Low energy ion scattering study of adsorption and desorption processes of Pb on Si(111) surfaces

摘要: Abstract The initial growth process and the thermal desorption of Pb on Si(111) substrate have been studied in detail by LEED ISS (low-energy ion-scattering spectroscopy), where neon ions 500 eV were used as probe ions. a Si(111)7 follows Stranski-Krastanov mechanism, which is common to room temperature 340°C one. However, intermediate layer at are different from each other its structure formation process. Pb(111) whose orientation identical substrate, while that Si(111)1-Pb consisting 1 ML Pb. data suggest extremely small 2D (two-dimensional) islands formed mid-course coalesce into layer, 1-Pb starts form when density gas phase initially comes up critical value (which 0.27 340°C). When heat treatment made course deposition, Si (111) 3 - (α) probably consists 4 before 3D islands. can be divided two steps, namely, (1) leaving (β) behind (2) structure. kinetics first step zero-order, second has high order kinetics. It proposed atoms √3-Pb(β) bonded three atoms, such bonding configuration responsible for observed.