Growth of clean (<5% carbon), stoichiometric false(normalTi:N=1.15±0.1false) titanium nitride thin films on Si(100) substrates from the reaction of tetrakisdimethylamido titanium, normalTifalse(NMe2)4 , and ammonia is reported. Films were deposited using a novel gas delivery system which allowed the reactants to be mixed at elevated pressures with the substrate held in high vacuum. The films were analyzed using Rutherford backscattering and Auger electron spectroscopy while the gas‐phase chemistry was monitored by mass spectrometry. The quality of the films was measured as a function of gas pressure, reactant ratio, and substrate temperature. Growth on patterned wafers gave information on reactant sticking coefficients and surface mobilities. The reaction of normalTifalse(NMe2)4 with 15NH3 or ND3 clearly showed that both the nitrogen in a clean normalTiN film and the hydrogen (deuterium) in the gaseous dimethylamine product are derived exclusively from the ammonia. Mass spectrometry studies indicate that the reactive intermediate may be a high molecular weight oligomer consisting of Ti, N, H, and perhaps C. These finding are discussed both in terms of their impact on understanding the growth mechanism, as well as on the potential of this precursor system to be used in a manufacturing process.

The interaction between ammonia and the benzene radical cation has been investigated by gas-phase studies of mass selected ion clusters {C(6)H(6)-(NH(3))(n=0-8)}(+) via tandem quadrupole mass spectrometry and through calculations. Experiments show a special stability for the cluster ion that contains four ammonias: {C(6)H(6)(NH(3))(4)}(+). Calculations provide evidence that the first ammonia forms a weak dative bond to the cyclohexadienyl radical cation, {C(6)H(6)-NH(3)}(+), where there is a transfer of electrons from ammonia to benzene. Additional solvating ammonia molecules form stabilizing hydrogen bonds to the ring-bound ammonia {C(6)H(6)-NH(3)}(+).(NH(3))(n), which cause cooperative changes in the structure of the cluster complex. Free ammonia is a weak hydrogen bond donor, but electron transfer from NH(3) to the benzene ring that strengthens the dative bond will increase the hydrogen acidity and the strength of the cluster hydrogen bonds to the added ammonia. A progressive "tightening" of this dative bond is observed upon addition of the first, second, and third ammonia to give a cluster stabilized by three N-(+)H x N hydrogen bonds. This shows that the energetic cost of tightening the dative bond is recovered with dividends in the formation of stable cluster hydrogen bonds.

The interactions of the simple amine functional groups with the surfaces of ZnO aerosol nanoparticles have been investigated. The ZnO particles were synthesized from the metal−organic precursor methylzinc isopropoxide {[CH 3 ZnOCH(CH 3 ) 2 ] 4 , MZI}. Solid MZI was evaporated at 85−120 °C, and then swept by an inert carrier gas at atmospheric pressure through a tube furnace operating at 300−900 °C. Thermal decomposition of MZI led to the formation of stoichiometric ZnO nanoparticles of mobility diameter 3−50 nm. The size, structure, and composition of synthesized particles were characterized by differential mobility analysis (DMA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform IR spectroscopy (FTIR). The aerosolized ZnO nanoparticles were reacted with two gas-phase organic species: 1-butylamine and 1-hexylamine. Uptake was monitored by tandem differential mobility analysis (T-DMA). These results represent the first work on surface functionalization of ZnO nanoparticles in the aerosol state. They establish a new approach for manipulating quantum dot materials in the aerosol state.

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