High Mg activation in implanted GaN by high temperature and ultrahigh pressure annealing
High Mg activation in implanted GaN by high temperature and ultrahigh pressure annealing
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DOI：
10.1063/5.0038628
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发表时间：
2021-01-11
影响因子：
4
通讯作者：
Sitar, Zlatko
中科院分区：
文献类型：
--
作者：
Breckenridge, M. Hayden;Tweedie, James;Sitar, Zlatko
我们在镁注入的 GaN 中展示了高 p 型电导率和 >10(18)cm(-3) 的空穴浓度。注入在室温下进行，并在 1GPa 的 N-2 和 1200-1400 摄氏度的温度范围内进行注入后退火。高压热力学稳定了 GaN 表面，无需覆盖层。我们引入了与扩散长度相关的“扩散预算”，作为比较在不同温度和不同时间退火的样品的便捷工程参数。尽管通过 XRD 测量的损伤恢复是在相对较低的扩散预算下实现的，但这些样品并未表现出 p 型导电性。进一步的分析显示植入引起的缺陷的严重补偿。较高的扩散预算导致较低的 Mg 电离能（类似于 115meV）和几乎完全的 Mg 激活。对于更高的扩散预算，我们观察到 Mg 显着损失到表面，并且空穴电导率相应降低。低扩散预算下的高补偿和高扩散预算下的镁损失对浅注入提出了独特的挑战。为了实现空穴传导性和低镁扩散，可能需要直接控制由注入损伤引起的补偿缺陷的形成。
We demonstrate high p-type conductivity and hole concentrations >10(18)cm(-3) in Mg-implanted GaN. The implantation was performed at room temperature and by post-implantation annealing at 1GPa of N-2 and in a temperature range of 1200-1400 degrees C. The high pressure thermodynamically stabilized the GaN surface without the need of a capping layer. We introduce a "diffusion budget," related to the diffusion length, as a convenient engineering parameter for comparing samples annealed at different temperatures and for different times. Although damage recovery, as measured by XRD, was achieved at relatively low diffusion budgets, these samples did not show p-type conductivity. Further analyses showed heavy compensation by the implantation-induced defects. Higher diffusion budgets resulted in a low Mg ionization energy (similar to 115meV) and almost complete Mg activation. For even higher diffusion budgets, we observed significant loss of Mg to the surface and a commensurate reduction in the hole conductivity. High compensation at low diffusion budgets and loss of Mg at high diffusion budgets present a unique challenge for shallow implants. A direct control of the formation of compensating defects arising from the implantation damage may be necessary to achieve both hole conductivity and low Mg diffusion.