Study of dependence of electron beam induced surface relief formation on Ge-As-Se thin films on the film elemental composition

Formation of surface reliefs induced by electron beam on surface of Ge-As-Se thin films is investigated as a function of concentration of elements in the films. It was found that during local electron irradiation at low doses in the range from 9.3-0.3 C·cm− 2 the electron beam induces the formation of cones with Gaussian profile on the surfaces of the films. At high doses in the range from 4.6-93.0 C·cm− 2 we observe formation of craters also with a smooth Gaussian profile. These two intervals are separated by a point where surface relief inversion occurs. We find that surface relief relaxation times are several milliseconds or few seconds for low dose and high dose intervals, respectively. The mechanism of formation of the relief is explained by formation of two-layer space charge region and electrostatic interactions within this region. We showed that maximal values of the surface relief parameters such as cone height and crater depth as well as the smallest dose at which inversion of surface profile from positive to negative occurs are connected with composition dependent mean coordination number at which the films also exhibit minimal electrical conductivity value.