斜切基片上溅射生长高密度小尺寸Ge纳米点的研究

Study of the small and dense Ge nanodots deposited on vicinal Si(001) substrate by ion-beam sputtering

采用离子束溅射技术,在斜切的单晶Si基底上生长了高密度的小尺寸Ge纳米点。系统研究了斜切基底上的表面台阶对Ge纳米点生长初期表面原子吸附行为的影响,以及斜切基片上Ge纳米点随原子沉积量的演变规律。实验结果表明,在斜切基片上原子级的表面台阶能有效地抑制吸附原子的表面扩散。因此,有利于Ge纳米点的形核,并抑制纳米点的过度长大,从而获得高密度、小尺寸的Ge纳米点。

Small self-assembled Ge nanodots were grown densely on vicinal Si （001） substrate by ion beam sput- tering （IBS） technique. The action of the adsorbed atoms on vicinal substrate was monitored during the initial growth. The topography of nanodot as well as the size and density was observed to evaluate with deposition amount. Results show that the diffusion of the adsorbed atoms is restricted by the step of the vicinal substrate, which promoted nucleation and suppressed the nanodots coarsening. Thus small size nanodots with high density are obtained on vicinal substrate.