산화된 실리콘 표면에 대한 방사선영향

姜甲中,金末文 嶺南大學校附設 基礎科學硏究所 1986 基礎科學硏究 Vol.6 No.-

The MOS capacitor is widely used in the study of radiation effect in SiO₂. The model assumes that hole-electron pairs are created in the SiO₂by the radiation and that some of the electrons thus created drift out of the SiO₂layer under the action of an applied potential (V?) across the oxide, while the corresponding holes become trapped. The C-V curves shift along the voltage axis to higher negative voltages, thus indicating that positive charge is being induced in the oxide as a result of exposure to ionizing radiation. Also, the induced positive oxide charge density increases with increasing radiation dose.

TSIC 방법으로 SiO₂층 내의 Ion에 따른 Two-Dim. Computer Simulation

손영호,한병국,김말문 嶺南大學校 基礎科學硏究所 1990 基礎科學硏究 Vol.10 No.-

Electrical Characteristics of current transport mechanism of mobile ions in MOS structure with SiO₂layer was two-dimensional computer simulation in general-order kinetics as well as first and second-order kinetics by TSIC method. We obtained the parameters (E,S) as a function of kinetics order(L), constant heating rate(B), initial concentration(no), half temperature(T?), and maximum temperature(T?) by the computer simulation. As the result, computer simulation revealed that kinetics order, form of TSIC curve and maximum temperature affect E and S largely.

DLTS에 의한 LPE GaAs 및 Al0.32Ga0.68As의 깊은준위 조사

金仁洙,崔玄泰,李哲旭,裵仁鎬,金末文 嶺南大學校 基礎科學硏究所 1993 基礎科學硏究 Vol.13 No.-

Deep levels in liquid phase epitaxy(LPE) GaAs and Al??Ga??As were investigated by deep level transient spectroscopy(DLTS) method. In LPE n-GaAs, The main electron trap observed was the T1(EL2) at Ec-0.82eV. For Al???Ga???As, two electron traps T2(Ec-0.32eV) and T3(Ec-0.82eV) were observed. The origins of EL2(Tl or T3) and DX center(T2) are As??-V?? complex and donor complex related impurity, respectively. After annealing at 795℃, the peak at low temperature decreased but peak at high temperature had broad shape and increased. The level observed at high temperature is EL2 family.

Raman 산란에 의한 InxGa1-xAs/GaAs 이종접합구조의 구조적 특성 연구

손정식,문영희,배인호,김말문 嶺南大學校 基礎科學硏究所 1996 基礎科學硏究 Vol.16 No.-

Using Raman Scattering, we have measured the resiual strain of InGaAs layers with 0≤ x < 0.33 grown on GaAs substrates. The samples under investigation were grown by molecular beam epitaxy system. The In composition was varied from x=0 to x<0.33 and the thickness of epilayer is fixed to 1㎛ which are more thick than critical layer thickness except bulk GaAs(x=0). Our result show that FWHM of GaAs-like LO phonon peak is not significant increase under 80% relaxation but TO/LO ratio is increase with In composition. We calculated relaxation ratio from Raman scattering measurements based on the theory of strain induced phonon shifts and which result compared with DCX measurements.

非晶質 SiC를 절연막으로 한 MIS 構造의 電氣的 特性

金末文,李進熙 嶺南大學校附設 基礎科學硏究所 1984 基礎科學硏究 Vol.4 No.-

The current-voltage characteristics in glow dscharge deposited amorphous SiC thin film on single crystal Si substrate exhibit space-charge limited current in the presence of exponentially distributed traps. Trap parameters are deduced from current-voltage data. Capacitance-voltage curve of A1-SiC-Si structure exhibit flat-band voltage shift 4.2V from ideal capacitance-voltage curve, and resulting fixed space charge densisity and interface state charge density are obtained, ??, ??, respectively.

