Fluorinated Aminoalkoxide and Ketoiminate Indium Complexes as MOCVD Precursors for In 2 O 3 Thin Film Deposition Tsung-Yi Chou, Yun Chi,* Shu-Fen Huang, and Chao-Shiuan Liu Department of Chemistry, National Tsing Hua UniVersity, Hsinchu 30013, Taiwan, Republic of China Arthur J. Carty,* Ludmila Scoles, and Konstantin A. Udachin Steacie Institute for Molecular Sciences, National Research Council Canada, 100 Sussex DriVe, Ottawa, Ontario K1A 0R6, Canada Received May 29, 2003 The syntheses of two distinctive types of indium complex derived from trimethylindium (InMe 3 ) are reported. The first kind has a generalized structural formula [InMe 2 (amak)] 2 , where (amak)H is an abbreviation for a series of chelating amino alcohol ligands HOC(CF 3 ) 2 CH 2 NHR, R ) (CH 2 ) 2 OMe (1), Me (2), and Bu t (3), as well as HOC- (CF 3 ) 2 CH 2 NMe 2 (4); while the second type of complex is illustrated by [InMe 2 (keim)] (5), for which (keim)H is a tridentate ketoimine ligand of structural formula OdC(CF 3 )CH 2 C(CF 3 )dNCH 2 CH 2 NMe 2 . The solid-state structures of 2 and 5 were determined using single crystal X-ray diffraction studies. For the aminoalkoxide complexes 2-4, the existence of dimeric In 2 O 2 core structures in the solid state has been established with the amino fragment located trans to the alkoxide ligands, in a molecular arrangement which is in contrast to the distorted, trigonal bipyramidal geometry observed for the ketoiminate complex 5. Moreover, VT NMR studies of 2 revealed a rapid dimer-to-monomer equilibration and simultaneous rupture of the NfIn dative interaction, affording two interconvertible isomers related by having the N-Me substituents in either trans or cis dispositions. For complexes 2 and 5, deposition of In 2 O 3 thin films was successfully conducted at temperatures 400-500 °C, using O 2 as the carrier gas to induce indium oxide deposition and to suppress carbon impurity present in the thin film. Scanning electron micrographs (SEMs) revealed the surface morphologies. The atomic composition of these films was examined by both X-ray photoelectron spectroscopy (XPS) and Rutherford backscattering (RBS) methods, while X-ray diffraction studies (XRD) confirmed the formation of a preferred orientation along the (222) planes. In recent years, there has been increasing interest in the synthesis of new organoindium compounds because of their potential use as CVD precursors for the production of III-V and III-VI composite semiconductors. 1 Pioneering work was carried out by Cowley and Jones, 2 who synthesized com- plexes of general formula (L n InEL′ n ) x , featuring the desired 1:1 stoichiometry between the indium atom and the group V elements E, E ) N, P, or As. In these compounds, the ligands L and L′ can undergo facile dissociation upon thermal decomposition affording as deposited thin film materials with a 1:1 ratio of indium to pnictide element E. Through these and related studies, the concept of so-called single molecule precursors was developed. 3 Subsequently, CVD techniques using these source complexes have been greatly extended * Authors to whom correspondence should be addressed. E-mail: ychi@mx.nthu.edu.tw (Y.C.). Fax: (886) 3 572-0864 (Y.C.); arthur.carty@ nrc-cnrc.gc.ca (A.J.C.). Fax: (613) 957-8850. (1) (a) Fischer, R. A.; Sussek, H.; Miehr, A.; Pritzkow, H.; Herdtweck, E. J. Organomet. Chem. 1997, 548, 73. (b) Neumayer, D. A.; Cowley, A. H.; Decken, A.; Jones, R. A.; Lakhotia, V.; Ekerdt, J. G. J. Am. Chem. Soc. 1995, 117, 5893. (c) Kim, J.; Bott, S. G.; Hoffman, D. M. J. Chem. Soc., Dalton Trans. 1999, 141. (d) Suh, S.; Hoffman, D. M. J. Am. Chem. Soc. 2000, 122, 9396. (e) Lobinger, P.; Park, H. S.; Hohmeister, H.; Roesky, H. W. Chem. Vap. Deposition 2001, 7, 105. (2) (a) Cowley, A. H.; Jones, R. A. Angew. Chem., Int. Ed. Engl. 1989, 28, 1208. (b) Atwood, D. A.; Jones, R. A.; Cowley, A. H.; Bott, S. G.; Atwood, J. L. J. Organomet. Chem. 1992, 434, 143. (3) (a) Cowley, A. H.; Jones, R. A. Polyhedron 1994, 13, 1149. (b) Fischer, R. A.; Miehr, A.; Ambacher, O.; Metzger, T.; Born, E. J. Cryst. Growth 1997, 170, 139. (c) Colombo, D. G.; Gilmer, D. C.; Young, V. G. J.; Campbell, S. A.; Gladfelter, W. L. AdV. Mater. 1998, 10, 220. (d) Horley, G. A.; O’Brien, P.; Park, J.-H.; White, A. J. P.; Williams, D. J. J. Mater. Chem. 1999, 9, 1289. Inorg. Chem. 2003, 42, 6041-6049 10.1021/ic034588x CCC: $25.00 © 2003 American Chemical Society Inorganic Chemistry, Vol. 42, No. 19, 2003 6041 Published on Web 08/28/2003