Nano-Mechanical Studies of HfOx Thin Film for Oxygen Outgasing Effect during the Annealing Process

Abstract

The HfO X thin film was deposited what it has been paid attention to the next generation oxide thin layer of MOSFET (metal-Oxide semiconductor field-effect-transistor) by rf magnetron sputter on Si (100) substrate. The HfOx thin film was deposited using a various oxygen gas flows (5, 10, 15 sccm). After deposition, HfO X thin films were annealed from 400 to 800 o C for 20 min in nitrogen ambient. The electrical characteristics of the HfO X thin film was improved by leakage current properties, depending on the increase of oxygen gas flow and annealing temperature. In particular, the properties of nano-mechanics of HfO X thin films were measured by AFM and Nano-indenter. From the results, the maximum indentation depth at the basis of maximum indentation force was increased from 24.9 to 38.8 nm according to increase the annealing temperature. Especially, the indentation depth was increased rapidly at 800 o C. The rapid increasement of indentation depth was expected to be due to the change of residual stress in the HfO X thin film, and this result was caused by relative flux of oxygen outgasing during the annealing process.