A damage-free and low-temperature neutral beam oxidation (NBO) process is used to directly form a thin germanium dioxide (GeO2) film. A GeO2 film with only a small amount of suboxide is formed even at a low substrate temperature of 300 °C because of the extremely low-activation-energy oxidation owing to bombardment with 5-eV-energy oxygen neutral beams. We combined the NBO process with hydrogen radical native oxide removal treatment to form high-quality GeO2 films, and our fabricated Al2O3/GeO2/Ge gate stack has an extremely low interface state density (Dit) of less than 1 × 1011 cm-2 eV-1.
ASJC Scopus subject areas
- Physics and Astronomy(all)