• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1038-1041
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• 2003

In the paper, we investigated silicon surface microstructures formed by reactive ion etching in hollow cathode system. Wet anisotropic chemical etching technique use to form random pyramidal structure on <100> silicon wafers usually is not effective in texturing of low-cost multicrystalline silicon wafers because of random orientation nature, but High density hollow cathode plasma system illustrates high deposition rate, better film crystal structure, improved etching characteristics. The etched silicon surface is covered by columnar microstructures with diameters form 50 to 100nm and depth of about 500nm. We used $SF_{6}$ and $O_{2}$ gases in HCP dry etch process. This paper demonstrates very high plasma density of $2{\times}10^{12}$ $cm^{-3}$ at a discharge current of 20 mA. Silicon etch rate of 1.3 ${\mu}s/min$. was achieved with $SF_{6}/O_{2}$ plasma conditions of total gas pressure=50 mTorr, gas flow rate=40 sccm, and rf power=200 W. Our experimental results can be used in various display systems such as thin film growth and etching for TFT-LCDs, emitter tip formations for FEDs, and bright plasma discharge for PDP applications. In this paper we directed our study to the silicon etching properties such as high etching rate, large area uniformity, low power with the high density plasma.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.159-162
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• 2002

Ferroelectric $YMnO_{3}$ thin films were etched with $Ar/Cl_{2}$ and $CF_{4}/Cl_{2}$ inductivly coupled plasma (ICP). The maximum etch rate of $YMnO_{3}$ thin film was $300{\AA}/min$ at a $Ar/Cl_{2}$ gas mixing ratio of 2/8, a RF power of 800 W, a dc bias of 200 V, a chamber pressure of 15 mTorr, and a substrate temperature of ${30^{\circ}C}$. From the X-ray photoelectron spectroscopy (XPS) analysis ， yttrium not only etched by chemical reactions with Cl radicals, but also assisted by Ar ion bombardments in $Ar/Cl_{2}$ plasma. In $CF_{4}/Cl_{2}$ plasma, yttrium are remained on the etched surface of $YMnO_{3}$ and formed of nonvolatile YFx compounds Manganese etched effectively by chemical reactions with Cl and F radicals. From the X-ray diffraction (XRD) analysis, the (0004) diffraction peak intensity of the $YMnO_{3}$ thin film etched in $Ar/Cl_{2}$ plasma shows lower value than that in $CF_{4}/Cl_{2}$ plasma. It is indicates that the crystallinty of $YMnO_{3}$ thin film is more easily damaged by the Ar ion bombardment than the changes of stoichiometry due to nonvolatile etch by-products.

• Journal of the Korean Vacuum Society
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• v.7 no.4
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• pp.390-396
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• 1998

Neutral stream was generated from Helicon plasma source and was applied to etch silicon for the purpose of preventing physical and electrical damages from the bombardment of charged particles with high translation energy. By installing a permanent magnet and applying positive bias beneath the substrate, the cusp-magnetic and electric fiddles were generated in order to remove the charged particles from the downstream plasma. As a result, the electron density and ion density in the vicinity of the substrate were reduced by 1/1000 and 1/10, respectively. The directional etching of silicon was observed and the etch rate was found to be very low to below 100 $\AA$/min at a pressure of $8.5{\times}10^{-4}$ Torr, when $Cl_2$ and 10% $SF_{sigma}$ etchant gases were used.

• Korean Journal of Materials Research
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• v.15 no.3
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• pp.161-165
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• 2005

