Controllable Ga catalyst deposition on GaN template and fabrication of ordered vertical β-Ga₂O₃ nanowire array

Abstract

Controllable deposition of Ga droplets on a GaN template is discussed in detail in the present work. It is found that the Ga droplet density shows apparent nonlinear dependence on the flux of triethylgallium under certain annealing conditions. A simplified model based on the weakening of cluster mobility is proposed to explain the phenomenon. In addition, based on the different mobility of Ga on different substrates, a SiO2 mask with ordered nanopore array is designed and optimized for controllable catalyst deposition. By further optimizing the deposition and annealing process, a higher filling rate of nanopores is obtained, and ordered β-Ga2O3 nanowire arrays perpendicular to substrates are then achieved. The controllable uniform vertical nanowire array would further promote optimization of nanowire growth and device fabrication.

Research of nanopore structure of Ga2O3 film in MOCVD for improving the performance of UV photoresponse

“…Previously, there have been studies on the preparation of Si films with nanopore arrays by reactive ion etching [20], but this method would produce lots of surface defects, affecting the device performance. In our research, when the provided metal was Ga only, it was found that during high temperature annealing, Ga on the surface of Ga 2 O 3 film did not migrate and aggregate like Ga on the surface of GaN template in our Ga 2 O 3 nanowire experiments [21], but in situ etched the surface of Ga 2 O 3 film to form nanopore structure. Patrick Vogt reported if the metal flux is provided in the absence of oxygen, the supplied metal atoms could etch the surface of the already grown oxide film [22].…”

A review of metal–semiconductor contacts for β-Ga2O3

“…Because of their large bandgaps, high breakdown voltages, large electron mobility, and good thermal stability, wide-gap semiconductors such as ZnO, SiC, and Ga 2 O 3 have been widely used in the fields of environmental monitoring, flame detection, chemical analysis, security communication, and so on [1][2][3][4]. Among all wide-gap semiconductors, owing to its unique ultra-large bandgap (4.6-4.9 eV), well-controlled doping, and availability of large-sized substrates, gallium oxide (Ga 2 O 3 ) has received more and more attention [5][6][7][8]. As * Authors to whom any correspondence should be addressed.…”

Facile synthesis of β–Ga2O3 nanowires network for solar-blind ultraviolet photodetector

“…For example, in 2014, Lopez et al prepared the Ga 2 O 3 powder tablet as the substrate by thermal evaporation and metal Ga as the catalyst, Ga 2 O 3 nanowires were grown at 1100 • C by thermal oxidation method, but the growth time was up to 10 h [17]. In 2020, Cao et al used gallium (Ga) as a catalyst to grow more regular Ga 2 O 3 nanowires with diameter and length of about 200 nm on different substrates, but the pretreatment process is relatively complicated [18]. In 2020, Guo et al used the hydrothermal method to grow β-Ga 2 O 3 on fluorine-doped tin oxide substrate with low reaction temperature (150 • C), but the constant temperature time needs 12 h and more annealing time of 4 h. The β-Ga 2 O 3 by hydrothermal method usually has a nanorod structure, compared with nanowires with a smaller specific surface area [19].…”