Decomposition behaviors of bis(N-alkoxy-p-ketoiminate) titanium complexes in the depositions of titanium oxide and barium strontium titanate films

Abstract Five bis( N -alkoxy-β-ketoiminate) titanium complexes [Ti(ONO-1) 2 : titanium bis(2- N -(2-hydroxyethylimino)-4-pentanoate), Ti(ONO-2) 2 : titanium bis(2- N -(2-hydroxy-2-methylethylimino)-4-pentanoate), Ti(ONO-3) 2 : titanium bis(2- N -(2-hydroxy-1-methylethylimino)-4-pentanoate), Ti(ONO-4) 2 : titanium bis(2- N -(1,1-dimethyl-2-hydroxyethylimino)-4-pentanoate), Ti(ONO-5) 2 : titanium bis(2,6-dimethyl-3- N -(2-hydroxy-2-methylethylimino)-5-heptanoate)] have been synthesized and tested as liquid delivery metal–organic chemical vapor deposition (MOCVD) precursors for titanium oxide (TiO 2 ) and barium strontium titanate (Ba x Sr 1− x TiO 3 , BST) thin films. It is indicated from thermogravimetric (TG) analyses that Ti(ONO-2) 2 and Ti(ONO-3) 2 leave negligible amount of residue after thermal decomposition. 1 H nuclear magnetic resonance (NMR) spectra and mass spectroscopic data imply that Ti(ONO-2) 2 is chemically stable during the flash evaporation at 280 °C. The deposition rate of TiO 2 film with Ti(ONO-2) 2 and Ti(ONO-3) 2 was comparable to that with Ti(mpd)(tmhd) 2 , and approximately three times that with Ti(tmhd) 2 (O- i Pr) 2 [mpd: 2-methyl-2,4-pentanedioxy, tmhd: 2,2,6,6,-tetramethyl-3,5-heptanedionate, O- i Pr: isopropoxy]. Ti(ONO-2) 2 was utilized for the deposition of a BST film with conventional Ba and Sr precursors, Ba(methd) 2 and Sr(methd) 2 (methd: methoxy–ethoxy–tetramethyl-heptanedionate), and the as-deposited BST films showed very low carbon content, and smooth surface morphology without any impurity phase.