Synthesis and characterisation of Hf(thd)2X2 derivatives [X = N(SiMe3)2, OSiMe3 and OSitBuMe2] as precursors for MOCVD of hafnium silicate films

Hafnium β-diketonatochlorides HfCl2(thd)2 (1), HfCl(thd)3 (2) as well as β-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(OSitBuMe2)2 (5) (thd = 2,2,6,6-tetramethyl-3,5-heptanedionate) were synthesized and characterized by elemental analysis, FT-IR, 1H 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(1 0 0) and R plane sapphire. The as-deposited at 600–800 °C films were essentially amorphous, Hf-rich (Hf/Hf + Si = 0.7–0.85) and smooth.

Volatile hafnium β-diketonato derivatives namely Hf(thd)2[N(SiMe3)2]2 (3), Hf(thd)2(OSiMe3)2 (4) and Hf(thd)2(OSitBuMe2)2 (5) (thd = 2,2,6,6-tetramethyl-3,5-heptanedionate) were synthesized and characterized by FT-IR, 1H NMR, TGA. and by single-crystal X-ray diffraction for Hf(thd)3Cl and 5. These compounds were tested as single-source precursors for the deposition of HfSixOy films by pulsed liquid injection MOCVD on Si(100) and R plane sapphire. The films were characterized by XRD and XPS. The as-deposited at 600–800 °C films were essentially amorphous, Hf-rich, smooth and quite pure with respect to carbon contaminationFigure optionsDownload as PowerPoint slide