Formation of In-(2×1) and In islands on Si(100)-(2×1) by femtosecond pulsed laser deposition

Abstract

The growth of indium on a vicinal Si(100)-(2×1) surface at room temperature by femtosecond pulsed laser deposition (fsPLD) was investigated by in situ reflection high-energy electron diffraction (RHEED). Recovery of the RHEED intensity was observed between laser pulses and when the growth was terminated. The surface diffusion coefficient of deposited In on initial two-dimensional (2D) In-(2×1) layer was determined. As growth proceeds, three-dimensional In islands grew on the 2D In-(2×1) layer. The RHEED specular profile was analyzed during film growth, while the grown In islands were examined by ex situ atomic force microscopy. The full width at half maximum of the specular peak decreased during the deposition, indicative of well-ordered growth and an increase of the island size. The In islands developed into elongated-polyhedral, circular, and triangular shapes. The elongated and triangular islands were highly oriented, parallel and perpendicular to the surface terrace edges, while the circular islands show a top flat surface. Deposition of In on Si(100)-(2×1) by fsPLD influenced the formation of the initial In-(2×1) layer and the morphology of the grown islands.