Wang Yin-Yue

Electrical Properties of La-Doped Al2O3 Films on Si(100) Substrates as a High-Dielectric-Constant Gate Material

Amorphous La-doped Al2O3 (La: Al2O3) thin films are deposited on n-type (100) Si substrates by rf magnetron co-sputtering. The composition of the deposited films is measured by energy dispersive x-ray spectroscopy. Capacitance–voltage measurement shows that the dielectric constant k of La-doped Al2O3 films ranges from 8.5 to 11.6 with the increasing La content, and the highest k value of 11.6 is obtained for the 20.14% La content film. In the structure of the Al/La:Al2O3/Si metal oxide semiconductor, the dominant conduction stems from the space-charge-limited current at different temperatures. In addition, the wavelength dependence of the transmittance is studied by ultraviolet spectroscopy and the band gap of all the deposited films is above 5.5 eV. The results demonstrate that La-doped Al2O3 can meet the requirement of next-generation gate materials.

Preparation of transparent conductive ZnO：Tb films and their photoluminescence properties

Tb-doped Zinc oxide (ZnO:Tb) films were prepared by RF reactive magnetron sputtering of a Zn target with some Tb-chips attached. The results show that the appropriate Tb ions incorporated into ZnO films can improve the structural and electrical properties of ZnO films. Photoluminescence (PL) measurements show that the characteristic emission lines correspond to the intra-4fn-shell transitions in Tb3+ ions at room temperature. Under the optimal conditions, the ZnO:Tb films were prepared with the lowest resistivity (ρ) of 9.34 × 10−4Ωcm, transmittance over 80% at the visible region and the strong blue emission.

Adsorbate and light-induced effects on the conductivity in GD a-SixC1 - x: H

Abstract The effects of water adsorbate on dc dark conductance of GD a-Si x C 1 - x : H films are presented in this paper. The experiments have shown that adsorbed H 2 O acts as electron donor and increases the intrinsic or n-type sample conductance, while it decreases the conductance for p-type samples. It has been found that GD a-Si x C 1 - x : H films show weak Staebler-Wronski effects

Photonic Band Gap Properties of Three-Dimensional SiO2 Photonic Crystals

Three-dimensional SiO2 photonic crystals (PhCs) are fabricated on quartz substrates by the vertical deposition method. Scanning electron microscopy measurement reveals that the samples exhibit an ordered close-packed arrangement of SiO2 spheres. It is found that the position of the [111] photonic band gap (PBG) shifts to a long wavelength (red shift) with increasing sphere size. Gap broadening effects are observed due to the presence of defects in the samples. Moreover, the optical properties of the PBG are very sensitive to the annealing temperature. Our results indicate that the optical properties of the PBG can be easily tuned in the visible region by appropriate experimental parameters, which will be useful for practical applications of PhC optical devices.

Au/Ti/p-Diamond Ohmic Contacts Prepared by Radio-Frequency Sputtering

The as-deposited Au/Ti/p-diamond contacts prepared by rf sputtering are ohmic. The ohmic characteristics of the contacts are improved after annealing. As for the as-deposited and annealed contacts, the specific contact resistivities of 2.886 ? 10-3 and 2.040 ? 10-4 ??cm2 are obtained, respectively. The x-ray photoelectron spectroscopy analysis indicates that the titanium carbide formation occurs at the interface between titanium and the diamond substrate in the as-deposited state, and no TiO2 is observed.

Influence of HF catalyst on the microstructure properties of ultra low-k thin films prepared by sol-gel method

This paper reports that by using the hydrofluoric acid (HF) as the acid catalyst, F doped nanoporous low-k SiO2 thin films have been prepared by means of sol-gel method. The characterization of atomic force microscopy and Fourier transform infrared spectroscopy demonstrates that the HF catalyzed films are more hydrophobic. The N2 adsorption/desorption experiments show that the suited introduction of HF increases the porosity and decreases the pore size distribution (about 10 nm) in the films. The above results indicate that the hydrofluoric acid is the more suitable acid catalyst than the hydrochloric one for preparing nanoporous ultra low-k SiO2 thin films.

Light‐induced effect in a‐SixC1−x: H films

The paper presents the light‐induced effect of n‐ and p‐type GD a‐SixC1−x: H films by the use of MOSFET structure and coplanar contacts. It was found that, after prolonged light illumination, the gap state density increases and the photoconductance shows a slight decrease. The dark conductance of B state is related to EA (the A state activation energy).