Use ofL1L2,3VAuger transitions for an electronic-structure study of the A1—Si(111)-(2×1) interface

A1 and Si $L_1{L}_{2,3}V$ Auger transitions are used as a local probe for an A1—Si(111)-(2×1) interface electronic structure. Two interface state structures, which are Al $3s$- and Si $3s$-like in character, are newly observed in addition to the Al $3p$-Si $3p$ interface states at the Fermi level. The present results provide further support for the on-top-site chemisorption which was proposed for this A1—Si(111)-(2×1) interface, based on previous electron spectroscopic experiments.