Heteroepitaxial Growth of an Ultrathin β-Ga₂O₃ Film on a Sapphire Substrate Using Mist CVD with Fluid Flow Modeling

Abstract

β-Gallium oxide (Ga2O3) has received intensive attention in the scientific community as a significant high-power switching semiconductor material because of its remarkable intrinsic physical characteristics and growth stability. This work reports the heteroepitaxial growth of the β-Ga2O3 ultrathin film on a sapphire substrate via mist chemical vapor deposition (CVD). This study used a simple solution-processed and nonvacuum mist CVD method to grow a heteroepitaxial β-Ga2O3 thin film at 700 °C using a Ga precursor and carrier gases such as argon and oxygen. Various characterization techniques were used to determine the properties of the thin film. Additionally, a computational study was performed to study the temperature distribution and different mist velocity profiles of the finite element mist CVD model. This simulation study is essential for investigating low to high mist velocities over the substrate and applying low velocity to carry out experimental work. XRD and AFM results show that the β-Ga2O3 thin film is grown on a sapphire substrate of polycrystalline nature with a smooth surface. HR-TEM measurement and UV–visible transmission spectrometry demonstrated heteroepitaxial β-Ga2O3 in an ultrathin film with a band gap of 4.8 eV.

Recent Advancements in α‐Ga2O3 Thin Film Growth for Power Semiconductor Devices via Mist CVD Method: A Comprehensive Review

“…[86,87] Hot-wall mist CVD effectively produces highquality 𝛼-Ga 2 O 3 thin films on c-sapphire substrates because of the long vaporization period of the mist droplet (Figure 6). [88,90] The mist CVD system comprises three units: supply, reaction, and exhaust. A gallium precursor was prepared by dissolving 0.01 mol of gallium acetylacetonate (0.367 gm) into 100 mL of distilled water (DI).…”

“…Mist floats in the air and evaporates which is suitable for controlling precursor movement under ambient pressure. [88,90] Inside the reaction chamber, vapor-coated particles can adhere to the high-temperature substrate and undergo chemical reactions on the surface. The frequency of the atomization unit significantly influences the size of the particles.…”

From wide to ultrawide-bandgap semiconductors for high power and high frequency electronic devices

“…While the aforementioned growth methods are currently the leading techniques and attract significant research interest in Ga 2 O 3 epitaxy, additional growth methods, including low pressure chemical vapor deposition (LPCVD) [385][386][387][388], mist chemical vapor deposition (Mist-CVD) [389][390][391], liquid injection metalorganic chemical vapor deposition (LI-MOCVD) [351,392], and pulsed laser deposition (PLD) [393,394], have offered epitaxial Ga 2 O 3 films of comparable film qualities with the benefits of relatively low deposition temperatures, large carrier concentration ranges, high deposition rates and relatively inexpensive deposition equipment. Lastly, heteroepitaxy of Ga 2 O 3 device structures on more thermally conductive foreign substrates for heat mitigation employs epitaxial growth methods described in this section.…”

A correlation of conductivity medium and bioparticle viability on dielectrophoresis‐based biomedical applications

“…The electrode's shape, size, and position in the channel produce a nonuniform electric field gradient [59]. Metals, for instance, gold (Au), silver (Ag), chromium (Cr), platinum (Pt), and titanium (Ti), are commonly used to implement electrode geometries [60][61][62]. Which includes planar [63,64], interdigitated [65,66], quadrupole [3], tapered [45,[67][68][69][70][71][72][73], rectangular [74], curved [75], and spiral electrodes [4,35].…”