In the last decade, the III-N compounds have attracted much interest because of their applications in blue, violet and ultraviolet optoelectronics. Most of the devices and research use sapphire as a substrate for epitaxy of nitrides. However, these epi-structures contain a very high dislocation density induced by the 16% lattice mismatch between GaN and sapphire. In our laboratory, we grow single ...
A graphite capping layer has been evaluated to protect the surface of patterned and selectively implanted 4H–SiC epitaxial wafers during post-implantation annealing. AZ-5214E photoresist was spun and baked in vacuum at temperatures ranging from 750 to 850 °C to form a continuous coating on both planar and mesa-etched SiC surfaces with features up to 2 µm in height. Complete conversion of the hydro...
PAM-XIAMEN grows high quality Gallium Antimonide (GaSb) single crystal ingots. We also round, saw cut, lap and polish GaSb wafers and can supply an epi-ready surface quality. GaSb crystal is a compound formed by 6N pure Ga and Sb element and is grown by Liquid Encapsulated Czochralski ( LEC ) method with EPD < 1000 cm -3 . GaSb crystal has high uniformity of electrical parameters and low defect...
In this paper we review the developments of producing non-polar (i.e. m-plane and a-plane) and semi-polar (i.e. (20.1)-plane) wafers by ammonothermal method. The growth method and polishing results are described. We succeeded in producing 26 mm × 26 mm non- and semi-polar wafers. These wafers possess outstanding structural and optical properties, with threading dislocation density of the order of ...
Wafer-scale arrays of well-ordered Pb(Zr0.2Ti0.8)O3 nanodiscs and nanorings were fabricated on the entire area (10 mm × 10 mm) of the SrRuO3 bottom electrode on an SrTiO3 single-crystal substrate using the laser interference lithography (LIL) process combined with pulsed laser deposition. The shape and size of the nanostructures were controlled by the amount of PZT deposited through the patterned ...
We investigated the transition energy levels of the vacancy defects in gallium nitride by means of a hybrid density functional theory approach (DFT). We show that, in contrast to predictions from a recent study on the level of purely local DFT, the inclusion of screened exchange stabilizes the triply positive charge state of the nitrogen vacancy for Fermi energies close to the valence band. On the...
The recent advances in epitaxial SiC films' growth on Si are overviewed. The basic classical methods currently used for SiC films' growth are discussed and their advantages and disadvantages are explored. The basic idea and the theoretical background for a new method of the synthesis of epitaxial SiC films on Si are given. It will be shown that the new method is significantly different from the cl...
It is still a great challenge for semiconductor based-devices to obtain a large magnetoresistance (MR) effect under a low magnetic field at room temperature. In this paper, the photoinduced MR effects under different intensities of illumination at room temperature are investigated in a semi-insulating gallium arsenide (SI-GaAs)-based Ag/SI–GaAs/Ag device. The device is subjected to the irradiation...