• 조명전기설비학회논문지
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• 제19권4호
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• pp.1-8
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• 2005

본 연구에서는 2차원적 유체 모델을 통하여 보다 실질적인 플라즈마를 이해하고자 하였으며, 기하학적인 방전전극 구조를 반영하도록 전극단에서 챔버 외벽의 거리를 변화시키면서 플라즈마의 특성을 정량적으로 비교 분석하고자 하였다. 방전 챔버의 구조로서, 전극의 반경과 방전 챔버의 높이는 일정하게 유지하면서 방전 챔버의 넓이를 변화시킴에 따라 형성되는 플라즈마의 특성을 분석하였다. 그 결과, 전극단과 챔버 외벽의 거리가 짧을수록 그 영역에서 전계가 강하게 형성되어, 외벽을 향하는 각 입자들의 움직임도 매우 활발하다는 것을 알 수 있었다. 또한, 전각단과 외벽과의 거리가 짧을수록 전극 면상에서 형성되는 입자들의 수밀도와 유속의 변화가 일정하게 형성되는 것을 알 수 있었다. 이러한 결과는 웨이퍼의 대구경화에 따른 플라즈마의 균일성을 고려할 경우에 매우 효과적일 것으로 고려되어 진다.

• 한국융합학회논문지
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• 제11권10호
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• pp.1-7
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• 2020

뉴로모픽 소자 초기 단계인 저항 변화형 메모리 소자의 제작 공정으로, 진공 공정의 연속성을 유지하였고, 고집적, 고신뢰성을 보장하는 뉴로모픽 컴퓨팅을 위한 저항 변화 메모리 소자 제작 및 공정 기술에 적합한 플라즈마 모듈을 적용하였다. 플라즈마 모듈을 적용한 저항메모리(ReRAM) 소자의 제작과 연구는 ReRAM 소자 기반의 TiO₂/TiOx 산화물박막의 제작방법과 소재의 변화를 통한 다양한 실험을 통하여 완성되었다. XRD를 이용하여 rutile결정을 측정하였고, 반도체 파라미터 측정기로 저항 메모리의 HRS : LRS 비율이 2.99 × 10³ 이상이고, 구동 전압 측정이 0.3 V이하에서 구동이 가능한 저항 변화형 메모리 소자의 제작을 확인 하였다. 산소 플라즈마 모듈을 적용한 뉴로모픽 저항메모리 제작과 TiOx 박막을 증착하여 성능을 확인하였다.

• 센서학회지
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• 제23권5호
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• pp.337-341
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• 2014

For various additives doped-$VO_2$ critical temperature sensors using the nature of semiconductor to metal transition, the crystallinity, microstructure, and temperature vs. resistance characteristics were systematically investigated. As a starting material of $VO_2$ sensor, vanadium pentoxide ($V_2O_5$) powders were used, and CaO, SrO, $Bi_2O_3$, $TiO_2$, and PbO dopants were used, respectively. The $V_2O_5$ powders with dopants were mixed with a vehicle to form paste. This paste was silk screen-printed on $Al_2O_3$ substrates and then $V_2O_5$-based thick films were heat-treated at $500^{\circ}C$ for 2 hours in $N_2$ gas atmosphere for the reduction to $VO_2$. From X-ray diffraction analysis, $VO_2$ phases for pure $VO_2$, and CaO and SrO-doped $VO_2$ thick films were confirmed and their grain sizes were 0.57 to $0.59{\mu}m$. The on/off resistance ratio of the $VO_2$ sensor in phase transition temperature range was $5.3{\times}10^3$ and that of the 0.5 wt.% CaO-doped $VO_2$ sensor was $5.46{\times}10^3$. The presented critical temperature sensors could be commercialized for fire-protection and control systems.

• 한국진공학회지
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• 제18권6호
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• pp.468-473
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• 2009

Chemical beam epitaxy 성장법으로 InP/InGaAs 다층구조의 선택적 영역 에피성장 (selective area epitaxy)을 하였다. <011> 방향에 평행한 직선패턴에서는 선폭이 작아지고, <01-1> 방향에 평행한 직선패턴에서는 선폭이 증가하는 현상이 나타났는데 이는 InGaAs의 <311>A와 B면이 <01-1> 방향에 평행한 직선패턴에서 성장되었기 때문으로 설명되었다. 성장속도가 $1\;{\mu}m/h$인 조건에서 5족 가스의 압력이 감소할수록 (100) 면 위에서 평평한 에피층이 성장되었는데 이는 5족 가스의 과포화현상에 의한 3족 원소의 표면이동으로 설명하였다.