We investigated selective dry etching of GaAs over AlGaAs and InGaP in high density planar inductively coupled $BCl_3/SF_6$ plasmas. The process parameters were ICP source power (0-500 W), RE chuck power (0-30W) and gas composition $(60-100\%\;BCl_3\;in\;BCl_3/SF_6)$. The process results were characterized in terms of etch rate, selectivities of GaAs over AlGaAs and InGaP, surface morphology, surface roughness and residues after etching. $BCl_3/SF_6$ selective etching of GaAs showed quite good results in this study. Selectivities of GaAs $(GaAs:AlGaAs\~36:1,\;GaAs:InGaP\~45:1)$ were superior at $18BCl_3/2SF_6$, 20 W RF chuck power, 300 W ICP source power and 7.5 mTorr. Addition of $(5-15\%)SF_6\;to\;BCl_3$ produced relatively high selectivities of GaAs over AlGaAs and InGaP during etching due to decrease of etch rates of AlGaAs and InGaP (boiling points of etch products: $AlF_3\~1300^{\circ}C,\;InF_3>1200^{\circ}C$ at atmosphere) at the condition. SEM and AFM data showed slightly sloped sidewall and somewhat rough surface$(RMS\~9nm)$. XPS study on the surface of processed GaAs proved a very clean surface after dry etching. It shows that planar inductively coupled $BCl_3/SF_6$ plasmas could be a good candidate for selective dry etching of GaAs over AlGaAs and InGaP.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.105-105
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• 2009

$ZrO_2$ is one of the most attractive high dielectric constant (high-k) materials. As integrated circuit device dimensions continue to be scaled down, high-k materials have been studied more to resolve the problems for replacing the EY31conventional $SiO_2$. $ZrO_2$ has many favorable properties as a high dielectric constant (k= 20~25), wide band gap (5~7 eV) as well as a close thermal expansion coefficient with Si that results in good thermal stability of the $ZrO_2/Si$ structure. In order to get fine-line patterns, plasma etching has been studied more in the fabrication of ultra large-scale integrated circuits. The relation between the etch characteristics of high-k dielectric materials and plasma properties is required to be studied more to match standard processing procedure with low damaged removal process. Due to the easy control of ion energy and flux, low ownership and simple structure of the inductively coupled plasma (ICP), we chose it for high-density plasma in our study. And the $BCl_3$ included in the gas due to the effective extraction of oxygen in the form of $BCl_xO_y$ compound In this study, the surface kinetic properties of $ZrO_2$ thin film was investigated in function of Ch addition to $BCl_3/Ar$ gas mixture ratio, RF power and DC-bias power based on substrate temperature. The figure 1 showed the etch rate of $ZrO_2$ thin film as function of gas mixing ratio of $Cl_2/BCl_3/Ar$ dependent on temperature. The chemical state of film was investigated using x-ray photoelectron spectroscopy (XPS). The characteristics of the plasma were estimated using optical emission spectroscopy (OES). Auger electron spectroscopy (AES) was used for elemental analysis of etched surface.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.145-145
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• 2008

High-k materials have been paid much more attention for their characteristics with high permittivity to reduce the leakage current through the scaled gate oxide. Among the high-k materials, $ZrO_2$ is one of the most attractive ones combing such favorable properties as a high dielectric constant (k= 20 ~ 25), wide band gap (5 ~ 7 eV) as well as a close thermal expansion coefficient with Si that results in good thermal stability of the $ZrO_2$/Si structure. During the etching process, plasma etching has been widely used to define fine-line patterns, selectively remove materials over topography, planarize surfaces, and trip photoresist. About the high-k materials etching, the relation between the etch characteristics of high-k dielectric materials and plasma properties is required to be studied more to match standard processing procedure with low damaged removal process. Among several etching techniques, we chose the inductively coupled plasma (ICP) for high-density plasma, easy control of ion energy and flux, low ownership and simple structure. And the $BCl_3$ was included in the gas due to the effective extraction of oxygen in the form of $BCl_xO_y$ compounds. During the etching process, the wafer surface temperature is an important parameter, until now, there is less study on temperature parameter. In this study, the etch mechanism of $ZrO_2$ thin film was investigated in function of $Cl_2$ addition to $BCl_3$/Ar gas mixture ratio, RF power and DC-bias power based on substrate temperature increased from $10^{\circ}C$ to $80^{\circ}C$. The variations of relative volume densities for the particles were measured with optical emission spectroscopy (OES). The surface imagination was measured by scanning emission spectroscope (SEM). The chemical state of film was investigated using energy dispersive X-ray (EDX).

