Nonplanar and noncontinuous buried layers of SiO 2 in silicon formed by ion beam synthesis

Abstract

The synthesis of buried layers of SiO 2 by the implantation of high doses (1.8 × 10 18O + cm −2) of O + ions through thick oxide masks is described. Due to the rapid sputter erosion of the SiO 2 mask (1.1 atoms/particle) these layers grow, unlike conventional SIMOX structures, by the preferential growth (“internal oxidation”) of the lower SiO 2/Si interface. It is shown that improved TDI structures may be formed by implantation into a thick (1.8 μm) oxide mask.