화학공학소재연구정보센터
Inorganic Chemistry, Vol.50, No.23, 12053-12063, 2011
Synthesis, Characterization, and Materials Chemistry of Group 4 Silylimides
This paper focuses on the development of potential single source precursors for M-N-Si (M = Ti, Zr or Hf) thin films. The titanium, zirconium, and hafnium silylimides (Me2N)(2)(MNSiRRR3)-R-1-R-2 [R-1 = R-2 = R-3 = Ph, M = Ti(1), Zr (2), Hf (3); R-1 = R-2 = R-3 = Et, M = Ti (4), Zr (5), Hf (6); R-1 = R-2 = Me, R-3 = Bu-t, M = Ti (7), Zr (8), Hf (9); R-1 = R-2 = R-3 = NMe2, M = Ti (10), Zr (11), Hf (12)] have been synthesized by the reaction of M(NMe2)(4) and (RRRSiNH2)-R-3-R-2-Si-1. All compounds are notably sensitive to air and moisture. Compounds 1, 2, 4, and 7-10 have been structurally characterized, and all are dimeric, with the general formula [M(NMe2)(2)(mu-NSiR3)](2), in which the mu(2)-NSiR3 groups bridges two four-coordinate metal centers. The hafnium compound 3 possesses the same basic dimeric structure but shows additional incorporation of liberated HNMe2 bonded to one metal. Compounds 11 and 12 are also both dimeric but also incorporate additional mu(2)-NMe2 groups, which bridge Si and either Zr or Hf metal centers in the solid state. The Zr and Hf metal centers are both five-coordinated in these species. Aerosol-assisted CVD (AA-CVD) using 4-7 and 9-12 as precursors generates amorphous films containing M, N, Si, C, and O; the films are dominated by MO2 with smaller contributions from MN, MC and MSiON based on XPS binding energies.