• 한국산업융합학회 논문집
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• 제10권4호
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• pp.213-219
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• 2007

Glass-to-metal contact should be prevented in the design of any structural glass component. Because glass is extremely brittle and will fracture readily if even a small point load is applied. If the assembly includes a glass component supported by metallic structure, designers should provide a pliable interface of some kind between the two parts. But there happens high demand of glass-to metal contact in semiconductor industries due to adoption of dry cleaning process as one of the good solution to reduce running cost - carry out equipments cleaning with high corrosive and etching gas such as CF4 with keeping process temperature as the same as high service temperature. Therefore the quartz glass have to be received compression by direct contact with metal as the form of weight itself and vacuum pressure and fatigue by vibrations caused by process during the process. In this paper investigation will be carried out on fracture behavior of quartz glass contacted with metal directly under local load and fatigue given by process vibration with apparatus which can give $lox{\backslash}cal$ load and vibration through PZT ceramics to give guideline to prevent unintended fracture of quartz glass.

• 기술사
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• 제24권6호
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• pp.106-112
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• 1991

Electronics has different meanings to different people and in different countries. Hence, let me difine the term in the sense that it is used here. Electronics in the science and the technology of the passage of charged particles in a gas, in a vacumn, or in a semiconductor. The beginning of electronics came in 1895 when H. A. Lorentz postulated the existence of discrete charges called electrons. Two years later J.J. Thompson found these electrons experimentally. In the same year (1897) Braun built what was probaly the first electron tube, essentially a primitive cathode-ray tube. It was not until the start of the 20th century that electronics began to take technological shape. In 1904 Fleming invented the diode which he called a valve. This era begins with the invention of the transistor about 30 years ago. The history of this invention is interesting. M.J. Kelly, director of research(and later president of Bell Laboratories), had the foresight to realize that the telephone system needed electronic switching and better amplifiers. Vacuum tubes were not very reliable, principally because they generated a great deal of heat even when they were not being used, and, particularly, because filaments burned out and the tubes had to be replaced. In 1945 a solid-state physics group wa formed. The foregoing completes the history of electronics and electronic industries up to 1978. There is already a start toward a merging of the computer and the communication industries which might be called information manipulation. This includes storage of information, sorting, computation, information retrieval, and transmission of data. This combination of the computer and the communication fields will penetrate many disciplines. Applications will be made in the fields of law, medicine, biological sciences, engineering, library services publishing banking, reservation systems, management control, education, and defense.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.613-617
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• 2001

The test items like as endurance, air leakage and oil endurance test is requested for reliability evaluation about O-ring which is a kind of core machinery accessories of semi-conduct manufacturing equipment. For verification of these, we design and manufactured a test system for endurance, air leakage and oil endurance of O-ring for semi-conduct manufacturing equipment, and also performed the test for two kinds of O-ring, as it were Viton and Kalretz. The characteristics of this test equipment consist in realization of the test conditions of semi-conduct manufacturing equipment and satisfying the test method. The test conditions are cut gas, vacuum grade, temperature and revolution numbers in the endurance test system, vacuum grade and temperature in the air leakage test system, temperature and time in the oil endurance test system. The separating test results for wearing which is an oil endurance test item, the wearing index of domestic produced Viton O-ring is higher than foreign product by 2%, wearing rate of Kalretz O-ring better than Viton O-ring by 17%, and particles existed in various place. The test result of air leakage which is measured through the RGA sensor used Helium, the vacuum grade was $10^-3$Torr. And the test result of oil endurance, the volume change rate was 7~15%. Hereafter, we intend to analysis the reliability test evaluation and to utilize for domestic manufacturing companies by establishing data base and developing reliability softwares.

