Synthesis and characterisation of zirconium–amido guanidinato complex: a potential precursor for ZrO₂thin films

Abstract

A new zirconium complex, bis-(ethylmethylamido)-bis-(N,N'-diisopropyl-2-ethylmethylamidoguanidinato)-zirconium(iv) {[(N(i)Pr)(2)C(NEtMe)](2)Zr(NEtMe)(2)}, was synthesised by partial replacement of amide ligands with bidentate guanidinate ligands. The monomeric Zr complex was characterised by (1)H-NMR, (13)C-NMR, EI-MS, elemental analysis, and single crystal X-ray diffraction studies. The thermal properties of the compound was studied by thermogravimetric and differential thermal analysis (TG/DTA). The new Zr compound is thermally stable and can be sublimed quantitatively which renders it promising for thin film growth using vapor deposition techniques like chemical vapor deposition (CVD) and atomic layer deposition (ALD). The use of this complex for CVD of ZrO(2) on Si(100) substrates was attempted in combination with oxygen as the oxidant. Stoichiometric ZrO(2) films with preferred orientation at lower growth temperatures was obtained and the films were almost carbon free. The preliminary electrical characterisation of ZrO(2) films showed encouraging results for possible applications in dielectric oxide structures.

Atomic Layer Deposition of Groups 4 and 5 Transition Metal Oxide Thin Films: Focus on Heteroleptic Precursors

“…In the case of alkylamide‐alkoxides, alkylamide‐Cps, and alkylamide‐guanidinates, the homoleptic alkylamide is used as the starting material. To form alkylamide‐Cps and alkylamide‐guanidinates, Cp or carbodiimide ligands are added and ligand‐exchange reactions produce the desired alkylamide‐Cps or alkylamide‐guanidinates, as can be seen in Reactions 2 and 3 …”

“…Novel chemistry for ALD and CVD precursors has recently been introduced using guanidinate ligands . The flexibility of the guanidinate structure with respect to the modification of its steric and electronic properties makes it an interesting ligand.…”

Thin Films of ZrO2 for High‐k Applications Employing Engineered Alkoxide‐ and Amide‐Based MOCVD Precursors

“…[8] The precursor complexes are volatile monomers displaying promising thermal properties suitable for CVD applications. The vaporization and decomposition temperatures for the precursors, as deduced from the thermal analysis data, are summarized in Table 1.…”

Syntheses and structures of non-symmetric guanidinato zirconium and hafnium complexes and their catalytic behavior for ethylene polymerization

“…Guanidinate-supported titanium imido complexes were prepared and firstly used as a catalyst for alkyne hydroamination [10]. Recently, zirconium-amido guanidinato complex was used as a potential precursor for the CVD of ZrO 2 thin films [11].…”