Patterned silicon molecular beam epitaxy with submicron lateral resolution

Abstract

Patterned epitaxial silicon films are grown on silicon substrates by molecular beam deposition (MBE) through an oxide masking layer. Epitaxial patterns faithfully reproduce the oxide mask, which is fabricated by conventional photolithographic processes. Resolution is determined solely by the mask, and linewidths below 1 μ are demonstrated. Sample morphology and crystallinity are examined by scanning and transmission electron microscopy, and Nomarski interference contrast microscopy in conjunction with chemical defect etching. These techniques confirm that patterned films are epitaxial and free of observable defects. A chemical liftoff step dissolves the oxide mask and leaves an elevated silicon pattern. Patterned film growth requires no modification to the MBE apparatus.