Dry Etching of HfO2 Films by Inductively Coupled Plasma

초록

Not only deposition of high quality high-k dielectric layer but its dry etching is very important for fabrication of complete gate stack structure. In this study, 2000?thick HfO2 films are deposited on Si wafers for etching experiments by reactive sputtering and annealed in oxygen. Dry etching of HfO2 is investigated in Cl2, SF6, HCl or Ar based ICP plasma. Etching characteristics are investigated in terms of RF powers, chamber pressures and gas compositions. It is found that physical sputtering effect enhances the formation of volatile hafnium halides. Single etching recipe is successfully used to pattern multiple layers of Pt/HfO2/Si structure.