Adsorption and growth of Al on Si(100) in the initial stage

The adsorption structures and growth of Al on Si(100) have been intensively studied using scanning tunneling microscope (STM). The high-resolution STM images are presented to demonstrate that the Al-adsorbed Si(100) surface i s accurately described by the parallel-dimer model, The structures at the e nds of Al dimer rows are further discussed by means of the illustration of STM images taken from the occupied and unoccupied electronic state surfaces . The dimer termination is confirmed to be a stable structure at the end of an Al dimer row. Moreover, the growth behavior of Al on the Si(100) surfac e with coverages over 0.5 monolayer (ML) are also investigated on the basis of STM observations as a function of the Al coverage up to 1.4 ML. The STM images reveal that once a well-ordered Al 2 x 2 adlayer is formed at 0.5 M L, further deposition of Al results in the disappearance of the Al 2 x 2 ph ase without disruption of the Si 2 x 1 reconstruction.