Physical and electrical characterizations of ultrathin Si-rich Hf-silicate film and Hf-silicate/SiO2 bilayer deposited by atomic layer chemical vapor deposition

Abstract

Hf-silicate films and Hf-silicate/SiO2 bilayers were fabricated on Si(100) to study SiO2 buffer layer effects. Hf-silicate layers were grown by atomic layer chemical vapor deposition using alternate supply of tetrakis-diethylamido-hafnium (Hf[N(C2H5)(2)](4)) and tetra-n-butyl-orthosilicate [Si((OBu)-Bu-n)(4)] precursors. Ultrathin SiO2 buffer layers effectively suppressed Hf-rich phases and dislocations found at Hf-silicate/Si interfaces in Hf-silicate samples. These effects resulted in the significantly improved electrical properties of bilayers, compared to Hf-silicate films, such as low leakage current density (J(g)), low flatband voltage (V-fb) shift, and high breakdown voltage (V-BD). (c) 2006 American Institute of Physics.