Synthetic and Spectroscopic Study of the Mechanism of Atomic Layer Deposition of Tin Dioxide

Synthesis, characterisation and thermal properties of Sn(ii) pyrrolide complexes

SnO is a rare example of a stable p-type semiconductor material. Here, we describe the synthesis and characterisation of a family of Sn(ii) pyrrolide complexes for future application in the MOCVD and ALD of tin containing thin films. Reaction of the Sn(ii) amide complex, [{(Me3Si)2N}2Sn], with the N,N-bidentate pyrrole pro-ligand, L1H, forms the hetero- and homoleptic complexes [{L1}Sn{N(SiMe3)2}] (1) and [{L1}2Sn] (2), respectively, bearing the 2-dimethylaminomethyl-pyrrolide ligand (L1). Reaction of [{(Me3Si)2N)}2Sn] with the pyrrole-aldimine pro-ligands, L2H-L7H, results in the exclusive formation of the homoleptic bis-pyrrolide complexes [{L2-7}2Sn] (3-8). All complexes have been characterised by elemental analysis and NMR spectroscopy, and the molecular structures of complexes 1-5 and 8 are determined by single crystal X-ray diffraction. TG analysis and isothermal TG analysis have been used to evaluate the potential utility of these systems as MOCVD and ALD precursors.

Synthesis, Characterization, and Thermal Properties of N-alkyl β-Diketiminate Manganese Complexes

A series of N, N'-dialkyl-β-diketiminato manganese(II) complexes was synthesized and characterized by single crystal X-ray diffraction, UV-vis and FTIR spectroscopy, and then assayed for volatility, thermal stability, and surface reactivity relevant to vapor-phase film growth processes. Bis( N, N'-dimethyl-4-amino-3-penten-2-imine) manganese(II), 1, and bis( N- N'-diisopropyl-4-amino-3-penten-2-imine) manganese(II), 2, specifically, emerge as the most promising candidates, balancing volatility (sublimation temperatures < 100 °C at 100 mTorr) with coordinative unsaturation and reactivity, as revealed by rapid release of ligand in the presence of a silica surface. Good correlation is observed between buried volume calculations and relative surface reactivity data, indicating that metal availability resulting from sterically open ligand alkyl substituents increases surface reactivity. The thermal stability, volatility, and reactivity exhibited by these compounds render them promising precursors for the growth of manganese oxide films via vapor-phase growth processes.