Selective-area chemical-vapor deposition of Si using a bilayer dielectric mask patterned by proximal probe oxidation

Silicon nitride (Si₃N₄) is a very robust material against oxidation and is typically used as an oxidation mask. Here, we report atomic-force microscope (AFM)-based local oxidation of Si₃N₄ and its applications in selective-area epitaxial growth using chemical-vapor deposition. High growth selectivity is accomplished in this work by employing a SiO₂/Si₃N₄ bilayer mask structure, which is formed by locally oxidizing the Si₃N₄ surface (for defining the growth windows), depositing a blanket SiO₂ layer, and then selectively removing SiO₂ in the growth windows. High-resolution transmission electron microscopy images reveal that the selectively deposited Si structures can be grown with a high degree of crystalline perfection, while excellent size uniformity is confirmed by large-area AFM images. © 2001 American Vacuum Society.