Only a few M–N bonded divalent group 14 precursors are available for vapor deposition, in particular for Ge and Pb. A majority of the reported precursors are dicoordinated with the Sn(II) amidinates, the only tetracoordinated examples. No Ge(II) and Pb(II) amidinates suitable for vapor deposition have been demonstrated. Herein, we present tetracoordinated Ge(II), Sn(II), and Pb(II) complexes bearing two sets of chelating 1,3-di- tert -butyltriazenide ligands. These compounds are thermally stable, sublime quantitatively between 60 and 75 °C (at 0.5 mbar), and show ideal single-step volatilization by thermogravimetric analysis.

Group 11 thin films are desirable as interconnects in microelectronics. Although many M–N bonded Cu precursors have been explored for vapor deposition, there is currently a lack of suitable Ag and Au derivatives. Herein, we present monovalent Cu, Ag and Au 1,3-di-tert-butyltriazenides that have potential for use in vapor deposition. These compounds possess thermal stability and volatility that rival that of current state-of-the-art group 11 precursors with bidentate M–N bonded ligands. All compound sublime quantitatively between 120 and 130 °C at 0.5 mbar. Thermogravimetric analysis showed the Cu and Ag compounds both volatilized at ~200 °C with 0 and 2% residual mass, respectively. The Au triazenide showed two separated mass loss events at ~175 and 240 °C, and 35% residual mass. The crystal structure of the Cu compound showed a dimer, whilst the Ag and Au derivatives were tetrameric. Nuclear magnetic resonance spectroscopy showed dimers for the Cu and Au compounds and a dimer/tetramer equilibrium for the Ag compound. Electronic energies from density functional theory calculations confirmed dimeric preference for the Cu triazenide while Ag and Au preferred the tetrameric. However, all three compounds showed dimeric preference when accounting for entropy. Dimers are, therefore, expected to dominate in the gas phase for all three compounds during sublimation. Natural bond orbital analysis was used to identify orbital interactions important for the dimer/tetramer preference. Three factors were identified, in conjunction with strong metal-metal interactions, to increase the preference for rhombic tetramers.

Group 11 thin films are desirable as interconnects in microelectronics. Although many M−N-bonded Cu precursors have been explored for vapor deposition, there is currently a lack of suitable Ag and Au derivatives. Herein, we present monovalent Cu, Ag, and Au 1,3-di-tert-butyltriazenides that have potential for use in vapor deposition. Their thermal stability and volatility rival that of current state-of-the-art group 11 precursors with bidentate M−N-bonded ligands. Solution-state thermolysis of these triazenides yielded polycrystalline films of elemental Cu, Ag, and Au. The compounds are therefore highly promising as single-source precursors for vapor deposition of coinage metal films.

<p>The number of M–N bonded divalent group 14 precursors suitable for atomic layer deposition is limited, in particular for Ge and Pb. A majority of the reported precursors are dicoordinated, with the only tetracoordinated example being the Sn(II) amidinate. No such Ge(II) and Pb(II) compounds have been demonstrated. Herein, we present tetracoordinated Ge(II), Sn(II) and Pb(II) complexes bearing two sets of the bidentate 1,3-di-<i>tert</i>-butyl triazenide ligands. These compounds are highly volatile and show ideal behavior by thermogravimetric analysis. However, they have unusual thermal properties and exhibit instability during sublimation. Interestingly, the instability is not only temperature dependent but also facilitated by reduced pressure. Using quantum-chemical density functional theory, a gas-phase decomposition pathway was mapped out. The pathway account for the unusual thermal behavior of the compounds and is supported by electron impact mass spectrometry data.</p>

<p>The number of M–N bonded divalent group 14 precursors suitable for atomic layer deposition is limited, in particular for Ge and Pb. A majority of the reported precursors are dicoordinated, with the only tetracoordinated example being the Sn(II) amidinate. No such Ge(II) and Pb(II) compounds have been demonstrated. Herein, we present tetracoordinated Ge(II), Sn(II) and Pb(II) complexes bearing two sets of the bidentate 1,3-di-<i>tert</i>-butyl triazenide ligands. These compounds are highly volatile and show ideal behavior by thermogravimetric analysis. However, they have unusual thermal properties and exhibit instability during sublimation. Interestingly, the instability is not only temperature dependent but also facilitated by reduced pressure. Using quantum-chemical density functional theory, a gas-phase decomposition pathway was mapped out. The pathway account for the unusual thermal behavior of the compounds and is supported by electron impact mass spectrometry data.</p>