. 또한, 물과 박막의 접촉각(Water contact angle)을 측정함으로써 본 박막과 세포 부착에서의 친, 소수성의 연관성을 확인하였다. Tetrakis(trimethylsilyloxy)silane를 전구체를 사용한 박막에서 세포 부착 억제 표면특성이 관찰되었고, 주입되는 cyclohexane 비율이 늘어날수록 세포부착 가능한 표면 특성을 보였다. 결과적으로, 전구체인 tetrakis(trimethylsilyloxy)silane와 cyclohexane의 비율을 조절함으로써 세포의 부착정도를 제어할 수 있음을 확인하였다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.399-399
• /
• 2010

Polyethylene glycol(PEG)은 강력한 단백질 및 세포흡착 억제력을 가지고 있어 다양한 생물학적 연구에 사용되고 있으나, 기판과의 결합력이 무척 약해 기판 위에 박막을 형성하기가 매우 어렵다는 문제점이 있다. 이번 연구에서는 capacitively-coupled plasma chemical vapor deposition(CCP-CVD)를 이용하여 PEG를 유리 기판 위에 플라즈마 중합하여 plasma-polymerized PEG(PP-PEG) 기판을 만들었다. PP-PEG 박막은 FT-IR, XPS, ToF-SIMS 분석을 통하여 PEG와 매우 유사한 화학적 조성을 가지고 있음을 확인할 수 있었다. 또한 PP-PEG 기판은 photolithography 방법을 이용하여 표면에 photoresist를 패턴한 뒤 아민작용기를 가지는 plasma-polymerized ethylenediamine (PPEDA)를 증착하여 표면이 amine/PEG로 패턴화된 박막 기판을 만들었다. 패턴된 기판에 단백질 및 세포를 고정화하였을 때, 아민 작용기가 노출된 부분에만 고정화가 나타나고 PP-PEG 영역에는 단백질 및 세포의 흡착이 효율적으로 억제되는 것을 형광측정 및 ToF-SIMS chemical imaging 방법을 이용하여 확인하였다. 이러한 바이오칩 제작기술은 단백질 및 세포 칩을 포함한 여러 분야에서 폭넓게 응용될 수 있을 것으로 기대된다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.1568-1570
• /
• 2009

Nanocrystalline silicon thin films were deposited using an internal-type inductively coupled plasma-chemical vapor deposition at room temperature by varying the bias power to the substrate and the structural characteristics of the deposited thin film were investigated. The result showed that the crystalline volume fraction was decreased with the increase of bias power. At the low bias power range of 0~60 W, the compress stress in the deposited thin film was in the range of -34 ~ -77 Mpa which is generally lower than the residual stress observed for the nanocrystalline silicon thin films deposited by capacitively coupled plasma.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.221-221
• /
• 2014

The present work proposes an improved numerical simulator for design and modification of large area capacitively coupled plasma (CCP) processing chamber. CCP, as notoriously well-known, demands the tremendously huge computational cost for carrying out transient analyses in realistic multi-dimensional models, because electron dissociations take place in a much smaller time scale (${\Delta}t{\approx}10-8{\sim}10-10$) than time scale of those happened between neutrals (${\Delta}t{\approx}10-1{\sim}10-3$), due to the rf drive frequencies of external electric field. And also, for spatial discretization of electron flux (Je), exponential scheme such as Scharfetter-Gummel method needs to be used in order to alleviate the numerical stiffness and resolve exponential change of spatial distribution of electron temperature (Te) and electron number density (Ne) in the vicinity of electrodes. Due to such computational intractability, it is prohibited to simulate CCP deposition in a three-dimension within acceptable calculation runtimes (<24 h). Under the situation where process conditions require thickness non-uniformity below 5%, however, detailed flow features of reactive gases induced from three-dimensional geometric effects such as gas distribution through the perforated plates (showerhead) should be considered. Without considering plasma chemistry, we therefore simulated flow, temperature and species fields in three-dimensional geometry first, and then, based on that data, boundary conditions of two-dimensional plasma discharge model are set. In the particular case of SiH4-NH3-N2-He CCP discharge to produce deposition of SiNxHy thin film, a cylindrical showerhead electrode reactor was studied by numerical modeling of mass, momentum and energy transports for charged particles in an axi-symmetric geometry. By solving transport equations of electron and radicals simultaneously, we observed that the way how source gases are consumed in the non-isothermal flow field and such consequences on active species production were outlined as playing the leading parts in the processes. As an example of application of the model for the prediction of the deposited thickness uniformity in a 300 mm wafer plasma processing chamber, the results were compared with the experimentally measured deposition profiles along the radius of the wafer varying inter-electrode gap. The simulation results were in good agreement with experimental data.

