摘要
Ge self-assembled quantum dots （SAQDs） are grown with a self-assembled UHV/CVD epitaxy system. Then, the as-grown Ge quantum dots are annealed by ArF excimer laser. In the ultra-shot laser pulse duration, -20ns, bulk diffusion is forbidden,and only surface diffusion occurs, resulting in a laser induced quantum dot （LIQD）. The diameter of the LIQD is 20-25nm which is much smaller than the as-grown dot and the LIQD has a higher density of about 6 ×10^10cm^-2. The surface morphology evolution is investigated by AFM.
使用ArF准分子激光脉冲对UHV/CVD条件下生长的Ge量子点进行退火处理,获得了底宽为20-25nm的光致量子点（LIQD）,远小于退火前的量子点大小.LIQD的密度约为6×10^10cm^-2.分析表明,在ArF准分子激光脉冲作用下,退火样品只有表面扩散,并没有体扩散.激光脉冲对表面Ge原子的扩散控制导致了Ge量子点形貌发生了巨大的改变.该方法为获得高密度小尺寸的Ge量子点提供了新的途径.采用原子力显微镜对光致量子点的表面形貌进行了研究.
基金
国家自然科学基金(批准号:60336010)
国家重点基础研究发展规划(批准号:G2000036605)资助项目~~
