Effect of As4 beam equivalent pressure on the growth dynamics of InAs films grown at low temperature on graphene layers

Abstract

The present study investigates the growth of InAs films at low temperature on graphene synthesized via molecular beam epitaxy, emphasizing the effect of As4 beam equivalent pressure (5.0 × 10⁻6 Torr (low) and 4.5 × 10⁻⁵ (high)) on the growth dynamics. X-ray diffraction, scanning electron microscopy, and atomic force microscopy, along with correlation functions, revealed that monitoring the As4 beam equivalent pressure affects the structural properties of polycrystalline InAs films grown on the graphene/Si layer. The film thickness (particle size) was found to be 172 ± 10 nm and 216 ± 10 nm (40 ± 2 nm and 42 ± 2 nm) for the InAs layers grown at low and high As4 beam equivalent pressure. The increase in the film thickness and particle size with increasing the As4 beam equivalent pressure is attributed to improved material availability and surface kinetics due to the large migration energy of As compared to In and hence the larger diffusion length of In. Conversely, decreasing As4 beam equivalent pressure raises the roughness scaling exponent and enlarges interface width (0.17 µm and 0.31 µm for films grown at high and low As4 beam equivalent pressure) and lateral correlation length, implying smoother surfaces due to larger particles. These insights are pivotal for fabricating advanced semiconductors, underscoring As4 beam equivalent pressure's role in optimizing InAs films for electronic and optoelectronic applications.