AlCl3-Dosed Si(100)-2 × 1: Adsorbates, Chlorinated Al Chains, and Incorporated Al
AlCl3-Dosed Si(100)-2 × 1: Adsorbates, Chlorinated Al Chains, and Incorporated Al
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DOI：
10.1021/acs.jpcc.1c00691
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发表时间：
2021-01
期刊：
影响因子：
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通讯作者：
M. Radue;S. Baek;Azadeh Farzaneh;K. Dwyer;Q. Campbell;A. Baczewski;E. Bussmann;George T. Wang;Yifei Mo;S. Misra;R. Butera
中科院分区：
文献类型：
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作者：
M. Radue;S. Baek;Azadeh Farzaneh;K. Dwyer;Q. Campbell;A. Baczewski;E. Bussmann;George T. Wang;Yifei Mo;S. Misra;R. Butera
研究了 AlCl$_{3}$ 在 Si(100) 上的吸附以及 AlCl$_{3}$ 掺杂衬底的退火效果，以揭示原子精度受体掺杂技术开发的关键表面过程。这项研究是通过扫描隧道显微镜 (STM)、X 射线光电子能谱 (XPS) 和密度泛函理论 (DFT) 计算进行的。在室温下，AlCl$_{3}$ 很容易吸附到 Si 基底二聚体上并解离形成多种物质。在低于 450 $^{\circ}$C 的温度下对 AlCl$_{3}$ 剂量的基底进行退火，产生了沿 Si(100) 二聚体行方向伸长的独特氯化铝链 (CAC)。提出了支持 DFT 计算的链原子模型。在 450 ℃及以上的温度下退火时，Al 被掺入到 Si 衬底中，并且在超过 450 ℃ 的温度下观察到 Cl 解吸。掺铝样品被封装在 Si 中，并通过二次离子质谱 (SIMS) 深度分析来量化 Al 原子浓度，结果发现在 $\sim$2.7 nm 厚的 $\delta$ 掺杂区域中 Al 原子浓度超过 10$^{20}$ cm$^{-3}$。这里达到的 Al 浓度和所使用的工艺参数促进 AlCl$_{3}$ 作为用于量子计算的新型受主掺杂 Si 材料和器件的可行气态前驱体。
The adsorption of AlCl$_{3}$ on Si(100) and the effect of annealing the AlCl$_{3}$-dosed substrate was studied to reveal key surface processes for the development of atomic-precision acceptor-doping techniques. This investigation was performed via scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations. At room temperature, AlCl$_{3}$ readily adsorbed to the Si substrate dimers and dissociated to form a variety of species. Annealing of the AlCl$_{3}$-dosed substrate at temperatures below 450 $^{\circ}$C produced unique chlorinated aluminum chains (CACs) elongated along the Si(100) dimer row direction. An atomic model for the chains is proposed with supporting DFT calculations. Al was incorporated into the Si substrate upon annealing at 450 $^{\circ}$C and above, and Cl desorption was observed for temperatures beyond 450 $^{\circ}$C. Al-incorporated samples were encapsulated in Si and characterized by secondary ion mass spectrometry (SIMS) depth profiling to quantify the Al atom concentration, which was found to be in excess of 10$^{20}$ cm$^{-3}$ across a $\sim$2.7 nm thick $\delta$-doped region. The Al concentration achieved here and the processing parameters utilized promote AlCl$_{3}$ as a viable gaseous precursor for novel acceptor-doped Si materials and devices for quantum computing.