The effects of Ca atoms adsorbed on the C-incorporated Si(001)-4°-off substrate have been investigated by using scanning tunneling microscopy (STM) and synchrotron photoemission spectroscopy (PES). The C atoms incorporated into the subsurface by C 2 H 2 exposure and postannealing at 630 °C induce the c (4 × 4) structure and debunch the double-layer D B steps. The Ca atoms additionally adsorbed on this C-incorporated substrate induce terraces with a width twice that of the clean surface. Until postannealing up to 680 °C, no SiC trace is detected. The SiC islands start to be detected after postannealing at 780 °C, which is about 100 °C higher than that for the identical surface without Ca atoms. After the adsorbed Ca atoms are mostly desorbed by 880 °C postannealing, the SiC islands only remain on the surface. Such a result implies that the adsorbed Ca atoms act as a stabilizer to the subsurface C atoms and increase the onset temperature of SiC formation by 100 °C.

中文翻译：

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在掺碳的 Si(001)-4°-off 衬底上由 Ca 诱导的亚表面 C 的稳定性增加

已经通过使用扫描隧道显微镜 (STM) 和同步辐射光电子能谱 (PES) 研究了吸附在掺入碳的 Si(001)-4°-off 衬底上的 Ca 原子的影响。通过 C 2 H 2 暴露和 630 °C 后退火结合到次表面的 C 原子诱导 c (4 × 4) 结构并消除双层 DB 步骤。额外吸附在该掺碳基板上的 Ca 原子会产生宽度为清洁表面两倍的阶地。在高达 680 °C 的后退火之前，未检测到 SiC 痕迹。在 780°C 后退火后开始检测到 SiC 岛，这比没有 Ca 原子的相同表面高约 100°C。吸附的 Ca 原子在 880 °C 后退火后大部分解吸后，SiC 岛仅保留在表面。