论文标题
为$ al_xga_ {1-x} n $外尾设计低成本TAC虚拟基板
Designing low-cost TaC virtual substrates for $Al_xGa_{1-x}N$ epitaxy
论文作者
论文摘要
$ al_xga_ {1-x} n $是光电子学的关键超宽带盖材料，但是由于缺乏晶格匹配的底物，厚实，高质量的外延层的沉积受到了阻碍。在这里，我们将过渡金属碳化物的面孔（111）视为合适的材料类别的材料，适用于（0001）$ al_xga_ {1-x} n $，并展示了薄膜TAC的增长，该薄膜TAC具有有效的六边形晶格，与$ al_ {0.45} ga__ {0.45} ga__ {0.45} ga_ {0.55} n $。我们探索溅射TAC在蓝宝石底物上的生长条件，并研究溅射功率，层厚度和入射等离子体角度对膜结构以及平面外应变的影响。然后，我们通过以1600 $^\ Circ $ C的面对面配置在面对面配置中退火来表现出对膜质量的关键改进，该胶片在最大最大（FWHM）内和平面外衍射峰的最大宽度大大降低，并导致步骤和terrace表面表面形态。这项工作为$ al_xga_ {1-x} n $ heteroepitaxy的导电，晶格匹配的，热兼容的底物提供了一条途径，这是垂直设备和其他电源电子应用的关键步骤。
$Al_xGa_{1-x}N$ is a critical ultra-wide bandgap material for optoelectronics, but the deposition of thick, high quality epitaxial layers has been hindered by a lack of lattice-matched substrates. Here we identify the (111) face of transition metal carbides as a suitable class of materials for substrates lattice matched to (0001) $Al_xGa_{1-x}N$ and demonstrate the growth of thin film TaC which has an effective hexagonal lattice constant matched to $Al_{0.45}Ga_{0.55}N$. We explore growth conditions for sputtered TaC on sapphire substrates and investigate the effects of sputter power, layer thickness and incident plasma angle on film structure and in- and out-of-plane strain. We then show critical improvements to film quality by annealing films in a face-to-face configuration at 1600 $^\circ$C, which significantly reduces full width at half max (FWHM) of in- and out-of-plane diffraction peaks and results in a step-and-terrace surface morphology. This work presents a path toward electrically conductive, lattice matched, thermally compatible substrates for $Al_xGa_{1-x}N$ heteroepitaxy, a critical step for vertical devices and other power electronics applications.
