Synthesis and characterisation of Hf(thd)(2)X-2 derivatives [X = N(SiMe3)(2), OSiMe3 and (OSiBuMe2)-Bu-t] as precursors for MOCVD of hafnium silicate films

摘要

Hafnium beta-diketonatochlorides HfCl2(thd)(2) (1), HfCl(thd)(3) (2) as well as beta-diketonato-silylamide and/or siloxide derivatives of 1 namely Hf(thd)(2)[N(SiMe3)(2)](2) (3), Hf(thd)(2)(OSiMe3)(2) (4) and Hf(thd)(2)(OSi'BuMe2)(2) (5) (thd = 2,2,6,6-tetramethyl-3,5-heptanedionate) were synthesized and characterized by elemental analysis, FT-IR, H-1 NMR and TGA. 2 and 5 were also characterized by single-crystal X-ray diffraction. The siloxide ligands are in cis position for 5 and exert a strong trans effect. The new volatile compounds were tested as single-source precursors for the deposition of HfSixOy films by pulsed liquid injection MOCVD on Si(I 00) and R plane sapphire. The as-deposited at 600-800 degrees C films were essentially amorphous, Hf-rich (Hf/Hf + Si = 0.7-0.85) and smooth. (c) 2005 Elsevier Ltd. All rights reserved.