Formation of Mn-germanide nanodots on ultrathin SiO₂induced by remote hydrogen plasma

Abstract

High-density Mn-germanide nanodots [Mn x Ge 1%x (x = 0.8) NDs] with an areal dot density as high as >10 12 cm %2 were formed on thermally grown SiO 2 by exposing >1.0-nm-thick Mn/>1.0-nm-thick amorphous Ge (a-Ge) bilayer stacked structures to a remote H 2 plasma (H 2 -RP) without external heating. The germanidation reaction of the Mn/a-Ge bilayer was observed through high resolution X-ray photoelectron spectroscopy measurements. Electrical isolation among the Mn x Ge 1%x (x = 0.8) NDs was verified from the changes in surface potential after charge injection using an atomic force microscope/Kelvin probe technique. As seen from the VHF input power and exposure time dependence of the ultrathin bilayer stacked structures, control of thickness and H-radical flux are important parameters for the high-density formation of MnGe alloy NDs induced by H 2 -RP.