The article aims to investigate the effect of doping source temperature on the crystal quality of thin films. By changing the temperature of the tin source, a single crystal gallium oxide film was deposited on C -plane sapphire using the MOCVD. The results indicate that the decrease in tin source temperature makes it easier for tin atoms to replace Ga atoms at lattice sites and reduces damage to the lattice. At -20 celcius tin source, the doped thin film not only had minimum full width at half maxima of 2.04 degrees and a roughness of 4.45 nm, but also the ratio of photocurrent to dark current of the photodetector reached the highest of 526, and the rise and fall time responses achieved the lowest of 4.81 s and 5.24 s, respectively. Our work can optimize the crystal quality of doped thin films and the photodetectors performance by controlling the tin source temperature.

This article innovatively uses pulsed metal-organic chemical vapor deposition technology to optimize the quality of β-Ga2O3 thin films on (−201) β-Ga2O3 homo-substrate using indium pulse-assisted technology. The results demonstrate that the pulsed indium-assisted method, when compared with the traditional indium-assisted method, effectively suppresses the desorption of Ga2O, enhances the flatness of the β-Ga2O3 film, and reduces the surface roughness from 34.8 to 0.98 nm. The optimized single crystalline β-Ga2O3 film was grown with pulsed-indium, and the full width at half maximum of x-ray diffraction rocking curve was 30.42 arc sec, smaller than that of the continuous indium β-Ga2O3 (56.1 arc sec). In combination with the x-ray photoelectron spectroscopy O1s split-peak fitting analysis, the relative content of oxygen vacancies in the film was significantly reduced by pulsed indium-assisted method. The Hall mobility of films assisted by pulsed-indium is approximately 14 times higher than that of films assisted by traditional indium. The pulsed indium technology provides an idea for homoepitaxial growth of high-quality β-Ga2O3 films.

Pulsed Sn doping (PSD) homoepitaxial gallium oxide (Ga2O3) films were deposited on (-201) beta-Ga2O3 substrates using metal-organic chemical vapor deposition (MOCVD). The study aims to optimize Sn doping conditions to enhance the electrical properties of beta-Ga2O3 films. The influence of Sn pulse width (ranging from 0.1 min to 0.3 min) on the morphology, structure, and electrical properties of the film was investigated. The Full Width at Half Maximum (FWHM) of the (-201) crystal plane rocking curve for all doped films is <50 arcsec, indicating high crystal quality. At a Sn pulse width of 0.2 min, we achieve the optimal balance between doping efficiency and crystal quality, resulting in a resistivity of 0.0487 Omegacm, an electron mobility of 63.5 cm(2)/Vs, and a carrier concentration of 1.82 x 10(18) cm(-3). Compared to continuous Sn doping, PSD results in approximately 157 % increase in carrier concentration and 99 % increase in electron mobility. The application of PSD allows sufficient diffusion time for Sn atoms to effectively incorporate into the film, signifying a crucial advancement in enhancing the film's electrical properties and reducing the cost of the metal organic doping source.

In this work, the Metal-organic Chemical Vapor Deposition (MOCVD) technology was used to successfully grow Si-doped beta-Ga2O3 films on C-plane sapphire substrates. The effects of Si flow rate on the surface morphology, crystal composition, electrical and optical properties of the films were characterized and analyzed. The experimental results show that the full width at half maximum (FWHM) and root mean square (RMS) of the films are improved with the decrease of Si flow rate. More importantly, only the sample with the lowest Si flow rate showed conductive ability, and its carrier concentration and mobility were 4.20 cm(2)/V center dot s and 3.33 x 10(16) cm(-3), respectively. In addition, we also made photodetectors corresponding to the thin films. The test results showed that the external quantum efficiency (EQE) and responsiveness (R) of the detectors improved with the decrease of Si flow rate.

In this study, thin films of Ga2O3 were fabricated on sapphire substrates utilizing metal-organic chemical vapor deposition technology, with deposition conducted at a temperature of 400 degrees C. The investigation focused on examining the influence of oxygen on the surface morphology, phase transition, and optical characteristics of Ga2O3 films synthesized at relatively low temperatures. X-ray diffraction tests indicated that all films were polycrystalline and had mixed beta and epsilon phases. With an increase in oxygen flow rate from 1400 to 1800 sccm, beta-Ga2O3 became the dominant material. Atomic force microscope analysis showed that the root-mean-square roughness had decreased. Film thicknesses, as measured by scanning electron microscopy, were 285.3, 257.6, 243.2, and 254.2 nm, respectively. The high-resolution transmission electron microscope confirmed a mixed-phase structure at an oxygen rate of 2100 sccm. Moreover, the X-ray photoelectron spectroscopy results show that increasing the oxygen flow rate from 1400 to 1800 sccm is effective in reducing the oxygen vacancies and defects in the films. However, excessive oxygen flow (2100 sccm) leads to the exacerbation of prereaction and the deterioration of the film's crystalline quality.

In the field of wide-bandgap semiconductors, fabricating high quality beta-Ga2O3 films on heterogeneous substrates remains a tremendous challenge. This article innovatively uses pulsed metal-organic chemical vapor deposition (MOCVD) technology to optimize the quality of beta-Ga2O3 thin film on sapphire substrates using indium pulse-assisted technology. The findings indicate that full width at half maximum of the (-201) beta-Ga2O3 crystal plane orientation is reduced by 2700 arcsec after pulsed indium-assisted. The addition of pulsed indium atoms effectively suppresses the desorption of low oxide Ga2O, improving the flatness of beta-Ga2O3 films surface and reduced the surface roughness from 30.1 nm to 5.4 nm. Moreover, the UV-Visible transmittance of the film exceeds 80%, accompanied by an increase in bandwidth. In combination with the XPS O1s split-peak fitting analysis, the quality of the films was optimized by using pulsed indium-assisted, resulting in a reduction in the relative content of oxygen vacancies in the film. The pulsed indium technology provides a new idea for heteroepitaxy growth of high quality beta-Ga2O3 films.

In this paper, the method for growing α-Ga2O3 films on c-plane sapphire substrates using an inexpensive fine-channel mist-CVD face-to-face heating plate was investigated. Because high temperatures can result in reactor deformation, expensive AlN ceramics resistant to deformation are used as the reactor fabrication material in traditional fine-channel mist-CVD equipment, which limits its use for promotion and research purposes. In this work, we used a face-to-face heating method to replace the traditional single-sided heating method which will reduce the requirement for equipment sealability. Therefore, cheap quartz can be used to replace expensive AlN ceramics to make reactors, which can greatly reduce the cost of mist-CVD equipment. We also investigated the effects of substrate temperature and carrier gas on the crystalline quality and surface morphology of α-Ga2O3 films. By optimizing the fabrication conditions, we obtained triangular grains with edges that were clearly visible in atomic force microscopy images. Using absorption spectrum analysis, we also found that the optical bandgap of the film reached 5.24 eV. Finally, we recorded a value of 508 arcsec for the full width at half maximum of the α-Ga2O3 (0006) diffraction peak in the X-ray diffraction pattern.