The Research Of Annealing On Crystallization Of Ge,Si Film And Sputtering Growth Of Ge QD On Graphene

In recent decades,Si and Ge,as a representative of group four semiconductor materials,have provided a preferred ones for a new style of solid state electronics or optoelectronic devices and its basic theory research,because of its special properties and potential applications in the field of material information,energy and environment.This paper is mainly engaged in the research of Ge,Si thin film materials and zero-dimensional materials.The crystallinity and the surface roughness of the film material have great influence on its physical properties.The rapid thermal annealing method is used to control the crystal structure of different types of thin film materials.Among them,the factors that have effects on the crystallinity of Ge films were discussed,such as annealing temperature,annealing time,quality and thickness of Si buffer layer.and the effects of annealing temperature and the quality of c-Ge landfill on the crystallinity of Si films were investigated.In addition,the influence of different growth times on Ge quantum dots deposited on the surface of graphene was investigated.The main results of the above studies are listed as follows:1.The main factors affecting the crystallinity of Ge films were analyzed by orthogonal test,and the order of the influencing factors was determined,namely:annealing temperature>annealing time>Si buffer layer thickness.The optimized parameters of each factor were annealing temperature of 450?(slightly better than 420?),annealing time of 20 min and 50 nm of Si buffer layer.Then,the effects of annealing temperature,annealing time and Si buffer layer thickness on the crystallinity of Ge films were investigated,respectively.At 420? annealing for 20 min,the crystallinity of Ge films is the highest,up to 80%,and the surface roughness is small,with 50 nm thick Si buffer layer.In general,the Ge film is of good quality.The results from three series of experiments are consistent with the conclusions of orthogonal experiment.2.The effect of the quality of Si buffer layer on the crystallinity of Ge film was studied.The annealing temperature of crystallization of the Ge film on the a-Si buffer layer is 420? and the crystallinity is up to 80%;The annealing temperature of the Ge film on the c-Si buffer layer for crystallization is 360?,reduced by 60?.Similarly,the crystallinity of the Ge film is reduced by about 15%.At the same time,it was found that there was no intermixing phenomenon of Ge and Si in Ge films annealed at low temperature(? 450?).3.The effects of annealing temperature and the quality of Ge inducing layer on the crystallinity of Si thin films were investigated.With the increase of annealing temperature,the crystallinity of Si film is better.Among them,the annealing temperature of 800?,the crystallinity of Si film on a-Ge inducing layer is only 40%.The crystallization of Si film,however,was induced by the crystallization of Ge inducing layer,and the crystallinity for Si film can be increased by 10%.4.When the growth temperature is 270?,the size and density of Ge quantum dots on graphene virtual substrate increase firstly and then decrease with the increase of the sputtering time.At the sputtering time of 180 s,the density of Ge quantum dots is the largest,and its morphology and size is the most uniform.The existence of Ge was confirmed by the quantitative analysis of XRF,and the graphene-based Ge QDs on was also confirmed.