Gallium oxide (Ga₂O₃) thin films were grown on c-, a-, m-, r-plane sapphire substrates using a mist chemical vapor deposition system. Various growth temperature range of 400~600℃ was applied for Ga₂O₃ thin film deposition. Then, several structural properties were characterized such as film thickness, crystal phase, lattice orientation, surface roughness, and optical bandgap. Under the certain growth temperature of 500℃, all grown Ga₂O₃ featured rhombohedral crystal structures and well-aligned preferred orientation to sapphire substrate. The films grown on c-and r-plane sapphire substrates, showed low surface roughness and large optical bandgap compared to those on a-and m-plane substrates. Therefore, various sapphire orientation can be potentially applicable for future Ga₂O₃-based electronics applications.

Herein, for the quantitative analysis of the arc beads related to electric fire, we used electron backscatter diffraction (EBSD), a measuring device for grain orientation of materials, we compared and analyzed the surface texture of primary and secondary beads according to the difference in cooling rate at ambient temperature. This analysis revealed that the primary beads showed similar distribution at both low and high angles, while the secondary beads showed a higher distribution at low angles than at high angles. Thus, EBSD can be used for quantitative analysis of the beads and can be applied to identify beads in the future.

In this paper, the growing orientation of PMN-PT single crystal is analyzed using the Laue-Back Reflection Method. Two kinds of PMN-PT single crystals are grown using the Bridgman growing method in the [001] and [111] directions and their the Laue photographs are simulated assuming cubic crystal systems. From the comparison between simulation and test results, it can be concluded that the single crystals are grown in the desired crystal orientations.

SiC crystal ingots were grown on 6H-SiC dual-seed crystals with different surface roughness and different seed orientation by a PVT (Physical Vapor Transport) method. 4H and 15R-SiC were grown on seed crystal with high root-mean-square (rms) value. The polytype of grown crystal on the seed crystal with lower rms value was confirmed to be 6H-SiC. On the other hand, all SiC crystals grown on seed crystals with different seed orientation were proven to be 6H-SiC. The surface roughness of seed crystals had no effect on the crystal structure of the grown crystals. However, the crystal quality of 6H-SiC single crystals grown on the on-axis seed were revealed to be slightly better than that of 6H-SiC crystal grown on the off-axis seed.

Citations

• Dislocation defects in 4H‑SiC crystals grown by physical vapor transport: Evolution, origins, and control strategies
  Peng Gu, Tianle Wang, Zefeng Guan, Jiliang Zhu
  Journal of Materials Science & Technology.2027; 287: 232.     CrossRef
• Reducing the Cut-In Voltage of a Silicon Carbide/p-Silicon Heterojunction Diode Using Femtosecond Laser Ablation
  Asghar Ali, Piotr A. Piatkowski, Hussain Alawadhi, Ali S. Alnaser
  ACS Applied Electronic Materials.2022; 4(12): 6076.     CrossRef

ZnO nanowires on the a-, c- and m-plane oriented 4H-SiC substrates were grown by using a high temperature tube furnace, Ti/Au electrodes were deposited on ZnO nanowires and a-, c- and m-plane 4H-SiC substrates, respectively. The shape and density of the ZnO nanowires were inestigated by field emission scanning electron microscope. It was found that the growth direction of nanowires depends strongly on growth parameters such as growth temperature and pressure. In this work, The sensitivity of nanowires formed a-, c- and m-plane oriented 4H-SiC gas sensor was measured at 300℃ with CO gas concentration of 80%. The nanowires grown on a-plane oriented 4H-SiC show improved performance than those on c- and m-plane oriented 4H-SiC due to the increased density of nanowire on a plane 4H-SiC.

AlN thin films were deposited on p-type Si(100) substrates by RF magnetron sputtering method. This study showed the change of the preferential orientation of AlN thin films deposition with the change of the deposition conditions such as sputtering pressure and Ar/N2 gas ratio in chamber. It was identified by X-ray diffraction patterns that AlN thin film deposited at low sputtering pressure has a (002) orientation, however its preferred orientation was changed from the (002) to the (100) orientation with increasing sputtering pressure. Also, it was observed that the properties of AlN thin films such as thickness, grain size and surface roughness were largely dependent on Ar/N2 gas ratio and a high quality thin film could be prepared at lower nitrogen concentration. AlN thin films were investigated relationship between preferential orientation and deposition condition by using XRD, FE-SEM and PFM.

ZnO thin films were deposited on a-, c- and m- plane oriented 4H-SiC substrates by pulsed laser deposition. ZnO nanowires were formed on substrates by tube furnace. Shape and density of the ZnO nanowires were investigated by field emission scanning electron microscope. Average surface roughness and root mean square surface roughness were measure by atomic force microscope. Optical properties were investigated by Photoluminescence measurement. Density of ZnO nanowires grown on a-, c- and m-plane oriented 4H-SiC substrates were 17.89 μm-2, 9.98 μm-2 and 2.61 μm-2, respectively.

ZnO is an n-type semiconductor with a wide band gap near 3.37 eV. It was known that ZnO films with a resistivity of the order of 10(-4) Ωcm is not easy to obtain. 1, 3, and 5wt% Si element were added into ZnO in ordre to improve the electrical and optical characteristics. The Si-doped ZnO (SZO) was grown on a glass substrate by radio frequency (RF) magnetron sputtering at the temperature range from 100 to 500℃. X-ray diffraction (XRD) patterns of SZO film showed preferable crystal orientation of (002) plane. It was confirmed that the lowest resistivity of the SZO films was 2.44≠10(-3) Ωcm and SZO films were significantly influenced by the working temperature. The average transmittance of the films was over 80% in the visible ranges.

ZnO with the wide band gap near 3.37 eV is typically an n-type semiconductor in which deviation from stoichiometry is electrically active. It was known that the films with a resistivity of the order of 10-4 Ωcm is not easy to obtain. In order to improve electrical characteristic of ZnO, we added 1, 3, 5 wt% Ga element in ZnO. The Ga-doped ZnO (GZO) was grown on a glass substrate by radio frequency (RF) magnetron sputtering at the temperature range from 100 to 500℃. X-ray diffraction (XRD) patterns of GZO films showed preferable crystal orientation of (002) plane. The lowest resistivity of the GZO films was 8.9×10-4 Ωcm. GZO films significantly influenced by the working temperature. The average transmittance of the films was over 80% in the visible ranges.

Citations

• Dependences of Sputtering Times on the Structural and Electrical Properties of ZnO/Ag/ZnO Thin Films on PET by DC Sputtering
  Yun-Hae Kim, Jin-Woo Lee, Ri-Ichi Murakami
  IEEE Transactions on Nanotechnology.2013; 12(6): 991.     CrossRef