극(劇)의 표현(表現) 대상(對象)으로서의 악(惡) -세익스피어 비극(悲劇)의 경우-

이연환 전남대학교 인문학연구소 1983 용봉인문논총 Vol.13 No.-

다공성에 따른 다공질 실리콘의 전기 광학적 특성 연구

이연환,권영해 東國大學校 1997 東國論叢 Vol.36 No.-

We present the existence of deep level defects in the band gap of porous silicon by the photoinduced current transient spectroscopy (PICTS) technique combined with the results of thermovoltage and conductivity measurements. The defects are found to exhibit deep donor levels in the upper part of the band gap. It is found that the thermal emission and ionization energies of the defect increase in the ranges from 0.3 eV to 0.86 eV below the conduction band edge as the porosity increases indicating that the defects play a role of a killer of luminescence. We suggest a configuration coordinate diagram to explain the observed defects uniquely.

GaAs(100) 기판 위에 성장된 InxGa1-xAs 변형층의 특성

이연환 동국대학교 경주대학 1996 東國論集 Vol.15 No.-

Photoluminescence (PL) and Raman spectroscopy measurements have been carried out to investigate the properties of InχGa1-χAs epitaxial layers grown on GaAs (100) substrates. In PL studies of InχGa1-χAs epitaxial layers, only one peak related near band was investigated for In composition x<O. 08 and in addition to that, another peak related donor-acceptor pair emission (DAP) was investigated for In composition x>0.08. As the In composition x increased, emission energy of DAP peak was decreased and FWHM of DAP peak was increased. According to the micro-Raman analysis, the InχGa1-χAs epitaxial layer had only one peak related GaAs-like LO phonon mode. It was shifted to the low frequency region as the In composition x increased.

Si 이온이 주입된 단결정 GaAs(100)에서의 sputtering 및 reflection에 대한 컴퓨터 계산

이연환 東國大學校 1993 東國論叢 Vol.32 No.-

A computer simulation based on the binary collision approximation has been performed to investigated the reflection coefficients and sputtering yields as function of incident angles, implantation doses, and implantation energies for Si-implanted GaAs(100) crystal. The results reveled a strong dependence on the incident angle of the Si ions. An enhanced reflection at 86° is found to occur at critical angle which can be described by the surface channeling theory. However, the reflection coefficient and the sputtering yield does not vary significantly as the implantation dose varied. In low energy region, reflection coefficient and spittering yield reveal a strong oscillatory structure. These results can be considered being due to the back scattering.

억압적 가족 문화와 동화적 폭력의 기원―마틴 맥도나의 『베개 유령』

이연환 21세기영어영문학회 2018 21세기영어영문학회 학술대회 Vol.2018 No.11

억압적 가족 문화와 동화적 폭력의 기원—마틴 맥도나의 <<베개 유령>>

이연환 21세기영어영문학회 2019 영어영문학21 Vol.32 No.1

Within the context of repressive family culture, this essay examines a train of fairytale violence that is submerged in Martin McDonagh’s problem play The Pillowman. This fairytale violence of the child abuse is represented by various layered storytellings via actor’s verbal performance in the play. It is true that the imbalance of power in society and family has been a chronic subject throughout human history. This principle of imbalanced power then has led to a never-ending burst of unilateral violence. Hence, McDonagh portrays drastically dark and wretched childhood story of the Katurian brothers in public. Because of the tacit secrecy or with memories of trauma, Katurian’s literary imagination is exaggerated with a disturbing Gothic fantasy in his fairytale writing. The staged violence unfolds old wounds and inveterate matters in human relations on the whole. So to speak, the lethal violence in this play asks for an urgent examination of the family and its relationship. And equally McDonagh indicates the gravity of destructiveness inherent in the politics of totalitarianism. He produces visually recursive representations of lifelike pain performance on the stage. With this, he forces us to consider issues of repression and violence within a family. At the conclusion, this essay puts meaning to review repressive family culture through tracing the fairytale violence mingled in The Pillowman.

