Al and Ge simultaneous oxidation using neutral beam post-oxidation for formation of gate stack structures

Abstract

To obtain a high-quality Germanium (Ge) metal–oxide–semiconductor structure, a Ge gate stacked structure was fabricated using neutral beam post-oxidation. After deposition of a 1-nm-thick Al metal film on a Ge substrate, simultaneous oxidation of Al and Ge was carried out at 300 °C, and a Ge oxide film with 29% GeO2 content was obtained by controlling the acceleration bias power of the neutral oxygen beam. In addition, the fabricated AlOx/GeOx/Ge structure achieved a low interface state density of less than 1 × 1011 cm−2 eV−1 near the midgap.