• Bulletin of the Korean Chemical Society
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• v.11 no.3
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• pp.214-220
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• 1990

We have studied the Infrared Multiphoton Dissociation (IRMPD) of 1-bromo-3-chloropropane by using the pulsed $CO_2$ laser. The product yields and the HCl/HBr branching ratios in IRMPD of $BrCH_2CH_2CH_2Cl$ are studied under the focused beam geometry as a function of buffer gas (He) pressure, laser energy, and photolysing wavelength. It is observed that the total dissociation yield has a laser energy dependence of 1.8-2.0 power order and the branching ratio is very slightly dependent on the pulse energy for the laser lines employed. The dependences of total dissociation yield and branching ratio on the buffer gas pressures show that the dissociation yield monotonically decreases and the branching ratio slightly decreases with the increase of the buffer gas pressure. The Energy-Grained Master Equation (EGME) was applied to explain the laser pulse energy and the buffer gas pressure(He) dependence of the dissociation yield and the branching ratio.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.24.2-24.2
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• 2007

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.5
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• pp.353-357
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• 2010

Recently, silicon etching have received much attention for display industry, nano imprint technology, silicon photonics, and MEMS application. After the etching process, removing of etch mask and residue of sidewall is very important. The investigation of the etched mask removing was carried out by using the ashing, HF dipping and acid cleaning process. Experiment shows that oxygen component of reactive gas and photoresist react with silicon and converting them into the mask fence. It is very difficult to remove by using ashing or acid cleaning process because mask fence consisted of Si and O compounds. However, dilute HF dipping is very effective process for SiOx layer removing. Finally, we found optimized condition for etched mask removing.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.244-244
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• 1999

Liquid Crystal Displays(LCDs) 투명성 전도막으로 사용하는 Indium Tin Oxide (ITO)의 고밀도 식각특성을 조사하였다. 특히 ITO식각의 경우, pixel electrode 전극에서 사용되는 underlayer인 SiO2, Si3N4와의 최적의 선택비를 얻는데 중점을 두고 있다. 따라서 본 실험에서는 Inductively Coupled Plasma(ICP)를 이용하여 source power, gas combination, bias voltage, pressure 및 기판온도에 따른 ITO의 식각 특성과 이의 underlayer인 SiO2, Si3N4와의 선택비를 조사하였다. Ar과 CH4를 주된 식각가스로서 사용하였으며 첨가가스로는 O2와 HBr를 사용하였다. ITO의 식각특성을 이해하기 위하여 Quadruple Mass Spectrometry(QMS), Optical emission spectroscopy(OES) 이용하였으며, 식각된 sample의 잔류물을 조사하기 위하여 X-ray photoelectron spectroscopy(XPS)를 이용하여 분석하였다. Ar gas에 적정량의 CH4 혼합이 순수한 Ar 가스로 식각한 경우에 비하여 ITO와 SiO2, Si3N4의 선택비가 높았으며, 더 높은 식각 선택비를 얻기 위하여 Ar/CH 분위기에서 첨가가스 O2, HBr을 사용하였다. Source power 및 bias 증가에 따라 ITO의 식각률은 증가하나, underlayer와의 선택비는 감소함을 보였다. 본 실험에서 측정된 ITO의 high 식각률은 약 1500$\AA$/min이며, SiO2, Si3N4와의 high selectivity는 각각 7:1, 12:1로 나타났다. ITO의 etchrate 및 선택비는 source power, bias, pressure, CH 가스첨가에 의존하였지만 기판온도에는 큰 변화가 없음을 관찰하였다. 또한 적정량의 가스조합으로 식각된 시편의 잔류물을 줄일 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.245-246
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• 2008

고밀도 트렌치 공정을 위해 HBr 가스를 주로하고 $CF_4$, $SiF_4$, $NF_3$, He-$O_2$ 등을 첨가 가스로 이용하여 트렌치 공정을 하였다. 트렌치 공정시 첨가가스 비에 따라 트렌치 형상이 다양하게 되었다. 이러한 형상은 트렌치 소자 제조시 트렌치 내부를 채울 경우 여러 가지 어려움이 발생되는데, 특히 트렌치 내부가 잘 채워지지 않고 void가 생길 경우 소자의 신뢰성에 많은 영향을 미칠 수 있다. 본 연구에서는 고밀도 트렌치를 병렬로 형성한 후 형성된 트렌치 내부를 잘 채울수 있는 고밀도 트렌치 공정을 연구하였다. 트렌치 형성시 HBr을 주가스로 하고, $NF_3$, $CF_4$, $SiF_4$ 를 비율을 각각 59:27:7:7로 했을 때 수십만 트렌치 형성 각도가 약 $89^{\circ}$로 매우 좋은 형상을 얻었다.

