The impact of TiN deposition on thin HfO2 films formed on Si substrates was studied using x-ray photoelectron spectroscopy and a monoenergetic positron beam. For the predeposition sample, the positrons implanted into Si were found to diffuse toward the HfO2/Si interface under the influence of the electric field, suggesting the presence of negative charges in HfO2. After TiN was deposited by chemical vapor deposition, no large change in the defect species was observed. After TiN was deposited by physical vapor deposition, however, positive charges were introduced at the TiN/HfO2 interface, which were associated with the incorporation of nitride into HfO2 and/or the plasma damage at the surface of HfO2, and the resultant formation of positively charged oxygen vacancies.
ASJC Scopus subject areas
- Physics and Astronomy(all)