Theoretical Study of Adsorption of Group IIIA Nitrides on Si(111)

Abstract

Adsorption of group IIIA nitrides (MN, M = B, Al, Ga, and In) on a model Si(111) surface has been studied by density functional theory calculations. Eight stable structures were determined for the MN adsorbed species. Their lowest energy structures are those with the adsorbate forming a bridge between the Si adatom and the Si rest atom as well as open structures with the M−N molecule attached to a Si adatom or a Si rest atom via N. The energy ordering of these stable structures varies according to the particular metal atom. The binding energy, including the basis set superposition error, of the lowest calculated minimum MN−Si(111) structure for the different metals M ranges from 5.1 to 6.0 eV.

SiO Desorption Kinetics of Si(111) Surface Oxidation Studied by Real-Time Photoelectron Spectroscopy

“…However, the high oxidation state Si 3+ increased rapidly together with the slight increases in Si 2+ and Si 4+ , and a decrease in Si 1+ at θ oxide ∼ 50%. Considering the possible oxygen adsorption species proposed in the previous work [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24], we suggest that the oxygen adsorption species ins×3, ad-ins×2, and tri-ins×2, schematically illustrated in Figs. 7(a), (b) and (c), respectively, with the oxidation state Si 3+ was formed at θ oxide ∼ 50% and rendered the SiO desorption less favorable owing to the high energetic stability.…”

“…The DFT calculations were performed using the hybrid functional B3LYP [13,14] and 6-31G(d) basis set [15,16] using Gaussian 09. In the present work, the adsorption energies of various oxygen adsorption species on Si(111)7×7 were determined by means of a Si 27 H 24 cluster model, in which hydrogen atoms terminated the 27-Si atom cluster except for the adatom and the rest atom [17,18].…”

Theoretical Study of Adsorption and Diffusion of Group IIIA Metals on Si(111)

“…DFT calculations were carried out using the B3LYP functional , and the DGDZVP basis set (double-ζ valence plus polarization, i.e., [3s2p1d B, N /4s3p1d Al, Si /5s4p2d Ga /6s5p3d In ]) . This combination was considered to be the best choice for the present calculations, since the B3LYP/DGDZVP calculations on the diatomic molecules MN and MSi present satisfactory similarity with the best known ab initio calculations and experiments . Moreover, the large size (49 atoms) of the systems calculated practically forbids the use of MRCI (multireference configuration interaction) or CC (coupled cluster) methods.…”

“…Cluster calculations have been used to determine the interaction of a single group IIIA metal atom M, M = B, Al, Ga, and In with the Si(111) surface. A 5-layer one-rest one-adatom (1R-1A) cluster model of Si(111) was constructed as previously detailed ,, using the dimer-adatom-stacking fault (DAS) structure and the LEED data of Tong et al for the Si(111)-7 × 7 reconstructed surface. Hydrogen atoms (white spheres) have been added to terminate the 26-Si atom cluster (gray spheres = Si) at the sides as well as below the lowest Si level, while the adatom and rest atom are left with one dangling bond (i.e., one unpaired electron) each.…”

“…In the present study, we report the results of a systematic investigation of the interaction of group IIIA metal atoms M, M = B, Al, Ga, and In, with the reconstructed Si(111) surface at very low coverage. Using the same methodology as in our previous studies − on the chemisorption of gallium (Ga, Ga + ) and group IIIA nitrides on Si(111), , the electronic and geometric structure and the bonding of chemisorbed M on Si(111) are investigated using density functional theory (DFT) calculations and a Si 26 H 22 model of the Si(111) surface. The diffusion of M in the Si(111) surface is studied and the energy barriers between different stable structures are reported.…”