Preparation And Study Of Morphology On InAlAs/GaAs(001) Rings And Dots Structure

In this paper,a mixed droplet epitaxy method is applied to prepare(In)Al As quantum rings and dots structures on a Ga As(001)substrate.The effects of indium composition and arsenic pressure on the structure of(In)Al As quantum rings and dots are mainly studied.In the early stage of the experiment,in order to find the common deposition temperature of In and Al droplets,this article directly studies the deposition of Al droplets with a low deposition amount,and finds the deposition temperature under the best uniformity condition of Al droplets as the common deposition temperature of In and Al droplets.Furthermore,the mixed droplet epitaxy was used to grow at this temperature,and the effects of In composition and As pressure on the structure of(In)Al As quantum rings and dots were studied.We have drawn the following conclusions:(1)The research on indium droplets and aluminum droplets found that the density of the droplets decreases with the increase of the substrate temperature,meanwhile,the average size of the droplets continues to increase.In addition,the deposition rate of the droplets also affects the increases density of the droplets.Therefore,one can change the density of the droplets by controlling the substrate temperature and the deposition rate of the droplets,so that the droplets are more uniformly distributed,the uniformity of the droplets is improved,and this provides a guidance for the uniformity of the subsequent growth of the(In)Al As quantum rings and dots structure.(2)The study of the indium composition on the(In)Al As quantum rings and dots structure has found that the density of the quantum structure gradually decreases with the increase of the indium composition;as the indium composition continues to increase,the diameter of the quantum dots or quantum rings increases continuously;the central hole of the quantum ring becomes deeper with the increase of the indium component,and the rate of change gradually increases,which is almost close to the exponential growth.(3)The study of arsenic pressure on the structure of(In)Al As quantum rings and dots shows that with the increase of arsenic pressure,the size of quantum dots or quantum rings becomes smaller due to the crystallization process which hinders the diffusion of indium and aluminum atoms;The central hole depth of the ring is deeper at low arsenic pressure than at high arsenic pressure.The above-mentioned related research results have important guiding significance for the growth of the(In)Al As quantum rings and dots structures by the mixed droplet epitaxy method,and it can provide a certain theoretical guidance for the experimental method of preparing the(In)Al As quantum rings and dots structure.