Abstract A magnetron sputtered AlN buffer layer is applied for preparing 2 in. free-standing (FS) GaN on the GaAs substrate by hydride vapor phase epitaxy (HVPE). The AlN buffer layer with excellent compactness can prevent As atoms from diffusing to the GaN growth surface. Thus it serves as an effective protective layer for GaAs substrate and also a seed layer for the deposition of GaN in the early stage of the high-temperature GaN growth. Benefiting from the decomposition property of GaAs at temperature higher than 900 °C, thick GaN film self-separated completely from GaAs substrate during growth. By this way, a 2 in. FS-GaN layer with the thickness of 1.3 mm is finally obtained after the long growth time about 20 h.

中文翻译：

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通过 HVPE 在 GaAs 衬底上使用溅射的 AlN 缓冲层生长 2 英寸独立式 GaN

摘要 应用磁控溅射的 AlN 缓冲层，通过氢化物气相外延 (HVPE) 在 GaAs 衬底上制备 2 英寸自支撑 (FS) GaN。具有优异致密性的 AlN 缓冲层可以防止 As 原子扩散到 GaN 生长表面。因此，它可以作为 GaAs 衬底的有效保护层，也是在高温 GaN 生长早期沉积 GaN 的种子层。受益于 GaAs 在 900 °C 以上的分解特性，厚 GaN 膜在生长过程中与 GaAs 衬底完全自分离。通过这种方式，经过大约20小时的长生长时间，最终得到厚度为1.3mm的2英寸FS-GaN层。