Exploring the Dual Characteristics of CH3OH Adsorption to Metal Atomic Structures on Si (111)-7 × 7 Surface

Abstract

Metal atoms were deposited on an Si (111)-7 × 7 surface, and they were adsorbed with alcohol gases (CH3OH/C2H5OH/C3H7OH). Initially, CnH2n+1OH adsorption was simply used as an intermediate layer to prevent the chemical reaction between metal and Si atoms. Through scanning tunneling microscopy (STM) and a mass spectrometer, the CnH2n+1OH dissociation process is further derived as the construction of a surface quasi-potential with horizontal and vertical directions. With the help of three typical metal depositions, the surface characteristics of CH3OH adsorption are more clearly presented in this paper. Adjusting the preheating temperature, the difference of thermal stability between CH3O– and H+ could be obviously derived in Au deposition. After a large amount of H+ was separated, the isolation characteristic of CH3O– was discussed in the case of Fe deposition. In the process of building a new metal-CH3O–-H+ model, the dual characteristics of CH3OH were synthetically verified in Sn deposition. CH3O– adsorption is prone to influencing the interaction between the metal deposition and substrate surface in the vertical direction, while H+ adsorption determines the horizontal behavior of metal atoms. These investigations lead one to believe that, to a certain extent, the formation of regular metal atomic structures on the Si (111)-7 × 7-CH3OH surface is promoted, especially according to the dual characteristics and adsorption models we explored.

Surface Atomic Arrangement of Aluminum Ultra-Thin Layers Grown on Si(111)

“…Figure 2 a shows the RHEED pattern of the Al films grown on the Si(111)-7 × 7 surface. The image was captured in the [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ] azimuth direction after 2 h of annealing. The specular beam intensity indicated by spots A and B identifies the Si(111)-1 × 1 lattice originating from the bulk.…”

“…Knowing the details of the surface structure and its crystalline arrangement is critical for the deposition of ultrathin metallic films, especially if protection against atmospheric oxidation is required. The metallic surface is harmed by atmospheric exposure, which causes partial amorphization and severely limits its functionality [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. This affects surface electrical conductivity and controls the current efficiency in many applications [ 12 , 13 , 14 ].…”