标题： LPCVD 生长的 Si 掺杂$β$-Ga$_2$O$_3$薄膜，具有良好的电子迁移率 显示英文标题

标题： LPCVD Grown Si-Doped $β$-Ga$_2$O$_3$ Films with Promising Electron Mobilities

摘要： 我们系统地研究了使用LPCVD系统生长的Si掺杂的$\beta$-Ga$_2$O$_3$薄膜，分别在载流子浓度为$1.51 \times 10^{17}$cm$^{-3}$和$1.15 \times 10^{17}$cm$^{-3}$时实现了162cm$^2$/V.s和149cm$^2$/V.s的高电子迁移率，对于在$\beta$-Ga$_2$O$_3$衬底上生长的同质外延(010)$\beta$-Ga$_2$O$_3$薄膜以及在偏轴c蓝宝石衬底上生长的异质外延(-201)$\beta$-Ga$_2$O$_3$薄膜，其偏切角为6{\deg }，代表了目前报道的LPCVD生长的$\beta$-Ga$_2$O$_3$材料中的最高迁移率。 载流子浓度通过在1000{\deg }C的生长温度下改变SiCl$_4$的流量精确调节， resulting in concentrations ranging from$1.15 \times 10^{17}$to$1.19 \times 10^{19}$cm$^{-3}$，并通过霍尔和C-V测量得到确认。 这些薄膜表现出高质量的晶体结构，通过高分辨率XRD和拉曼光谱得到确认，表明相纯度和结构完整性。 通过FESEM和AFM成像表征的表面形貌显示，载流子浓度与表面光滑度之间存在强相关性，较低的浓度导致RMS粗糙度降低。 SIMS分析显示硅的均匀掺入，碳、氢和氯的杂质含量低于检测限，表明薄膜具有高纯度。 在80 K时，(-201)$\beta$-Ga$_2$O$_3$薄膜的低温峰值迁移率超过843 cm$^2$/V$\cdot$s，突显了这些薄膜的高纯度和低补偿。 这些发现强调了LPCVD生长系统在生产高纯度$\beta$-Ga$_2$O$_3$薄膜方面的潜力，其厚度范围在约2.3-11.7$\mu$m之间，生长速率较快（约4.7-17$\mu$m/小时），具有良好的传输特性、可控制的掺杂以及可扩展性，适用于开发高功率垂直器件。 显示英文摘要

摘要： We systematically investigated the growth of Si-doped $\beta$-Ga$_2$O$_3$ films using LPCVD system, achieving high electron mobilities of 162 cm$^2$/V.s and 149 cm$^2$/V.s at carrier concentrations of $1.51 \times 10^{17}$ cm$^{-3}$ and $1.15 \times 10^{17}$ cm$^{-3}$, respectively, for homoepitaxial (010) $\beta$-Ga$_2$O$_3$ films grown on $\beta$-Ga$_2$O$_3$ substrates and heteroepitaxial (-201) $\beta$-Ga$_2$O$_3$ films grown on off-axis c-sapphire substrates with 6{\deg} miscut, representing the highest mobilities reported for LPCVD-grown $\beta$-Ga$_2$O$_3$ materials. Carrier concentrations were precisely tuned by varying SiCl$_4$ flow rates at a growth temperature of 1000{\deg}C, resulting in concentrations ranging from $1.15 \times 10^{17}$ to $1.19 \times 10^{19}$ cm$^{-3}$, as confirmed by both Hall and C-V measurements. The films exhibited high crystalline quality, confirmed by high-resolution XRD and Raman spectroscopy, indicating phase purity and structural integrity. Surface morphologies characterized by FESEM and AFM imaging showed a strong correlation between carrier concentrations and surface smoothness, with lower concentrations resulting in reduced RMS roughness. SIMS analysis revealed uniform Si incorporation, with low carbon, hydrogen, and chlorine impurities below detection limits, indicating high purity of the films. A high low-temperature peak mobility exceeding 843 cm$^2$/V$\cdot$s was achieved for (-201) $\beta$-Ga$_2$O$_3$ films at 80 K, highlighting the high purity and low compensation of these films. These findings emphasize the potential of LPCVD growth system for producing high-purity $\beta$-Ga$_2$O$_3$ films with thickness ranging between ~2.3-11.7 $\mu$m and faster growth rates (~4.7-17 $\mu$m/hr), promising transport properties, controllable doping, and scalability for developing high power vertical devices.