[en] Photoinduced characteristics of amorphous (a-) ZnSe thin films at 10 and 300 K have been investigated using real-time photoluminescence (PL) and X-ray diffraction. The structural phase of as-deposited film is evaluated to be predominantly amorphous with uniformly distributed nano-scale crystallites, and the optical energy gap and complex refractive index are approximately 2.928 eV and 3.04+i0.35 (at λ=325 nm), respectively. While the crystallite size is enlarged after illumination with HeCd laser at 300 K, a photodarkening effect without a change in crystallite size is observed in films illuminated at 10 K. That is, two types of temperature-dependent photoinduced changes are observed in a-ZnSe (i.e. amorphous-to-nanocrystalline transition at 300 K and amorphous-to-amorphous transition at 10 K). PL spectra of the photoinduced a-ZnSe measured at 10 K apparently show both the Stokes-shift and near band-edge broad peaks centered at ∼1.5 and ∼3.0 eV, respectively. In this work, we discuss a series of PL characteristics in a-ZnSe using a simple model based on valence-alternation pairs

[en] As a method to enhance the sensitivity (S) of an inorganic resist for focused-ion-beam (FIB), lithography, sub-0.1 μm patterning properties of a columnar structural α-Se₇₅Ge₂₅ resist have been investigated using 30 keV low-energy Ga⁺-FIB exposure and CF₄ reactive-ion etching (RIE). development. The Se₇₅Ge₂₅ thin films were 60 .deg. and 80 .deg. -obliquely deposited on Si substrate and parts of the films were annealed for several minutes at the glass transition temperature (T_g=∼220 .deg. C). Columnar structures with the angles of approximately 40 .deg. and 65 .deg. are observed in 60 .deg. and 80 .deg. -obliquely deposited films, respectively, and they disappear after annealing. Despite the disappearance of the columnar structures, a critical decrease in thickness is not observed. For the FIB exposures with a beam diameter of ∼0.1μm and around the threshold dose, the negative-type fine patterns with linewidth of about 0.06∼0.09 μm are fabricated successfully. Then, the imaging contrast (γ) is evaluated to be approximately 4.0 and the S to be ∼7.0x10¹⁴ ions/cm², which corresponds to about half that of normally (0 .deg. ) as -deposited resist

[en] Amorphous chalcogenide thin films have attracted much attention as a new advanced and replaceable material due to their electrical, optical and thermal properties. A programmable metallization cell (PMC) uses chalcogenide materials containing dissolved metal ions. A PMC is based on the electrochemical growth and removal of nanoscale metallic pathways in chalcogenide thin films of solid electrolytes. Samples of bulk AsGeSeS glasses have been prepared by melt quenching. A solid electrolyte material device without an access transistor has been successfully fabricated with a chalcogenide resistor with a Ag layer. We investigated resistance change characteristics with temperature and electric field direction on Ag/As₄₀Ge₁₀Se₁₅S₃₅ chalcogenide thin-film structure for PMC. Also, other evidence was confirmed, such as Auger electron spectroscopy for knowing the doping distance of metallic ions within the chalcogenide thin film. As the heat changes, each sample showed lower or higher resistance. The estimated resistance ratio was approximately 3000 times.

[en] We have demonstrated new functionalities of Ag-doped chalcogenide glasses based on their capabilities as solid electrolytes. The influence of silver on the properties of the newly formed materials is regarded in terms of diffusion kinetics, and Ag saturation is related to the composition of the hosting material. Silver saturated in chalcogenide glass has been used in the formation of solid electrolyte, which is the active medium in the programmable metallization cell (PMC) device. In this paper, we investigated the optical properties of Ag-doped chalcogenide thin film by He-Ne laser beam exposure, which is concerned with the Ag-doping effect of PMCs before or after annealing. Chalcogenide bulk glass was fabricated by a conventional melt quenching technique. Amorphous chalcogenide and Ag thin films were prepared by e-beam evaporation at a deposition rate of about 4 A s^-1. As a result of resistance change with laser beam exposure, the resistance abruptly dropped from the initial value of 1.4 MΩ to the saturated value of ∼400 Ω.

[en] An effective resistive-switching effect has been observed in silicon nitride (Si₃N₄) dielectrics in Ag/Si₃N₄/Al memory cells. The ratio of the low resistance to high resistance state was larger than 10⁷ at ±1.2 V for a 10 nm thick Si₃N₄ layer. This switching behavior is attributed to a change in the conductivity of the Si₃N₄ dielectrics, depending on whether nitride-related traps are filled with electrons under positive biases or unfilled under negative biases. This assertion is experimentally confirmed from the relationship between the amount of charges trapped in the Si₃N₄ layer and the corresponding changes in its resistance with respect to bias voltages. In addition, the formation or dissolution of the conductive path is confirmed by conductive atomic force microscopy current images