Mononuclear precursor for MOCVD of HfO2 thin films

We report the precursor characteristics of a novel mononuclear mixed alkoxide compound [Hf(O(i)Pr)2(tbaoac)2] and its application towards MOCVD of HfO2 thin films in a production tool CVD reactor

Guanidinate-stabilized monomeric hafnium amide complexes as promising precursors for MOCVD of HfO2

Novel guanidinato complexes of hafnium [Hf{eta2-(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 hafnium amide complexes 1-3 and {[mu2-NC(NMe2)2][NC(NMe2)2]2HfCl}2 (4) using a salt metathesis reaction, are reported. Single-crystal X-ray diffraction analysis revealed that compounds 1-3 were monomers, while compound 4 was found to be a dimer. The observed fluxional behavior of compounds 1-3 was studied in detail using variable-temperature and two-dimensional NMR techniques. The thermal characteristics of compounds 1-3 seem promising for HfO2 thin films by vapor deposition techniques. Metal-organic chemical vapor deposition experiments with compound 2 as the precursor resulted in smooth, uniform, and stoichiometric HfO2 thin films at relatively low deposition temperatures. The basic properties of HfO2 thin films were characterized in some detail

Thin Films of HfO2 for High-k Gate Oxide Applications from Engineered Alkoxide- and Amide-Based MOCVD Precursors

HfO2 thin films with thickness between 2 and 20 nm were grown by liquid injection metallorganic chemical vapor deposition, LI-MOCVD, on SiOx/Si (100) substrates. Different mononuclear precursors ([Hf(OPri)(2)(tbaoac)(2)], [Hf(NEt2)(2)(guanid)(2)], and [Hf(OBut)(2)(dmae)(2)] were tested in combination with different solvents. Growth rate, surface morphology, crystal structure, and crystal density of the as-deposited films were analyzed as a function of deposition temperature. The influence of postdeposition annealing on the densification and crystallization was studied. Correlation of the structural properties with the electrical properties of metal insulator semiconductor capacitors with Pt top electrodes is discussed. Fully silicided metal gate stacks are additionally discussed for selected samples. (c) 2007 The Electrochemical Society

Precursor chemistry for TiO2: titanium complexes with a mixed nitrogen/oxygen ligand sphere

Novel mixed amido-malonato complexes of titanium are reported. The complexes were synthesized by partially replacing the amido groups from the complexes [Ti(NMe2)(4)] and [Ti(NEt2)(4)] via Bronstedt acid/base reactions, using the malonate-ligands di-isopropylmalonate (Hdpml) and di-tert-butylmalonate (Hdbm]). Four representative complexes were synthesized and fully characterised by H-1 NMR, C-13 NMR, CHN analysis and mass spectrometry. The crystal structures of the six-coordinated complexes [Ti(NMe2)(2)(dbml)(2)] (3) and [Ti(NEt2)(2)(dbml)(2)] (4) are presented and discussed. The complexes are solids and the chemical and thermal characteristics of the complexes strongly depend on the substitution at the malonate ligand. While dpml containing complexes show a promising behaviour for classical MOCVD, dbml containing complexes seem to be more suitable for liquid injection-metal-organic chemical vapour deposition (LI-MOCVD). Based on its thermal characteristics, the most promising complex for thermal CVD, [Ti(NEt2)(2)(dpml)(2)] (2) was selected for preliminary MOCVD experiments, which indicate a good suitability for the deposition of TiO2 thin films