Single-crystal Al growth on Si(111) by low-temperature molecular beam epitaxy

Abstract

Al films were formed by low temperature molecular beam epitaxy on Si(111) surfaces. The substrates were pretreated in a NH4F solution to obtain a nearly atomically flat surface by anisotropic etching. Planview transmission electron microscopy observation demonstrates that single-crystal Al films are successfully grown on the 7×7 surface structure. Such single-crystal growth is arrested on a disordered or hydrogen-terminated surface.