• Journal of the Korean Vacuum Society
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• v.21 no.4
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• pp.199-204
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• 2012

$SF_6$ gas is widely used for dry etching process of semiconductor and display fabrication process. But $SF_6$ gas is considered for typical greenhouse gas for global warming. So it is necessary to research relating to $SF_6$ alternatives reducing greenhouse effect in semiconductor and display. $C_3F_6$ gas is one of the promising candidates for it. We studied about etch characteristics by performing Reactive Ion Etching process of dry etching and reduced gas element exhausted on etching process using absorbent Zeolite 5A. $Si_3N_4$ thin film was deposited to 500 nm with Plasma Enhanced Chemical Vapor Deposition and we performed Reactive Ion Etching process after patterning through photolithography process. It was observed that the etch rate and the etched surface of $Si_3N_4$ thin film with Scanning Electron Microscope pictures. And we measured and compared the exhausted gas before and after the absorbent using Gas Chromatograph-Mass Spectrophotometry.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.72-72
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• 2015

메모리 반도체 세계 시장 점유율 1위 뿐만 아니라 국내 전체 산업 가운데 가장 중추적인 역할을 하는 반도체 산업의 지속적인 성장과 국가 경제의 발전을 위해서 소자 업체 뿐만 아니라 장비, 소재, 부품 산업의 동반 성장은 반드시 필요하다. 그 중에서 특히 소재, 부품 산업을 발전시키는 것이 국산 반도체 장비의 시장 점유율이 낮은 현 시점에서 가장 필요한 선택이다. 반도체 소재, 부품 산업의 발전을 위해서 제일 먼저 해야할 일은 영세한 국내 반도체 소재, 부품 산업을 활성화 시키는 것이며, 지속 적인 연구 개발, 성능 평가 방안 확보, 수요 업체와의 연계 방안 확보 등이 주요 현안이다. 반도체 소자 업체, 장비 업체에서 원하는 소재 및 부품의 성능을 만족하는 제품을 만들기 위해서는 우선 소재 및 부품의 기본 특성을 만족하는지에 대한 평가가 필요하고, 더 나아가서는 디바이스의 특성을 만족시켜줄 수 있는 한 단계 상향된 수요자의 요구 조건을 만족 시켜줄 수 있어야 한다. 본 연구에서는 그 중 특히 중요한 요소인 성능 평가에 대해서 논하고자 한다. 우선 반도체 공정용 소재에 대해서 살펴 보면 대표적인 반도체 소재로 증착용 Precursor, Photo Resistor, Sputter Target 등이 있다, 평가 방법으로는 ALD용 Precursor의 경우 대기 노출시 폭발, 화염 발생 등의 위험 요소를 안고 있어 특별한 주의가 요구 된다. PR이나 Sputter Target은 상대적으로 위험성은 적으며, 다양한 성능 평가 들이 가능하다. 다음으로 부품 평가에 대해서 살펴 보자. 본 원에서 가장 많이 진행된 부품 평가는 개발된 Pump의 성능 평가이다. 개발된 Pump는 1차적으로 KRISS 진공센터 에서 기본 Pumping 능력 평가를 실시하고, 다음으로 공정 평가를 실시한다. Pump마다 특성이 달라서 각 펌프의 성능 평가에 적합한 공정과 장비를 우선 선정하고 그에 합당한 공정을 진행하여 평가를 실시한다. 고 진공용인 Cryo Pump는 순수한 물질의 증착이 중요한 Metal Sputter 공정 장비에 장착하여 공정용 Gas를 흘리면서 Pump의 구동에 따른 성능 평가를 하고, 다음으로 실제로 Metal Sputter를 실시해서 Wafer에 증착된 물질의 특성을 확인한다. 다음으로 Turbo Pump의 경우 Etch 장비에 장착하여 Etch Uniformity, Etch Rate, By-product 배출 정도에 대해서 평가를 한다. Dry Pump는 비교적 공정 압력이 낮은 PECVD 공정 장비에서 평가를 진행 한다. 마지막으로 공정 진단, 챔버 상태 진단 등을 할 수 있는 별도의 부품 또는 장치로 PBMS, PCDS, OES 등의 평가에 대해서 논한다. 본 장치들은 실제 반도체 공정 장비와 환경에서 평가가 되어야지만 최종 사용자 입장에서 신뢰를 가지고 결과에 대해서 접근할 수 있다. 위에 논의된 장치들은 현재 공정 장비에 부착되어서 판매 되고 있는 것이 아니라 수요가 많지 않으나, 자체 성능 개선과 적합한 평가를 통해서 장치의 성능이 인정되면 300 mm 이상 Wafer 공정에서 반드시 필요한 실시가 공정 진단을 위해서 폭발적인 수요를 창출할 수 있으리라 본다.

