Man-ho Cho
Yonsei University · 材料科学
研究室紹介
Professor Man-ho Cho's research lab specializes in the development and characterization of advanced oxide and nitride semiconductor thin films for next-generation electronic and optoelectronic applications. The lab focuses on interface engineering, atomic-scale doping, and resistive switching mechanisms in high-κ dielectrics and rare-earth doped oxides, with an emphasis on controlling electronic and optical properties through precise deposition and annealing techniques. Key research directions include the integration of functional oxide layers (e.g., HfO₂, TiO₂, La₂O₃, Al₂O₃) in semiconductor devices, defect control in ultrathin films, and the exploration of luminescent materials for solid-state lighting and memory applications.
Research Overview
Research Output Trend
Figures are computed from collected data and may differ slightly.
Selected Papers
15The effects of plasma nitridation conditions, including substrate temperature (room temperature or high temperature) and plasma source gas (N_2 or NH_3), on the energy band characteristics and the chemical states of ultrathin SiON films was studied by using reflection electron energy loss spectroscopy (REELS) and X-ray photoelectron spectroscopy (XPS). The depth profile of nitrogen incorporated in the SiON films as a function of the above conditions was examined using mediumenergy ion scattering
The effects of different irradiation doses of hydrogen ions on TiO<SUB>2-x</SUB> oxide semiconductor films were investigated.쟕he total doses were controlled between ~10<SUP>14</SUP> and ~10<SUP>15</SUP> atom/cm<SUP>2</SUP> at acceleration energy of 110 keV.?Hall mobility was manipulated with changing irradiation dose, while carrier concentration did not.쟕he amorphous crystal structure was consistently maintained upon irradiation. The electronic structures of molecular orbitals in the conduction
The interfacial reactions and electrical characteristics of stack structures of La2O3 and Al2O3 were investigated as a function of the annealing temperature. In the case of Al2O3/La2O3/Si (ALO structure), the La2O3 in contact with the Si substrate was readily transformed into La-silicate by the diffusion of Si atoms, while in the case of La2O3/Al2O3/Si (LAO structure), interfacial reactions between the Al2O3 layer and the Si substrate were suppressed. After an annealing treatment at 700 C, the A
In-Te films were deposited by ion beam sputtering deposition (IBSD) using In and Te targets. The crystallization characteristics of the resulting films were investigated by 4-point Rs measurement, x-ray diffraction (XRD),transmission electron microscopy (TEM), and the Hall-effect measurement system. As the amount of In was increased in In-Te, the crystallization temperature increased. X-ray data for the crystalline structure show that phase separation to In2Te3 and InTe occurred in InTe and In3T
Eu^3+-doped epitaxial Gd_2O_3 (111) films with well-ordered crystalline structures were grown on oxidized Si (111) using the physical vapor deposition method. The mole fraction (x) of Eu^3+ in Gd_(2-x)O_3:Eu^3+_x ranged from 0.02 to 0.22. The photoluminescence characteristics, measured at an excitationwavelength of 254 nm,showed that even at the very low Eu^3+ concentration, x = 0.18, the 5^D_0 → 7^F_2 transition occurred at the maximum612-nm emission. Based on the critical distance calculated u
We describe a new resistivity image reconstruction algorithm called J-substitution algorithm. It utilizes internal current density data measured by MRI technique with current injection. Computer simulations show that Magnetic Resonance Electrical Impedance Tomography (MREIT) system using J-substitution algorithm can produce high-resolution static resistivity images of a subject.
We have fabricated TiN/(HfO2)/TiO2/Pt/Ti stacks on SiO2/Si substrates and investigated the characteristics of the bipolar resistive switching of those stacks. Compared to the single TiO2 structure, more stable bipolar switching in the current-voltage curve was accomplished in the HfO2/TiO2 structure. We obtained a smaller range of SET variation, a larger sensing margin, and higher resistance values of the high-resistance state with an additional HfO2 layer. Especially, in the case of the HfO2/Ti
The catalyst-free growth of ZnO nanostructures on Si and SiO2/Si substrates as a function of substrate temperature was carried out using a thermal evaporation method. We observed that the shapes and the morphologies of the ZnO nanostructures could be controlled by using the substrate temperature and the presence of an oxide layer on the surface of the substrate. The shape of the ZnO nanostructure was changed from an embossed nanocantilever to a nanowire as the growth temperature was decreased fr
Amorphous silicon oxide nanowires (a-SiONWs) were prepared by heating a silicon substrate in the absence of any silicon source. To investigate the mechanism of this growth, we experimented with a variety of growth conditions, including the condition of the substrate and the growth ambient. The distribution of the density of a-SiONWs increased when titanium was present during the operation process. The results as a function of the temperature indicate that the growth mechanism for the high-temper
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
In this study, we evaluated the change of electronic structure during redox process in cerium-doped ZrO2 grown by sol gel method. By sol-gel method, we could obtain cerium-doped ZrO2 in high oxygen partial pressure and low temperature. After post annealing process in nitrogen ambient, the film is deoxidized. We used spectroscopic and theoretical methods to analysis change of electronic structure. X-ray absorption spectroscopy (XAS) for O K1-edge and Density Functional Theory (DFT) calculation us