MONITORING QUANTUM DOT GROWTH BY IN-SITU CANTILEVER SYSTEMS
Many theoretical and experimental investigations have been conducted to understand the growth mechanisms of quantum dots (QDs),in the hope that such understanding will allow better control of their electronic properties1,2.Without an in-situ measurement technique that monitors the growth modes (e.g.,the Frank-van der Merwe (FM),the Volmer-Weber (VW),the Stranski-Krastanow (SK)growth modes,and their corresponding ripening states) during deposition,it is very difficult to make conclusions on the growth mechanisms and on the ripening mechanisms of QDs.To monitor the growth modes,QDs are fabricated in a MBE chamber equipped with an in-situ cantilever measurement setup,and this cantilever is used as a substrate of QD growth3.In this paper,based on continuum models,we investigate a series of problems related to the strained heteroepitaxial in-situ cantilever systems of QD growth.Wefirst obtain the phase diagram,which provides a detailed characterization of the possible growth modes (FM,VW,SK and their corresponding ripening states) in terms of island density,surface energy,wetting layer thickness and cantilever thickness,etc.In this way,we can determine the growth mode according to the curvature of the cantilever.Then,in terms of the SK growth,we give the conditions that the equilibrium and stable QDs form.This provides the theoretical basis to control the locations,sizes and the shapes of QDs.Finally,we simulate the morphological evolution of SK system with in-situ cantilever.
H.L.Duan Y.Wang X.Yi
Institute of Nanotechnology,Forschungszentrum Karidsruhe,Postbox 3640,Karlsruhe,76021,Germany Colleg College of Engineering,Peking University,Beijing 100871,P.R.China
国际会议
第二届国际非均质材料力学会议(The Second International Conference on Heterogeneous Material Mechanics)
安徽黄山
英文
11
2008-06-03（万方平台首次上网日期，不代表论文的发表时间）