Study Of The Mn_xGe_1-xQuantum Dots Grown By Ion Beam Sputtering

The dilute magnetic semiconductor?DMS?can have both the charge and the spin,so that many disciplines can be combined.The DMS prepared by doping the magnetic element into column?element is compatible with Si substrate.The device prepared by DMS has the advantages of low power consumption,small size,non-volatile,high speed,etc.The research has been hot because theory study has found that the Curie temperature of this kind of DMS can achieve room temperature.All samples were prepared by Ion beam sputtering?IBSD?equipment.The article is to study the effect of growth temperature,deposition amount and the Mn doping concentration on the morphology,crystallization and magnetism of Mn_xGe_1-x quantum dots?QDs?.The results are as following:1.The importance of growth temperature,deposition amount and annealing temperature on the morphology of Mn_xGe_1-x QDs was studied by orthogonal experiment.It can be seen from the experimental results that the main influence is the growth temperature,followed by the deposition amount of Mn_xGe_1-x layer,and the weakest influence is the annealing temperature.According to the results of orthogonal experiment,the effects of growth temperature and deposition amount on the morphology of samples were studied,respectively.Experimental results show that as temperature increasing,the density of the samples increased and decreased after first increase,the size of QDs increased,and the crystallinity of Ge improved.In addition,the density of QDs also increased and then decreased with the increase of deposition amount,and the quantum dot size increased with the deposition amount increasing,and crystalline of Ge increased with the deposition amount of Mn Ge layer increasing.According to the above experimental results,the best growth temperature is 750?and the best Mn Ge layer deposition amount is 7 nm.2.The article also studies the effect of Mn doping concentration on the morphology,and crystallinity and magnetism of Mn_xGe_1-x QDs.Four Mn doping concentrations?0%,3.6%,4.8%and 5.5%?were obtained by co-sputtering,and multiple groups of samples were grown under different Mn doping concentrations.The experimental results show that with the increase of Mn doping concentration,the density decreased and the size of QDs increased.and the QDs advanced into the mature stage with the Mn doped in.The crystallinity of Ge improved when the Mn concentration increased.Moreover,with the increase of Mn doping,the Curie temperature of the sample increased.