量子点的形成对Si/Ge界面互扩散的影响

Interface Interdiffusion Intensified by Formation of Quantum Dots

在Si(10 0 )衬底上低温生长了一层完全应变的Ge层 ,高温退火形成量子点 .我们用喇曼光谱研究了量子点形成时Si/Ge界面的互扩散现象 ,实验表明量子点的形成伴随着Si/Ge原子之间的互扩散 ,通常在Si衬底上形成的是SiGe合金量子点 ,而不是纯Ge量子点 .

Ge quantum dots(QDs) are fabricated by annealing the smooth strained Ge layers at the temperature of 600℃ in an ultrahigh vacuum,which are epitaxially grown at a low temperature of 400℃ on Si(100) substrate.Atomic interface interdiffusion during the formation of Ge QDs between Ge epilayer and Si substrate is investigated by Raman spectroscopy.Results indicate that the formation of Ge quantum dots is accompanied by the interface interdiffusion.Usually the quantum dots fabricated on Si substrate are not 'pure' Ge QDs,but Si/Ge alloy QDs.