【摘要】 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6×1010cm-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.更多还原

【Abstract】 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 6×1010cm-2.The surface morphology evolution is investigated by AFM.更多还原