Reference

Guanidinate-Stabilized Monomeric Hafnium Amide Complexes as Promising Precursors for MOCVD of HfO2

All Rights Reserved. Guanidinate-Stabilized Monomeric Hafnium Amide Complexes as Promising Precursors for MOCVD of HfO2. Milanov, Andrian; Bhakta, Raghunandan; Baunemann, Arne; Becker, Hans-Werner; Thomas, Reji; Ehrhart, Peter; Winter, Manuela; Devi, Anjana (Inorganic Materials Chemistry Group, Lehrstuhl fuer Anorganische Chemie II, Ruhr-University Bochum, Bochum D-44780, Germany). Inorganic Chemistry, 45(26), 11008-11018 (English) 2006 American Chemical Society. CODEN: INOCAJ. ISSN: 0020-1669. DOCUMENT TYPE: Journal CA Section: 78 (Inorganic Chemicals and Reactions) Section cross-reference(s): 75, 76 Novel guanidinato complexes of hafnium [Hf{h2-(iPrN)2CNR2}2(NR2)2] (R2 = Et2, 1; Et, Me, 2; Me2, 3), synthesized by insertion reactions of N,N'-diisopropylcarbodiimide into the M-N bonds of homologous Hf amide complexes and {[m2-NC(NMe2)2][NC(NMe2)2]2HfCl}2 (4) using a salt metathesis reaction, are reported. Single-crystal x-ray diffraction anal. revealed that compds. 1-3 were monomers, while compd. 4 is a dimer. The obsd. fluxional behavior of compds. 1-3 was studied in detail using variable-temp. and two-dimensional NMR techniques. The thermal characteristics of compds. 1-3 seem promising for HfO2 thin films by vapor deposition techniques. Metal-org. CVD expts. with compd. 2 as the precursor resulted in smooth, uniform, and stoichiometric HfO2 thin films at relatively low deposition temps. The basic properties of HfO2 thin films were characterized.Except for chemicals metioned above, 352535-01-4 and 918408-77-2 are also used. .

Characterization of hafnium oxide thin films by source gas pulse introduced metalorganic chemical vapor deposition using amino-family Hf precursors

Characterization of hafnium oxide thin films by source gas pulse introduced metalorganic chemical vapor deposition using amino-family Hf precursors.Several substances are used for example 352535-01-4 and 19824-55-6 which are their cas registry numbers. Hino, Shiro; Nakayama, Makoto; Takahashi, Kenji; Funakubo, Hiroshi; Tokumitsu, Eisuke (Precision and Intelligence Laboratory, Tokyo Institute of Technology, Kanagawa 226-8503, Japan). Japanese Journal of Applied Physics, Part 1: Regular Papers, Short Notes & Review Papers, 42(9B), 6015-6018 (English) 2003 Japan Society of Applied Physics. CODEN: JAPNDE. DOCUMENT TYPE: Journal CA Section: 76 (Electric Phenomena) The authors have characterized hafnium oxide thin films grown on SiO2/p-Si(001) by source gas pulse introduced metalorg. chem. vapor deposition (MOCVD) using tetrakis-diethylamido-hafnium (Hf[N(C2H5)2]4) and tetrakis-dimethylamido-hafnium (Hf[N(CH3)2]4). O2 or H2O is used as oxidant gas. It is demonstrated that the use of H2O can reduce the residual impurity concns. of hafnium oxide films when the deposition temp. is as low as 280°. In addn., the authors have found that the residual impurity concn. of hafnium oxide films grown with Hf[N(C2H5)2]4 is lower than that grown with Hf[N(CH3)2]4. This tendency agrees with the leakage c.d. An equivalent SiO2 thickness (EOT) of 1.4 nm with 4.7 ′ 10-6 A/cm2 @-1 V has been obtained for the hafnium oxide films grown with Hf[N(C2H5)2]4 at 280°. .