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New convenient procedures for the preparation of ammonia monochloroborane (NH₃BH₂Cl) and cyclotriborazane [(BH₂NH₂)₃] are described. Crystal structures have been determined by single-crystal X-ray diffraction. Strong H...Cl...H bifurcated hydrogen bonding and weak N--H...H dihydrogen bonding are observed in the crystal structure of ammonia monochloroborane. When heated at 50 °C or under vacuum, ammonia monochloroborane decomposes to (NH₂BHCl)x, which was characterized by NMR, elemental analysis, and powder X-ray diffraction. Redetermination of the crystal structure of cyclotriborazane at low temperature by single-crystal X-ray diffraction analysis provides accurate hydrogen positions. Similar to ammonia borane, cyclotriborazane shows extensive dihydrogen bonding of N--H‥H and B--H...H bonds with Hδ+‥Hδ+‥ interactions in the range of 2.00--2.34 A. [ABSTRACT FROM AUTHOR]

In the present study, SiO 2 was deposited using the atomic layer deposition (ALD) with a 1,2-bis(diisopropylamino)disilane (BDIPADS) precursor. The use of this precursor exhibited a higher growth rate and lower initial growth temperature than the use of diisopropylaminosilane (DIPAS) did. The ALD reaction using BDIPADS produced SiO 2 with excellent quality owing to the self-catalytic reaction between the amine ligand and O 3 ; therefore, the SiO 2 film has no impurities. When the growth temperature was increased gradually, the stoichiometry and density of SiO 2 were improved also because the reaction between surface adsorbate species was nearly complete. ALD SiO 2 exhibited a higher dielectric constant than the bulk SiO 2 did, from the metal-oxide-semiconductor capacitor, because of the incorporated hydroxyl groups in the film. Furthermore, the etching characteristics were modulated by changing the growth temperature to ensure that the film can be used as a hard mask for lithography. From the DFT calculation, high reaction energy between the BDIPADS and Si–OH was observed. Moreover, the Si–Si cleavage results in the existence additional reaction sites, such as amine group, allowing low-temperature growth and enhanced productivity. Therefore, the number of Si atoms in a molecule affects the growth rate and initial growth temperature to ensure that BDIPADS is a highly excellent precursor for the SiO 2 deposition; therefore, its use can lead to a remarkably high productivity. Unlabelled Image • SiO 2 is deposited by atomic layer deposition using aminodisilane precursor. • High growth rate is available at the low growth temperature (50 °C). • Etching characteristics were modified using various growth temperatures of ALD SiO 2. • On the basis of DFT calculation, BDIPADS is favorably adsorbed on the Si substrate. • High growth rate of ALD SiO 2 using BDIPADS was originated from Si–Si cleavage. [ABSTRACT FROM AUTHOR]