Syntheses and structures of novel hafnium chloroamido mono-amidinate and mono-guanidinate as precursors for HfO2 thin film

The reactions between HfCl2[N(SiMe3)2]2 and one or two equivalents of [iPrNC(Me)NiPr]Li and iPr–NCN–iPr, at room temperature in toluene, gave the novel chloroamido-amidinato-hafnium HfCl[N(SiMe3)2]2[iPrNC(Me)NiPr] (1) and chloroamido-guanidinato-hafnium HfCl2[N(SiMe3)2][iPrNC(N(SiMe3)2)NiPr] (2) compounds, respectively. Compounds 1 and 2 were characterized by NMR and X-ray single crystal diffraction analysis. Their reaction towards alcohol was studied in order to check the dependency between molecular structure and HfO2 Atomic Layer Deposition (ALD) specifications.

Novel chloroamido-mono-amidinato-hafnium HfCl[N(SiMe3)2]2[iPrNC(Me)NiPr] and chloroamido-mono-guanidinato-hafnium HfCl2[N(SiMe3)2][iPrNC(N(SiMe3)2)NiPr] compounds have been synthesized by the reaction between HfCl2[N(SiMe3)2]2 and one or two equivalents of [iPrNC(Me)NiPr]Li and iPr–NCN–iPr at room temperature in toluene. The compounds were fully characterized by proton NMR, elemental analysis and single crystal X-ray diffraction. Volatility and selective reaction towards –OH species of the mono-amidinato derivative (in contrast with guanidinato-one) confirmed its suitable molecular design as precursor for HfO2 thin film elaboration by ALD process.Figure optionsDownload as PowerPoint slide