低压化学气相沉积（LPCVD）生长的(010)β-氧化镓（β-Ga₂O₃）薄膜中的锡掺杂
Sn-Doping in LPCVD-Grown (010) $β$-Ga$_2$O$_3$ Films
AI总结：
本研究通过LPCVD生长锡掺杂(010)β-Ga₂O₃同质外延薄膜，实现可控掺杂与厚层制备，获最高迁移率，为厚漂移层制备提供可行途径。
AI中文摘要：
本研究通过低压化学气相沉积（LPCVD）生长了锡掺杂的(010)β-氧化镓（β-Ga₂O₃）同质外延薄膜，系统研究了锡掺入对薄膜结构、形貌和电学性能的影响。实现了可控的室温载流子浓度，范围为1.17×10¹⁷至3.06×10¹⁸ cm⁻³，对应的霍尔迁移率从113 cm² V⁻¹ s⁻¹降至63 cm² V⁻¹ s⁻¹。这些薄膜呈现单斜晶系β-Ga₂O₃相，化学计量比接近，具有清晰的台阶流形貌，摇摆曲线半高宽（FWHM）最小为68.4角秒，均方根（RMS）粗糙度为2.63 nm。在6.4至16.6 μm h⁻¹的生长速率下，获得了厚度范围为1.66至11.3 μm的薄膜，证明了LPCVD制备厚外延层的能力。室温载流子浓度为1.17×10¹⁷ cm⁻³的样品，其室温霍尔迁移率为113 cm² V⁻¹ s⁻¹，84 K低温下的霍尔迁移率为380 cm² V⁻¹ s⁻¹，这两个数值均为LPCVD生长的锡掺杂β-Ga₂O₃的最高报道值。对该样品的输运建模得到浅施主激活能为32.7 meV，深施主能级为95 meV，补偿受主浓度低至2.0×10¹⁶ cm⁻³，表明施主激活效率高，补偿程度低。这些结果表明，LPCVD可实现可控的锡掺杂，同时保持优异的结构和电学性能，为制备厚β-Ga₂O₃外延漂移层提供了可行途径。
英文摘要：
In this work, Sn-doped (010) $β$-Ga$_2$O$_3$ homoepitaxial films were grown by low-pressure chemical vapor deposition (LPCVD), and the influence of Sn incorporation on their structural, morphological, and electrical properties was systematically investigated. Controlled room-temperature carrier concentrations ranging from $1.17 \times 10^{17}$ to $3.06 \times 10^{18}$ cm$^{-3}$ were achieved, with corresponding Hall mobilities decreasing from 113 to 63 cm$^2$ V$^{-1}$ s$^{-1}$. The films exhibited the monoclinic $β$-Ga$_2$O$_3$ phase, near-stoichiometric composition, and well-defined step-flow morphology, with a minimum rocking-curve FWHM of 68.4 arcsec and an RMS roughness of 2.63 nm. Film thicknesses ranging from 1.66 to 11.3 $μ$m were obtained at growth rates of 6.4 to 16.6 $μ$m h$^{-1}$, demonstrating the ability of LPCVD to produce thick epitaxial layers. The sample with a room-temperature carrier concentration of $1.17 \times 10^{17}$ cm$^{-3}$ exhibited room-temperature and low-temperature Hall mobilities of 113 cm$^2$ V$^{-1}$ s$^{-1}$ and 380 cm$^2$ V$^{-1}$ s$^{-1}$ at 84 K, respectively. Both represent the highest reported values for LPCVD-grown Sn-doped $β$-Ga$_2$O$_3$. Transport modeling of the same sample yielded a shallow donor activation energy of 32.7 meV, a deeper donor level at 95 meV, and a low compensating acceptor concentration of $2.0 \times 10^{16}$ cm$^{-3}$, indicating efficient donor activation and a low degree of compensation. These results demonstrate that LPCVD enables controlled Sn doping while maintaining excellent structural and electrical quality, providing a viable route for realizing thick $β$-Ga$_2$O$_3$ epitaxial drift layers.