• 한국전기전자재료학회논문지
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• 제11권3호
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• pp.195-202
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• 1998

The LPCVD system of batch type for the massproduction of semiconductor fabrication has a problem of phosphorous concentration uniformity in the boat. In this paper we study an improvement of the uniformity for phosphorous concentration and sheet resistance. These property was improved by using the nitrogen process and modified long nozzle for gas injection tube in the doped polysilicon deposition system. The phosphorous concentration and its uniformity for polysilicon film are measured by XRF(X-ray Fluorescence) for the conventional process condition and nitrogen process. In conventional process condition, the phosphorous concentration, it uniformity and sheet resistance for polysilicon film are in the range of 3.8~5.4$\times$10\ulcorner atoms/㎤, 17.3% and 59~$\Omega$/ , respectively. For the case of nitrogen process the corresponding measurements exhibited between 4.3~5.3$\times$10\ulcorner atoms/㎤, 10.6% and 58~81$\Omega$/ . We find that in the nitrogen process the uniformity of phosphorous concentration improved compared with conventional process condition, however, the sheet resistance in the up zone of the boat increased about 12 $\Omega$/ . In modified long nozzle, the phosphorous concentration, its uniformity and sheet resistance for polysilicon films are in the range of 4.5~5.1$\times$10\ulcorner atoms/㎤, 5.3% and 60~65$\Omega$/ respectively. Annealing after $N_2$process gives the increment of grain size and the decrement of roughness. Modification of nozzle gives the increment of injection amount of PH$_3$. Both of these suggestion result in the stable phosphorous concentration and sheet resistance. The results obtained in this study are also applicable to process control of batch type system for memory device fabrication.

• 한국전기전자재료학회논문지
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• 제14권2호
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• pp.93-98
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• 2001

YMnO$_3$ films are excellent gate dielectric materials of ferroelectric random access memories (FRAMs) with MFSFET (metal -ferroelectric-semiconductor field effect transistor) structure because YMnO$_3$ films can be deposited directly on Si substrate and have a relatively low permittivity. Although the patterning of YMnO$_3$ thin films is the requisite for the fabrication of FRAMs, the etch mechanism of YMnO$_3$ thin films has not been reported. In this study, YMnO$_3$thin films were etched with Cl$_2$/Ar gas chemistries in inductively coupled plasma (ICP). The maximum etch rate of YMnO$_3$ film is 285$\AA$/min under Cl$_2$/(Cl$_2$+Ar) of 1.0, RF power of 600 W, dc-bias voltage of -200V, chamber pressure of 15 mTorr and substrate temperature of $25^{\circ}C$. The selectivities of YMnO$_3$ over CeO$_2$ and $Y_2$O$_3$ are 2.85, 1.72, respectively. The selectivities of YMnO$_3$ over PR and Pt are quite low. Chemical reaction in surface of the etched YMnO$_3$ thin films was investigated with X-ray photoelectron spectroscopy (XPS) surface of the selected YMnO$_3$ thin films was investigated with X-ray photoelectron spectroscopy(XPS) and secondary ion mass spectrometry (SIMS). The etch profile was also investigated by scaning electron microscopy(SEM)

• 공업화학
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• 제20권1호
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• pp.99-103
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• 2009

반도체 소자의 실리콘 게이트 전극 식각공정은 산화막에 대한 높은 식각 선택비와 정확한 식각형상 제어 등의 공정요구 조건을 충족시키기 위해 고밀도 플라즈마 식각공정을 사용하나 식각 후 notching이 발생되는 문제점을 보이고 있다. 특이하게 도핑 되지 않은 비정질 실리콘을 게이트 전극 물질로 사용한 경우 발생된 notching의 위치가 가장 외곽에 위치한 게이트 전극선의 바깥쪽에서 주로 발생되는 것이 관찰 되었다. 본 연구에서는 $Cl_2/HBr/O_2$의 식각기체 구성으로 notching 발생이 식각변수들에 따라 받는 경향성을 파악하고, 식각장치 내에서 실리콘 기판에 도달하는 식각 이온들의 진행경로를 분석하였다. 주 원인은 플라즈마 내의 식각 활성종 이온들이 대전효과에 의하여 궤적의 왜곡이 일어나 notching 현상이 발생되는 것으로 파악되었다. 이 결과를 바탕으로 도핑 되지 않은 비정질 실리콘 게이트 식각에서 발생하는 notching의 형성기구를 정성적으로 설명하였다.