• Applied Chemistry for Engineering
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• v.20 no.1
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• pp.99-103
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• 2009

HBr and $O_2$ in $Cl_2$ gas ambient for the high density plasma gate etching has been used to increase the performance of gate electrode in semiconductor devices. When an un-doped amorphous silicon layer was used for a gate electrode material, the notching profile was observed at the outer sidewall foot of the outermost line. This phenomenon can be explained by the electron shading effect: i.e., electrons are captured at the photoresist sidewall while ions pass through the photoresist sidewall and reach the oxide surface at a narrowly spaced pattern during the over etch step. The potential distribution between gate lines deflects the ions trajectory toward the gate sidewall. In this study, an appropriate mechanism was proposed to explain the occurrence of notching in the gate electrode of un-doped amorphous silicon.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1527-1532
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• 2007

We have evaluated the toxicity of interior materials for the railway passenger car by checking the release of $CO_2$, CO, NOx, SO2, HCl, HF, HBr, HCN. The NOx is one of the most effective for the determination of Toxic Index R value. It is generally known that the mechanism of thermal NOx generation without the Interior Material nitrogen source. This study started from the idea to check the NOx difference according to the furnace temperature. But from the results, it was revealed that NOx is not so sensitive for the furnace temperature in case of solid burning. Other gases such as HCN, CO were more changeable to the furnace Temp. We reported the test result as for toxicity index r(x).

• Journal of the Korean institute of surface engineering
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• v.32 no.2
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• pp.83-92
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• 1999

GaN etching was performed using planar inductively coupled $Cl_2$-based plasmas and the effects of main process parameters on the characteristics of the plasmas and their relations to GaN etch rates were studied. Also, the GaN etch mechanism was investigated using a Langmuir probe and optical emission spectroscopy (OES) during the etching, and X-ray photoelectron spectroscopy (XPS) of the etched surfaces. The GaN etch rates increased with the increase of chlorine radical density and ion energy, and a vertical etch profile haying the etch rate close to 4000 $\AA$/min could be obtained. The addition of 10% Ar to $Cl_2$ gas increased the GaN etch rate and the addition of Ar (more than 20%) and HBr generally reduced the GaN etch rate. The GaN etch rate appeared to be more affected by the chemical reaction between Cl radicals and GaN compared to the physical sputtering itself under the sufficient ion bombardments to break GaN bonds.

• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.490-495
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• 1999

In 0.18 $\mu \textrm m$ LOGIC device, the etch rate of NMOS polysilicons is different from that of PMOS polysilicons due to the state of polysilicon to manufacture gate line. To control the etch profile, we tested the ratio of $Cl_2$/HBr gas and the total chamber pressure, and also we reduced Back He pressure to get the vertical profile. In the case of manufacturing the gate photoresist line, we used Bottom Anti-Reflective Coating (BARC) to protect refrection of light. As a result we found that $CF_4O_2$ gas is good to etch BARC, because of high selectivity and good photoresist line profile after etching BARC. in the results of the characterization of plasma damage to the antenna effect of gate oxide, NO type thin film(growing gate oxide in 0, ambient followed by an NO anneal) is better than wet type thin film(growing gate oxide in $0_2+H_2$ ambient).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.7
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• pp.713-717
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• 2004

In this study, the etched trench properties including cross-sectional profile, surface roughness, and crystalline defects were investigated depending on the various silicon etching and additive gases, For the case of HBr$He-O_2SiF_4$ trench etching gas mixtures, the excellent trench profile and minimum defects in the silicon trench were achieved. Due to the residual oxide film grown by the additive oxygen gas, which acts as a protective layer during trench etching, the undercut and defects generation in the trench were suppressed. To improve the electrical characteristics of trench gate, the hydrogen annealing process after trench etching was also adopted. Through the hydrogen annealing, the trench corners might be rounded by the silicon atomic migration at the trench corners having high potential. The rounded trench corner can afford to reduce the gate electric field and grow a uniform gate oxide. As a result, dielectric strength and TDDB characteristics of the hydrogen annealed trench gate oxide were remarkably increased compared to the non-hydrogen annealed one.