Scaling study of molecular beam epitaxy grown InAs/Al2O3 films using atomic force microscopy

Abstract

Scaling study of polycrystalline InAs thin films grown by molecular beam epitaxy on c-plane sapphire (001) substrate has been presented using atomic force microscopy, corresponding height-height correlation function and two-dimensional fast Fourier transform profiles. Height-height correlation function profiles exhibit oscillations at larger lateral distances along with ring-like features in the respective two-dimensional fast Fourier transform scans and clearly indicate mound-like surface morphology. Scaling parameters, interface width and lateral correlation length were extracted and their dependence on the growth temperatures were investigated. The growth mechanism has been well explained in terms of diffusion effects and the obtained parameters qualitatively agrees with the parameters obtained for the growth of InAs films grown on Si(100) substrate under identical growth conditions. Our study suggests that molecular beam epitaxy grown InAs thin films on lattice mismatched substrates (c-plane sapphire(001) and Si(100) substrate) follows the same growth behavior under identical growth conditions.