Characterization of Hafnium Oxide Thin Films by Source Gas Pulse Introduced Metalorganic Chemical Vapor Deposition Using Amino-Family Hf Precursors

Abstract

We have characterized hafnium oxide thin films grown on SiO2/p-Si(001) by source gas pulse introduced metalorganic chemical vapor deposition (MOCVD) using tetrakis-diethylamido-hafnium (Hf[N(C2H5)2]4) and tetrakis-dimethylamido-hafnium (Hf[N(CH3)2]4). O2 or H2O is used as oxidant gas. It is demonstrated that the use of H2O can reduce the residual impurity concentrations of hafnium oxide films when the deposition temperature is as low as 280°C. In addition, we have found that the residual impurity concentration of hafnium oxide films grown with Hf[N(C2H5)2]4 is lower than that grown with Hf[N(CH3)2]4. This tendency agrees with the leakage current density. An equivalent SiO2 thickness (EOT) of 1.4 nm with 4.7×10-6 A/cm2 @-1 V have been obtained for the hafnium oxide films grown with Hf[N(C2H5)2]4 at 280°C.