MOS 구조에서 S₁O₂층의 Charge Trappiog

金末文,金在峯,南尙熙 嶺南大學校附設 基礎科學硏究所 1987 基礎科學硏究 Vol.7 No.-

In the process of avalanche injection of electrons into silicon dioxide, beside eloctron trapping in the bulk of the oxide, there are slow and fast inferface states generated. The slow state are donors and positive charged when empty. Togother with positive charge in the interface states, they compensated the negative bulk charge to give the turn-around effect. The final C-V carve is due to a complex sum of different charge components. As a function of avalanche fluence ?? , the flatband voltage shift did not increase monotonically. Instead, after a maximum voltage shift was reached, the flatband voltage decrease with further injection of electrons. The turn around effect is observed after ?? are injected into an oxide. The effect was explained by the generation of interface states.

MOS 소자의 移動性 陽이온들의 電氣的 特性

金末文,南尙熙 嶺南大學校附設 基礎科學硏究所 1985 基礎科學硏究 Vol.5 No.-

Thermally stimulated Ionic Current (TSIC) measurements have been used to study the kinetic behavior of mobil ions in Al-SiO₂-Si Structures formed by evaporation of Al electrodes onto thermally oxidized Si wafer. It is shown that three distinct peaks were observed in the temperature range 30~350℃. The first peak at about 100℃, and the second peak at about 200℃, and the third peak at about 350℃. The first peak is to the motion of ??, wheras the second peak results from the motion of ??, the third peak is to the motion of ??. It is shown that the ionic current is limited primarily by release of mobil ions from traps at the interface. This model is proposed which accurately predict the detrapping rate for an arbitary temperature-time profile and change of voltage. Its parameters are the initial distribution of ions among the trapping states, ??, and heating rate β, characterizing the attempt-to-escape frequency, and that trapped mobil ions release from trap. Activation energy, E canbe derived from analysis of a TSCI curve. Activatron energy is to the results of 0.52 for ??, and 0.81 for ??. The results is shallow trap for ??, and deep trap for ??. A value for β can be determined by performing experiment in the TSIC stages. Increase of peak current was caused by the increase of β. Changes of capacitance-voltage(C-V) characterics by Bias-Temperature(B-T) stresses have been measured for detecting mobil ions.

MBE(molecular beam epitaxy)로 성장된 GaAs/AlAs 초격자의 특성연구

김동렬,김말문 嶺南大學校 基礎科學硏究所 1996 基礎科學硏究 Vol.16 No.-

GaAs/AlAs superlattice was grown by molecular beam epitaxy with a thickness of 15 monolayers. We have performed photoluminescence measurement. Measurement were performed as a function of excitation laser power and temperature. The photoluminescence peak intensity as a function of excitation laser power is well described by a straight line on logarithmic plot, indicating that radiative recombination mechanism is excitonic-like transition. Finally, we have showed the temperature dependence of the peak energy of the HI-Cl transition. When lattice temperature was decreased, the peak energy first increased, following the temperature dependence of the bulk GaAs band gap, and deviated to the lower energy side by about 4 meV at 7.2K from extrapolated curve. The observed Stokes shift is in good agreement with previous results on multiple-quantum well sample of the high quality.

Cds-SiO₂-Si의 電氣的 特性

南尙熙,金末文 嶺南大學校附設 基礎科學硏究所 1981 基礎科學硏究 Vol.1 No.-

Introducting a passivating layer of SiO₂at the CdS-Si junction is found to improve the I-V characteristics of the heterodiodes. Studies indicate that the reverse-bias characteristics of these structures are determined primarily by the filling and unfilling of interface states at the Si-SiO₂ interface. This is substantiated by the temperature dependence of these characteristics. Reverse-bias C-V characteristics show abrupt junction like behavior, also controlled by the interface-state charge. Under forward-bias, tuneling through the oxide is responsible for conduction.

이온 주입된 실리콘에서 라만 특성 연구

김말문,이동건,문영희,한병국 嶺南大學校 基礎科學硏究所 1994 基礎科學硏究 Vol.14 No.-

Raman characterization measurements are performed in order to study the effects of the furnace annealing and rapid thermal annealing on arsenic implanted silicon wafers. The post-implanted period was followed by thermal isochronal annealing at various temperatures. Special attention has been given to the amorphous/crystal transition occurring at various annealing temperatures. The changes of the dimensions of the microcrystalline regions and the root mean square bond angle deviation of Si-Si bonds in amorphized regions are evaluated.