Epitaxial growth, structure, and composition of Fe films on GaAs(001)‐2×4
Epitaxial growth, structure, and composition of Fe films on GaAs(001)‐2×4
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DOI：
10.1116/1.588806
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发表时间：
1996-07
影响因子：
1.4
通讯作者：
E. Kneedler;P. Thibado;B. Jonker;B. R. Bennett;B. V. Shanabrook;R. Wagner;L. Whitman
中科院分区：
文献类型：
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作者：
E. Kneedler;P. Thibado;B. Jonker;B. R. Bennett;B. V. Shanabrook;R. Wagner;L. Whitman
利用扫描隧道显微镜（STM）、光电子衍射（PED）和x射线光电子能谱（XPS）原位研究了175°C下生长在As端GaAs（001）‐2×4表面上的Fe膜的结构和组成。采用分子束外延（MBE）法制备了GaAs表面，并显示出大的有序的原子梯田。我们发现2×4重构对Fe的成核和生长有显著的影响，初始成核发生在As -二聚体位点。STM显示，前半层铁在生长到邻近的富镓行之前，沿着砷二聚体行形成小的二维岛屿，没有衬底破坏的证据。PED表明，第n层的生长锋面局限于第（n+1）层，以逐层生长为主。XPS谱图表明，Fe膜中存在Ga和As从界面向外扩散的浓度梯度，其中部分As向Fe表面偏析。
The structure and composition of Fe films grown on As‐terminated GaAs(001)‐2×4 surfaces at 175 °C has been studied in situ with scanning tunneling microscopy (STM), photoelectron diffraction (PED), and x‐ray photoelectron spectroscopy (XPS). The GaAs surfaces were prepared by molecular beam epitaxy (MBE) and exhibited large atomically well‐ordered terraces. We find that the 2×4 reconstruction has a significant impact on the Fe nucleation and growth, with initial nucleation occurring at As‐dimer sites. STM reveals that the first half‐monolayer of Fe forms small two‐dimensional islands along the As‐dimer rows before growing onto the adjacent Ga‐rich rows, with no evidence of substrate disruption. PED indicates that the growth is predominantly layer by layer, with the growth front for the nth deposited layer limited to the (n+1)th layer. XPS spectra show that the Fe films include a concentration gradient of Ga and As out‐diffused from the interface, with some of the As segregating to the Fe surface, similar ...