Espalhamento de raios-X em ilhas auto-construídas de InAs

Abstract

In this work several structural and chemical properties of self-assembled InAs islands grown on GaAs(001) are studied using surface x-ray scattering with synchrotron radiation. The technique of x-ray diffraction under grazing incidence condition was employed to differentiate coherent and incoherent island in samples grown under different temperatures and with various coverages. We used a model of a strained pyramidal island to be able to interpret the x-ray results and correlate size and strainstate of these islands. The degree of GaAs interdiffusion in the islands was inferred from the variation of volume of the unit cell. The Poissons ratio of the two materials involved establishes a limit of tetragonal distortion for this material. Any variation in this distortion is associated with the presence of Ga inside the islands.