Abstract Growth of Si-doped AlN layers by hydride vapor phase epitaxy on AlN/sapphire templates prepared by metalorganic vapor phase epitaxy and bulk AlN substrates prepared by physical vapor transport was investigated using silicon tetrachloride (SiCl4) as a doping gas. On the AlN/sapphire templates, when the SiCl4 supply was low, the incorporation ratio of Si decreased due to the influence of O impurities resulting from the decomposition of the sapphire. In addition, pits were formed on the surfaces, and the pit density increased significantly at Si concentrations exceeding 2 × 1019 cm-3. In contrast, on the bulk AlN substrates, the Si concentration increased linearly with increasing SiCl4 supply, and a pit- and stress-free layer could be grown with a Si concentration as high as 6.5 × 1019 cm-3. Hall effect measurements revealed that this layer exhibited n-type conductivity with a donor activation energy of 253 meV. However, the carrier density at room temperature (RT) was as low as 3.6 × 1013 cm-3 because of the high compensation ratio due to the presence of acceptors. A broad peak centered at 3.3 eV was observed in the RT photoluminescence spectra of the Si-doped AlN layers grown on the bulk AlN substrates, indicating that Al vacancies formed by the Fermi level effect due to Si doping acted as acceptors that compensated for carriers.

中文翻译：

---

使用 SiCl4 作为掺杂气体的 Si 掺杂 AlN 层的氢化物气相外延

摘要 使用四氯化硅 (SiCl4) 作为掺杂气体，研究了通过氢化物气相外延在金属有机气相外延制备的 AlN/蓝宝石模板和物理气相传输制备的块状 AlN 衬底上生长 Si 掺杂的 AlN 层。在 AlN/蓝宝石模板上，当 SiCl4 供应量较低时，由于蓝宝石分解产生的 O 杂质的影响，Si 的掺入率降低。此外，在表面形成凹坑，当 Si 浓度超过 2 × 1019 cm-3 时，凹坑密度显着增加。相比之下，在块状 AlN 衬底上，Si 浓度随着 SiCl4 供应的增加而线性增加，并且可以在 Si 浓度高达 6.5 × 1019 cm-3 的情况下生长无凹坑和无应力层。霍尔效应测量表明，该层表现出 n 型导电性，供体激活能为 253 meV。然而，由于受主的存在导致高补偿率，室温（RT）下的载流子密度低至 3.6 × 1013 cm-3。在块体 AlN 衬底上生长的 Si 掺杂 AlN 层的 RT 光致发光光谱中观察到以 3.3 eV 为中心的宽峰，表明由 Si 掺杂引起的费米能级效应形成的 Al 空位充当了补偿载流子的受体。