• Journal of information and communication convergence engineering
• /
• v.9 no.2
• /
• pp.217-219
• /
• 2011

As silicon devices shrink and their density increases, the low dielectric constant materials instead of $SiO_2$ film is required. SiOC film as low-k films was deposited by the capacitively coupled plasma chemical vapor deposition and then annealed at $300{\sim}500^{\circ}C$ to find out the properties of the dependence on the temperature and polarity. This study researched the dielectric constant using by the structure of the metal/SiOC film/p-Si, chemical shift, thickness, refractive index and hardness. The trend of reflective index was inverse proportioned the thickness, but the dielectric constant was proportioned it. The dielectric constant decreased with decreasing the thickness and the increment of the refractive index.

• Transactions on Electrical and Electronic Materials
• /
• v.14 no.6
• /
• pp.329-333
• /
• 2013

SiOC films were prepared by capacitively coupled plasma chemical vapor deposition, and the correlation between the binding energy by X-ray photoelectron spectroscopy and Arrhenius equation for ionization energy was studied. The ionization energy decreased with increase of the potential barrier, and then the dielectric constant also decreased. The binding energy decreased with increase of the potential barrier. The dielectric constant and electrical characteristic of SiOC film was obtained by Arrhenius equation. The dielectric constant of SiOC film was decreased by lowering the polarization, which was made from the recombination between opposite polar sites, and the dissociation energy during the deposition. The SiOC film with the lowest dielectric constant had a flat surface, which depended on how carbocations recombined with other broken bonds of precursor molecules, and it became a fine cross-linked structure with low ionization energy, which contributed to decreasing the binding energy by Si 2p, C 1s electron orbital spectra and O 1s electron orbital spectra. The dielectric constant after annealing decreased, owing to the extraction of the $H_2O$ group, and lowering of the polarity.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.08a
• /
• pp.246-246
• /
• 2010

As the trench width in the interconnect technology decreases down to nano-scale below 50 nm, superconformal gap-filling process of Cu becomes very critical for Cu interconnect. Obtaining superconfomral gap-filling of Cu in the nano-scale trench or via hole using MOCVD is essential to control nucleation and growth of Cu. Therefore, nucleation of Cu must be suppressed near the entrance surface of the trench while Cu layer nucleates and grows at the bottom of the trench. In this study, suppression of Cu nucleation was achieved by treating the Ru barrier metal surface with capacitively coupled hydrogen plasma. Effect of hydrogen plasma pretreatment on Cu nucleation was investigated during MOCVD on atomic-layer deposited (ALD)-Ru barrier surface. It was found that the nucleation and growth of Cu was affected by hydrogen plasma treatment condition. In particular, as the plasma pretreatment time and electrode power increased, Cu nucleation was inhibited. Experimental data suggests that hydrogen atoms from the plasma was implanted onto the Ru surface, which resulted in suppression of Cu nucleation owing to prevention of adsorption of Cu precursor molecules. Due to the hydrogen plasma treatment of the trench on Ru barrier surface, the suppression of Cu nucleation near the entrance of the trenches was achieved and then led to the superconformal gap filling of the nano-scale trenches. In the case for without hydrogen plasma treatments, however, over-grown Cu covered the whole entrance of nano-scale trenches. Detailed mechanism of nucleation suppression and resulting in nano-scale superconformal gap-filling of Cu will be discussed in detail.