Physics and technology of high-k gate dielectrics ii vol:2003 issue:22 pages:101-111
ELECTROCHEMICAL SOCIETY SERIES
2nd International Symposium on High Dielectrics Constant Materials Orlando, FL, OCT 12-16, 2003
The feasibility of deposition of HfOxNy and HfSixOyNz high-k layers using MOCVD in gas flows of N2O diluted with O-2 has been investigated. The properties of the high-k layers, such as chemical composition, thermal stability, leakage and k-value, have been studied with TOF-SIMS, high-temperature XRD, high-resolution TEM and Quantox. It is found that HfOxNy and HfSixOyNz can be deposited with MOCVD in the mixed gas flow. TOF-SIMS shows a significant nitrogen concentration in the HfOxNy layer grown in pure N2O. XRD shows that the phase composition and phase transformation behavior of the layers change as a function of the gas flow. Quantox measurement reveals that the layers grown in pure N2O are conductive, while the others have acceptable leakage. This is confirmed by C-V measurement of capacitors. k-value boost has been found in the samples grown in the mixed gas flows, as a function of N2O concentration.