Nishinaka Hiroyuki, Kajita Yuki, Hosaka Shoma, Miyake Hiroki
Faculty of Electrical Engineering and Electronics, Kyoto Institute of Technology, Kyoto, Japan.
Department of Electronics, Kyoto Institute of Technology, Kyoto, Japan.
Sci Technol Adv Mater. 2024 Oct 16;25(1):2414733. doi: 10.1080/14686996.2024.2414733. eCollection 2024.
This study investigates the compositional analysis and growth of β-(In Ga )O thin films on (010) β-GaO substrates using mist chemical vapor deposition (CVD), including the effects of the growth temperature. We investigated the correlation between In composition and -axis length in coherently grown films, vital for developing high-electron-mobility transistors and other devices based on β-(In Ga )O. Analytical techniques, including X-ray diffraction (XRD), reciprocal space mapping, and atomic force microscopy, were employed to evaluate crystal structure, strain relaxation, and surface morphology. The study identified a linear relationship between In composition and -axis length in coherently grown films, facilitating accurate composition determination from XRD peak positions. The films demonstrated high surface flatness with root-mean-square roughness below 0.6 nm, though minor relaxation and granular features emerged at higher In compositions ( = 0.083) at the growth temperature of 750°C. XRD results revealed that lattice relaxation were observed at a growth temperature of 700°C despite low In composition. In contrast, at 800°C, the In composition was higher than at 750°C, and coherent growth was achieved. The surface morphology was the flattest at 750°C. These findings indicate that the growth temperature plays a crucial role in the mist CVD growth of β-(In Ga )O thin films. This study offers insights into the relationship between In composition and lattice parameters in coherently grown β-(In Ga )O films, as well as the effect of growth conditions, contributing to the advancement of ultra-wide bandgap semiconductor device development.
本研究利用雾态化学气相沉积（CVD）法，研究了在（010）β-Ga₂O₃衬底上β-（InₓGa₁₋ₓ）₂O₃薄膜的成分分析和生长情况，包括生长温度的影响。我们研究了在相干生长的薄膜中In成分与c轴长度之间的相关性，这对于开发基于β-（InₓGa₁₋ₓ）₂O₃的高电子迁移率晶体管和其他器件至关重要。采用了包括X射线衍射（XRD）、倒易空间映射和原子力显微镜在内的分析技术来评估晶体结构、应变弛豫和表面形貌。该研究确定了相干生长薄膜中In成分与c轴长度之间的线性关系，便于从XRD峰位置准确确定成分。薄膜表现出高表面平整度，均方根粗糙度低于0.6nm，不过在750°C的生长温度下，当In成分较高（x = 0.083）时会出现轻微的弛豫和颗粒特征。XRD结果表明，尽管In成分较低，但在700°C的生长温度下仍观察到晶格弛豫。相比之下，在800°C时，In成分高于750°C时，并且实现了相干生长。表面形貌在750°C时最平整。这些发现表明，生长温度在β-（InₓGa₁₋ₓ）₂O₃薄膜的雾态CVD生长中起着关键作用。本研究深入了解了相干生长的β-（InₓGa₁₋ₓ）₂O₃薄膜中In成分与晶格参数之间的关系，以及生长条件的影响，有助于推动超宽带隙半导体器件的发展。
