发表机构
TU Wien; Silvaco Europe Ltd.（维也纳工业大学; Silvaco欧洲有限公司）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过分子动力学模拟揭示，Al注入4H-SiC在高温下形成故障环降低Al激活，而低温注入可提高激活效率。
AI 中文摘要
我们提出了一个关于4H-SiC中Al注入的分子动力学（MD）研究，以确定注入温度和剂量如何影响退火过程中的缺陷演化和掺杂剂激活。模拟采用Gao-Weber势，并配以重新参数化的Morse Al-SiC相互作用，该相互作用已针对密度泛函理论扩散和踢入/踢出势垒进行了校准。在Al浓度超过约2e20/cm3的饱和极限时，900 K下的注入促进了注入过程中富间隙平面团簇的形成。在退火过程中，这些团簇捕获Al并演变为故障间隙环，减少了替代位Al的掺入。相比之下，较低的注入温度保留了较强的局部无序，这些无序在外延再生长过程中被消耗，从而在MD可访问的退火时间内实现了更高的化学激活。原子轨迹显示，一旦平面团簇达到约60个间隙原子，就会发生热激活的向故障环的转变。并非作为单个相干盘成核，而是首先形成几个局部故障区域，随后合并。位错成核的激活能约为1.1 eV，层错生长的激活能约为2.1 eV。Frank型环在高温下占主导地位，而瞬态Shockley分位错主要出现在早期阶段且低于2000 K。随着大平面缺陷的形成和溶解，稳定的补偿Al-C络合物也会出现。这些发现支持了实验假设，即二次缺陷有助于在退火过程中过饱和条件下观察到的Al激活降低。
英文摘要
We present a molecular dynamics (MD) study of Al implantation in 4H-SiC to determine how implantation temperature and dose affect defect evolution and dopant activation during annealing. Simulations use the Gao-Weber potential with a Morse Al-SiC interaction reparameterized to density functional theory diffusion and kick-in/kick-out barriers. At Al concentrations above the saturation limit of ~2e20/cm3, implantation at 900 K promotes interstitial-rich planar clusters already during implantation. During annealing, these clusters trap Al and evolve into faulted interstitial loops, reducing substitutional Al incorporation. In contrast, lower implantation temperatures preserve stronger local disorder that is consumed during epitaxial regrowth, resulting in higher chemical activation within MD-accessible annealing times. Atomistic trajectories show a thermally activated transition to faulted loops once planar clusters reach about 60 interstitials. Rather than nucleating as a single coherent disk, several locally faulted regions form first and subsequently merge. The activation energy is ~1.1 eV for dislocation nucleation and ~2.1 eV for stacking-fault growth. Frank-type loops dominate at high temperature, while transient Shockley partials occur mainly at early stages and below 2000 K. As large planar defects form and dissolve, stable compensating Al-C complexes also emerge. These findings support the experimental hypothesis that secondary defects contribute to the reduced Al activation observed under supersaturation during annealing.