• Korean Journal of Materials Research
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• v.19 no.2
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• pp.68-72
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• 2009

This study investigated dry etching of acrylic in capacitively coupled $SF_6$, $SF_6/O_2$ and $SF_6/CH_4$ plasma under a low vacuum pressure. The process pressure was 100 mTorr and the total gas flow rate was fixed at 10 sccm. The process variables were the RIE chuck power and the plasma gas composition. The RIE chuck power varied in the range of $25{\sim}150\;W$. $SF_6/O_2$ plasma produced higher etch rates of acrylic than pure $SF_6$ and $O_2$ at a fixed total flow rate. 5 sccm $SF_6$/5 sccm $O_2$ provided $0.11{\mu}m$/min and $1.16{\mu}m$/min at 25W and 150W RIE of chuck power, respectively. The results were nearly 2.9 times higher compared to those at pure $SF_6$ plasma etching. Additionally, mixed plasma of $SF_6/CH_4$ reduced the etch rate of acrylic. 5 sccm $SF_6$/5 sccm $CH_4$ plasma resulted in $0.02{\mu}m$/min and $0.07{\mu}m$/min at 25W and 150W RIE of chuck power. The etch selectivity of acrylic to photoresist was higher in $SF_6/O_2$ plasma than in pure $SF_6$ or $SF_6/CH_4$ plasma. The maximum RMS roughness (7.6 nm) of an etched acrylic surface was found to be 50% $O_2$ in $SF_6/O_2$ plasma. Besides the process regime, the RMS roughness of acrylic was approximately $3{\sim}4\;nm$ at different percentages of $O_2$ with a chuck power of 100W RIE in $SF_6/O_2$ plasma etching.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.169-169
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• 2008

To keep pace with scaling trends of CMOS technologies, high-k metal oxides are to be introduced. Due to their high permittivity, high-k materials can achieve the required capacitance with stacks of higher physical thickness to reduce the leakage current through the scaled gate oxide, which make it become much more promising materials to instead of $SiO_2$. As further studying on high-k, an understanding of the relation between the etch characteristics of high-k dielectric materials and plasma properties is required for the low damaged removal process to match standard processing procedure. There are some reports on the dry etching of different high-k materials in ICP and ECR plasma with various plasma parameters, such as different gas combinations ($Cl_2$, $Cl_2/BCl_3$, $Cl_2$/Ar, $SF_6$/Ar, and $CH_4/H_2$/Ar etc). Understanding of the complex behavior of particles at surfaces requires detailed knowledge of both macroscopic and microscopic processes that take place; also certain processes depend critically on temperature and gas pressure. The choice of $BCl_3$ as the chemically active gas results from the fact that it is widely used for the etching o the materials covered by the native oxides due to the effective extraction of oxygen in the form of $BCl_xO_y$ compounds. In this study, the surface reactions and the etch rate of $Al_2O_3$ films in $BCl_3/Cl_2$/Ar plasma were investigated in an inductively coupled plasma(ICP) reactor in terms of the gas mixing ratio, RF power, DC bias and chamber pressure. The variations of relative volume densities for the particles were measured with optical emission spectroscopy (OES). The surface imagination was measured by AFM and SEM. The chemical states of film was investigated using X-ray photoelectron spectroscopy (XPS), which confirmed the existence of nonvolatile etch byproducts.