利用 Au/Sb 和 Au/Si 共晶点温度较低的特点,通过在~400 ℃ 合金化的方法,在硅片表面实现了掺 Sb 纳米晶体的制作。扫描电子显微镜观察到了 Au/Si 合金化反应形成的倒金字塔形蚀坑以及纳米结构的存在,拉曼散射光谱证实这些结构主要是纳米尺度的晶体,二次离子质谱表明 Sb 在 Si 中的掺杂浓度大于 2×1018 cm-3,超过了 Sb 在体晶硅中的固溶度。该纳米晶体的制作方法简单易行,热预算较低,和其他微纳器件制作工艺的兼容性较好。

Taking advantage of the eutectic points of Au/Sb and Au/Si at low temperatures,silicon nanocrystals doped with Sb atoms are fabricated on the surface of silicon wafers after an alloying reaction around 400 ℃.Scanning electron microscopy demonstrates that there exist craters in the shape of an inverted pyramid and large amount of nanostructures inside craters on the wafer surface due to Au/Si alloying reactions.Raman scattering spectroscopy verifies that these nanograins largely possess a crystal-like lattice structure.Secondary ion mass spectroscopy reveals that the doping concentration of Sb in Si exceeds 2×1018 cm-3,surpassing the solid solubility of Sb in the bulk silicon crystal.This growth method is easy to implement with a low thermal budget,which potentially provides it the good compatibility with other micro/nano fabrication processes.