Density-functional study of hydrogen chemisorption on vicinal Si(001) surfaces

Article

关键词: SCANNING TUNNELING MICROSCOPY;    SI(100) SURFACES;    H-2 DESORPTION;    DETAILED BALANCE;    PHASE-DIAGRAM;    ADSORPTION;    SI;    STEPS;    DIFFUSION;    GROWTH;   

DOI  :  10.1103/PhysRevB.59.2790

来源: SCIE

【 摘 要 】

Relaxed atomic geometries and chemisorption energies have been calculated for the dissociative adsorption of molecular hydrogen on vicinal Si(001) surfaces. We employ density-functional theory, together with a pseudopotential for Si, and apply the generalized gradient approximation by Perdew and Wang to the exchange-correlation functional. We find the double-atomic-height rebonded D-B step, which is known to be stable on the clean surface, to remain stable on partially hydrogen-covered surfaces. The H atoms preferentially bind to the Si atoms at the rebonded step edge, with a chemisorption energy difference with respect to the terrace sites >0.1 eV. A surface with rebonded single atomic height S-A and S-B steps gives very similar results. The interaction between H-Si-Si-H monohydride units is shown to be unimportant for the calculation of the step-edge hydrogen occupation. Our results confirm the interpretation and results of the recent H-2 adsorption experiments on vicinal Si surfaces by Raschke and Hofer described in the preceding paper. [S0163-1829(99)13303-4].

【 授权许可】

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