通过横截面扫描隧道显微镜可视化三元III-V族半导体(Al,Ga)Sb的原子级组成
Atomic-scale composition of the ternary III-V semiconductor (Al,Ga)Sb visualized by cross-sectional scanning tunneling microscopy
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中文总结 AI 辅助
该研究用5 K横截面扫描隧道显微镜对分子束外延生长的(Al,Ga)Sb进行原子级分析，发现其阳离子呈随机分布，具有极高原子级均匀性。
中文摘要 AI 辅助
采用5 K下的横截面扫描隧道显微镜，通过在(1-10)和(110)解理面处直接原子计数，研究分子束外延生长的(Al,Ga)Sb层中的阳离子混合。Al和Ga表面阳离子间的电子对比，可对沿闪锌矿(001)表面内不等价的<110>方向以及沿[001]生长方向的金属亚晶格进行统计分析。发现阳离子沿生长方向和生长平面内均呈随机分布，无长程有序或各向异性生长动力学的证据；值得注意的是，沿两个平面内方向的同类型连续阳离子的平均数量相等，这可能是由于对随机分布的次表面阳离子进行统计平均所致。该结果与生长前沿阳离子掺入时的应变介导相互作用，或理想的无关联阳离子混合均相符。总体而言，所研究的(Al,Ga)Sb合金表现出极高的原子级均匀性。
英文摘要
Cross-sectional scanning tunneling microscopy at 5 K is used to investigate cation mixing in (Al,Ga)Sb layers grown by molecular beam epitaxy, via direct atom counting at the (1-10) and (110) cleavage planes. Electronic contrast between Al and Ga surface cations enables statistical analysis of the metal sublattice along the non-equivalent <110> directions within the zincblende (001) surface and along the [001] growth direction. The cation distribution is found to be random both along the growth direction and within the growth plane, with no evidence of long-range order or anisotropic growth kinetics; notably, the mean numbers of consecutive cations of the same type along the two in-plane directions are equal, possibly due to statistical averaging over randomly distributed subsurface cations. The results are compatible with either strain-mediated interactions during cation incorporation at the growth front or ideal, uncorrelated cation mixing. Overall, the examined (Al,Ga)Sb alloy shows an exceptionally high degree of atomic-level homogeneity.
