• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2052-2054
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• 2005

TFT-LCD requires to use poly silicon for High resolution and High integration. Thin film make of Poly silicon on the excimer laser-induced crystallization of PECVD(plasma-enhanced chemical vapor deposition)-grown amorphous silicon. In the thin film hydrogen affects to a device performance from bad elements like eruption, void and etc. So dehydrogenation prior to laser exposure was necessary. In this study, use RTP(Rapid Thermal Process) at various temperature from $670^{\circ}C$ to $750^{\circ}C$ and fabricate poly-silicon. it propose optimized RTP window to compare grain size to use poly silicon's SEM pictures and crystallization to analyze Raman curved lines.

• Journal of the Korean Electrochemical Society
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• v.3 no.1
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• pp.19-24
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• 2000

It is increasingly necessary to use poly-Si n's as high resolution and integration of Tn for LCD. Excimer Laser Crystallization (ELC) of a-Si is mainly used as a low temperature process. But the ELC method for the fabrication of poly-Si has the eruption problems associated with hydrogen in the a-Si film. So we need a dehydro-genation process additionally. Hydrogen in a-Si film can degrade the quality of poly-Si film and electrical properties of device due to the hydrogen eruption and voids which occur during the excimer laser annealing. In this study, we propose mesh-type PECVD as the a-Si film deposition method for achieving the low concentration hydrogen. Mesh-type PECVD was found to reduce the hydrogen content substantially. We could obtain a as-deposited a-Si film with hydrogen contents less than $1\%$ at $300^{\circ}C$. We also investigated the behavior by XeCl excimer laser annealing of a-Si fabricated by mesh-type PECVB. As a result, we were able to confirm the broad process window in contrast to the narrow process range typically obtained in ELC. Hydrogen eruption was not observed in poly-Si films after ELC These results suggests that mesh-type PECVD is a viable method to achieve the low hydrogen content a-Si and improve the process windows for ELC.

• Journal of Information Display
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• v.11 no.3
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• pp.109-112
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• 2010

The solid phase compositions and dielectric properties of silicon nitride ($SiN_x$) films prepared using the plasma enhanced chemical vapor deposition (PECVD) technique at a low temperature ($200^{\circ}C$) were studied. Controlling the source gas mixing ratio, R = $[N_2]/[SiH_4]$, and the plasma power successfully produced both silicon-rich and nitrogen-rich compositions in the final films. The composition parameter, X, varied from 0.83 to 1.62. Depending on the film composition, the dielectric properties of the $SiN_x$ films also varied substantially. Silicon-rich silicon nitride (SRSN) films were obtained at a low plasma power and a low R. The photoluminescence (PL) spectra of these films revealed the existence of nano-sized silicon particles even in the absence of a post-annealing process. Nitrogen-rich silicon nitride (NRSN) films were obtained at a high plasma power and a high R. These films showed a fairly high dielectric constant ($\kappa$ = 7.1) and a suppressed hysteresis window in their capacitance-voltage (C-V) characteristics.

• Journal of the Korean Vacuum Society
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• v.21 no.1
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• pp.29-35
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• 2012

The Hydrogenated silicon nitride (SiNx:H) using plasma enhanced chemical vapor deposition is widely used in photovoltaic industry as an antireflection coating and passivation layer. In the high temperature firing process, the $SiN_x:H$ film should not change the properties for its use as high quality surface layer in crystalline silicon solar cells. Initially PECVD-$SiN_x:H$ film trends were investigated by varying the deposition parameters (temperature, electrode gap, RF power, gas flow rate etc.) to optimize the process parameter conditions. Then by varying gas ratios ($NH_3/SiH_4$), the hydrogenated silicon nitride films were analyzed for its optical, electrical, chemical and surface passivation properties. The $SiN_x:H$ films of refractive indices 1.90~2.20 were obtained. The film deposited with the gas ratio of 3.6 (Refractive index=1.98) showed the best properties in after firing process condition. The single crystalline silicon solar cells fabricated according to optimized gas ratio (R=3.6) condition on large area substrate of size $156{\times}156mm$ (Pseudo square) was found to have the conversion efficiency as high as 17.2%. Optimized hydrogenated silicon nitride surface layer and high efficiency crystalline silicon solar cells fabrication sequence has also been explained in this study.

• Korean Journal of Materials Research
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• v.10 no.4
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• pp.282-289
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• 2000

$PbTiO_3$ films were fabricated by electron cyclotron resonance plasma enhanced chemical vapor deposition(ECR-PECVD). Deposition characteristics of $PbTiO_3$films on $RuO_2$ and Pt substrates were investigated with varying the flow rate of metalorganic source and substrate temperature. The residence time of Pb-oxide molecules in much longer on $RuO_2$ than on Pt substrate, while the perovskite nucleation is more difficult on $RuO_2$ than on Pt substrate. Therefore, the process conditions to obtain the single perovskite $PbTiO_3$ phase are more restricted on $RuO_2$ than on Pt substrates. An introduction of Ti-oxide seed layer increases perovskite nucleation density and thus enlarges the process window to obtain the single perovkite phase. The introduction of Ti-oxide seed layer make the PZT film that Ti-components of $PbTiO_3$ are partially substituted with Zr atoms have single perovskite phase for the wide range of Zr/(Zr+Ti) concentration ratios.