Thermal stability and electrical characteristics of ultrathin hafnium oxide gate dielectric reoxidized with rapid thermal annealing

Dielectric properties of ultrathin hafnium oxide reoxidized with rapid thermal annealing (RTA) have been investigated. Capacitance equivalent oxide thickness (CET) of 45 Angstrom hafnium oxide was scaled down to similar to 10 A with a leakage current less than 3 x 10(-2) A/cm(2) at -1.5 V (i.e., similar to 2 V below V-FB). Leakage current increase due to crystallization was not observed even after 900 degrees C rapid thermal annealing (RTA), but CET did increase after high temperature RTA due to the interfacial layer growth and possible silicate formation in the HfO2 film. (C) 2000 American Institute of Physics. [S0003-6951(00)04414-4].