Au-Si 나노점을 촉매로 성장한 Si 나노선의 구조 및 광학적 특성 연구

이연환,곽동욱,양우철,Lee, Y.H.,Kwak, D.W.,Yang, W.C.,Cho, H.Y. 한국진공학회 2008 Applied Science and Convergence Technology Vol.17 No.1

나노크기의 Au-Si을 촉매로 급속열화학기상증착(rapid thermal chemical vapor deposition)법을 이용하여 Si(111) 기판에 성장한 Si 나노선의 구조적인 형태 변화와 광학적 특성을 연구하였다. 기상-액상-고상(vapor-liquid-solid) 성장법에 의한 Si 나노선 형성 과정에서 액상 입자인 Au-Si 나노점은 나노선 성장온도에서 촉매로 사용되었다. 이 액상 나노점이 형성된 Si 기판에 1.0Torr 압력과 $500-600^{\circ}C$ 기판 온도 하에서 $SiH_4$와 $H_2$의 혼합가스를 공급하여 Si 나노선을 형성하였다. Si 나노선 성장 후 형태를 전계방출 주사전자현미경(Field Emission Scanning Electron Microscope)으로 관찰한 결과, 대부분의 나노선이 균일한 크기로 기판 표면에 수직하게 <111> 방향으로 정렬된 것을 확인하였다. 형성된 나노선의 크기는 평균 직경이 ${\sim}60nm$이고 평균 길이가 ${\sim}5um$임을 확인하였다. 또한 고 분해능 투과전자현미경(High Resolution-Transmission Electron Microscope) 관찰을 통해 Si 나노선은 약 3nm의 비정질 산화층으로 둘러 싸여 있는 Si 단결정임이 분석되었다. 그리고 마이크로 라만 분광(Micro-Raman Scattering)법을 통한 광학적 특성 분석 결과, Si의 광학 포논(Optical Phonon) 신호 위치가 Si 나노선 구조의 영향으로 낮은 에너지 쪽으로 이동하며, Si 포논 신호의 폭이 비대칭적으로 증가함을 확인하였다. we have demonstrated structural evolution and optical properties of Si-nanowires (NWs) synthesized on Si (111) substrates with nanoscale Au-Si islands by rapid thermal chemical vapor deposition (RTCVD). The Au-Si nano-islands (10-50nm in diameter) were employed as a liquid-droplet catalysis to grow Si-NWs via vapor-liquid-solid mechanism. The Si-NWs were grown by a mixture gas of SiH4 and H2 at a pressure of 1.0 Torr and temperatures of $500{\sim}600^{\circ}C$. Scanning electron microscopy measurements showed that the Si-NWs are uniformly sized and vertically well-aligned along <111> direction on Si (111) surfaces. The resulting NWs are ${\sim}60nm$ in average diameter and ${\sim}5um$ in average length. High resolution transmission microscopy measurements indicated that the NWs are single crystals covered with amorphous SiOx layers of ${\sim}3nm$ thickness. In addition, the optical properties of the NWs were investigated by micro-Raman spectroscopy. The downshift and asymmetric broadening of the Si main optical phonon peak were observed in Raman spectra of Si-NWs, which indicates a minute stress effects on Raman spectra due to a slight lattice distortion led by lattice expansion of Si-NW structures.

Si이 주입된 단결정 GaAs(100)에서의 Atomic displacement 및 Frenkel Pair형성에 관한 컴퓨터 계산

이연환 동국대학교 경주대학 1993 東國論集 Vol.12 No.-

A computer simulation based on the binary collision approximation has been performed to investigated the atomic displacements and the Frenkel pairs as function of incident algles, implantation doses, and implantation energies for Si-implanted GaAs (100) crystal. Vacancy yields and Frenkel pairs reveal a strong dependence on the incident angles of the Si ions. These values reveal the channeling phenomena at incident angle θ= 0˚, 18.4˚, 45˚, 71.5˚ corresponding to the channeling directions of GaAs<100>, <301>, <101>, and <103>. The Frenkel pairs produced in displacement cascades in Si ions reveal surface channeling phenomena at incident angle θ= 86˚. However vacancy yields and Frenkel pairs do not vary significantly as the implantation dose varied. In the region of low incident energy, the vacancies and Frenkel pairs of Si ions exhibit the results which can be considered being due to the back scattering of Si ions.

