On the Impact of Strained PECVD Nitride Layers on Oxide Precipitate Nucleation in Silicon

PECVD nitride layers with different layer stress ranging from about 315 MPa to −1735 MPa were deposited on silicon wafers with similar concentration of interstitial oxygen. After a thermal treatment consisting of nucleation at 650°C for 4 h or 8 h followed annealing 780°C 3 h + 1000°C 16 h in nitrogen, the profiles of the oxide precipitate density were investigated. The binding states of hydrogen in the layers was investigated by FTIR. There is a clear effect of the layer stress on oxide precipitate nucleation. The higher the compressive layer stress is the higher is a BMD peak below the front surface. If the nitride layer is removed after the nucleation anneal the BMD peak below the front surface becomes lower. It is possible to model the BMD peak below the surface by vacancy in-diffusion from the silicon/nitride interface. With increasing duration of the nucleation anneal the vacancy injection from the silicon/nitride interface decreases and with increasing compressive layer stress it increases. © The Author(s) 2019

The band-gap of amorphous and well-ordered Al2O3 on Ni3Al(100)

The vibrational and electronic properties of amorphous and well-ordered alumina formed on Ni3Al(100) were investigated using high-resolution electron energy loss spectroscopy. The structure of well-ordered alumina was analyzed by low-energy electron diffraction. The amorphous Al2O3 films are prepared by adsorption of O-2 at room temperature, while the well-ordered Al2O3 are obtained by direct oxidation of Ni3Al at 1150 K. The band gap energy is similar to3.2 and similar to4.3 eV for amorphous alumina and well-ordered alumina thin films respectively. The lowering of the band gap with respect to the bulk value of Al2O3 is associated with defect-induced states located in the band gap. (C) 2001 American Institute of Physics

Ultra thin Al2O3films grown on Ni3Al(100)

The oxidation of the Ni3Al(1 0 0) surface at 1100 K with 2000 1 was investigated by Auger electron spectroscopy (AES), low energy electron diffraction (LEED), high resolution electron energy loss spectroscopy (EELS), and scanning tunneling microscopy (STM). Oxidation at 1100 K, leads to the formation of a well ordered, ultra thin Al2O3 film on top of Ni3Al(1 0 0). The oxide grows with the (1 1 1) plane of the gamma'-Al2O3 parallel to the surface plane of the substrate. The observed LEED pattern of the Al2O3 film is explained by a hexagonal structure in two domains which are perpendicularly oriented with respect to each other. The lattice constant of the hexagonal structure amounts to similar to3 Angstrom. In addition, two hexagonal superstructures with a lattice constant of 17.5 and 54 Angstrom were found on the oxide surface. (C) 2002 Published by Elsevier Science B.V

Co on thin Al2O3 films grown on Ni3Al(100)

The growth of Co on thin Al2O3 layers on Ni3Al(1 0 0) was investigated by Auger electron spectroscopy, high resolution electron energy loss spectroscopy (EELS), and scanning tunneling microscopy. At 300 K, Co grows in three-dimensional clusters on top of the Al2O3 layer. A defect structure of the alumina layer plays a crucial role during the early stage of Co growth. After deposition of 10 Angstrom of Co, a complete screening of the dipoles of the Al2O3 layer due to the Co film is found in the EELS measurements. Annealing the Co film reveals a process of coalescence of Co clusters and, above 700 K, diffusion of the Co atoms through the oxide film into the substrate takes place. (C) 2003 Elsevier Science B.V. All rights reserved