Silicon Rich Oxy­Nitride 비휘발성 메모리 구조에서의 계면상태 특성 연구

이연환,조훈영,김원식,서명원,오종수,오형택 한국물리학회 2006 새물리 Vol.53 No.6

The interface states and the activation energies in non-volatile MOS (metal-oxide-silicon) memory devices with SRON (silicon rich oxy-nitride) structures on Si substrates have been investigated using DLTS (deep level transient spectroscopy) and CV (capacitance-voltage) measurements. Especially, for the evaluation of the interface charge trapped at the interface, small pulse DLTS (SP-DLTS) measurements were used. From SP-DLTS, the D$_{it}$ (interface state density) is calculated to be 3.3 $\times$ 10$^{11}$ cm$^{-2}$eV$^{-1}$ in the as-prepared SRON sample, but is 4.8 $\times$ 10$^{10}$ cm$^{-2}$eV$^{-1}$in the sample annealed at 800$^\circ$C for 30 min. Also, D$_{it}$ was found to lower 2.0 $\times$ 10$^{10}$ cm$^{-2}$eV$^{-1}$ in the sample annealed at 1000 $^\circ$C for 60 min. This show that the interface states can affect the flat-band voltage shift, which affects the memory characteristics in SRON memory structures, and the that observed interface states might be related with silicon dangling bonds (SDB) or Si-H bonds. Also, the interface states in SRON structures can be controlled during thermal annealing processes. 실리콘 기판 위에 SRON (Silicon Rich Oxy-Nitride)구조로 제작한 비휘발성 금속 산화막 실리콘 (metal-oxide-silicon, MOS) 메모리 소자의 계면 상태 밀도, 포획 단면적, 그리고 활성화 에너지를 조사하기 위하여, DLTS (deep level transient spectroscopy) 와 CV (Capacitance-Voltage) 측정 방법을 이용하였다. 계면상태에서의 포획된 전하 (interface trap charge)를 조사하기에 위하여 SP-DLTS (small pulse DLTS) 측정 방법을 사용하여 비휘발성 메모리 구조의 계면 상태에서 포획된 전하 (interface trap charge)에 대하여 연구하였다. 비교 기준 시료인 SRON 구조 소자의 최대 D$_{it}$ (계면 상태 밀도)는 3.3 $\times$ 10$^{11}$ cm$^{-2}$eV$^{-1}$이었고, 대조군의 시료 중 800 $^\circ$C에서 30분 동안 열처리 한 소자의 계면 상태 밀도 D$_{it}$ 는 4.8 $\times$ 10$^{10}$ cm$^{-2}$ eV$^{-1}$이었으며, 1000 $^\circ$C에서 1시간 동안 열처리한 소자의 계면 상태 밀도 D$_{it}$ 는 2.0 $\times$ 10$^{10}$ cm$^{-2}$ eV$^{-1}$ 로 감소하는 것을 확인하였다. 이러한 결과로부터 본 연구에서는 계면 상태 밀도가 메모리 소자의 특성인 flat band voltage의 변화에 영향을 주는 것을 알 수 있었고, 이는 silicon dangling bond (SDB) 결함이나 Si-H bond에 의한 것으로 제안한다. 또한 열처리 과정을 통하여 MOS 소자의 계면 상태 밀도를 조절 할 수 있었다.

GaAs 에피층의 Ar+ 이온 sputtering ( Ar+ ion sputtering for GaAs epi layer )

이연환,강태원,홍치유,이정주,강희재,정관수 대한전자공학회 1986 대한전자공학회 학술대회 Vol.1986 No.1