Ion-Assisted Pulsed Laser Deposition of Cubic Boron Nitride on Si (100) Substrates

1992 ◽  
Vol 285 ◽  
Author(s):  
T. A. Friedmann ◽  
K. F. Mccarty ◽  
E. J. Klaus ◽  
H. A. Johnsen ◽  
D. L. Medlin ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Ion Source ◽  
Laser Deposition ◽  
Reflection Spectroscopy ◽  
Grain Sizes ◽  
Broad Beam ◽  
Selected Area Electron Diffraction ◽  
Ir Reflection ◽  
Transmission Electron

ABSTRACTWe are studying the boron nitride system by using a pulsed excimer laser to ablate from hexagonal BN (hBN) targets to form cubic BN (cBN) films. We are depositing BN films on heated (400°C) Si (100) surfaces and are using a broad beam ion source operated with Ar and N2 source gasses to produce BN films with a high percentage of sp3-bonded cBN. The best films to date show ∼85% sp3-bonded BN as determined from infrared (IR) reflection spectroscopy. High resolution transmission electron microscopy (TEM) and selected area electron diffraction (SAD) confirm the presence of cBN in these samples. The films are polycrystalline and show grain sizes up to 500 Å.

scholarly journals Nucleation and Growth of Cubic Boron Nitride Films Produced by Ion-Assisted Pulsed Laser Deposition

1993 ◽  
Vol 316 ◽  
Author(s):  
T. A. Friedmann ◽  
D. L. Medlin ◽  
P. B. Mirkarimi ◽  
K. F. McCarty ◽  
E. J. Klaus ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Growth Parameters ◽  
Cubic Boron Nitride ◽  
Ion Source ◽  
Growth Time ◽  
Grain Sizes ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Parametric Studies ◽  
Boron Nitride Films

ABSTRACTWe are studying the boron nitride system by using a pulsed excimer laser to ablate from hexagonal BN (hBN) targets to form cubic BN (cBN) films. We are depositing BN films on heated (25 - 800°C) Si (100) surfaces and are using a broad-beam ion source operated with Ar and N2 source gasses to produce BN films with a high percentage of sp3-bonded cBN. In order to understand and optimize the growth and nucleation of cBN films, parametric studies of the growth parameters have been performed. The best films to date show >85% sp3-bonded BN as determined from Fourier-transform infrared (FTIR) reflection spectroscopy. High resolution transmission electron microscopy (TEM) and selected area electron diffraction confirm the presence of cBN in these samples. The films are polycrystalline and show grain sizes up to 30- 40 nm. We find from both the FTIR and TEM analyses that the cBN content in these films evolves with growth time. Initially, the films are deposited as hBN and the cBN nucleates on this hBN underlayer. Importantly, the position of the cBN IR phonon also changes with growth time. Initially this mode appears near 1130 cm-1 and the position decreases with growth time to a constant value of 1085 cm-1. Since in bulk cBN this IR mode appears at 1065 cm-1, a large compressive stress induced by the ion bombardment is suggested. In addition, we report on the variation in cBN percentage with temperature.

Preferentially Oriented Cubic Boron Nitride Films Grown on Si (001) Substrates by Ion Assisted Pulsed Laser Deposition

1992 ◽  
Vol 285 ◽  
Author(s):  
A. K. Ballal ◽  
L. Salamanca-riba ◽  
G. L. Doll ◽  
C. A. Taylor ◽  
R. Clarke
Keyword(s):  
Boron Nitride ◽  
Pulsed Laser Deposition ◽  
Cubic Boron Nitride ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Cross Sectional ◽  
Plan View ◽  
Si Substrates ◽  
Transmission Electron ◽  
Boron Nitride Films

ABSTRACTPreferentially oriented and extremely adherent cubic boron nitride films have been obtained using ion-assisted pulsed laser deposition on (001) Si substrates. The films were ∼ 1800 Å thick, optically transparent and formed an antireflective coating on the Si substrate. Infrared transmittance spectra showed a strong absorption peak at 1080 cm−1, indicating sp3 bonded film. Cross-sectional and plan-view transmission electron microscopy indicate that the cubic boron nitride films are polycrystalline having cubic zinc-blende crystal structure and a lattice constant of 3.62 Å. A preferred texture is observed with the [110] axis of cubic boron nitride parallel to [001] axis of silicon.

Ion‐assisted pulsed laser deposition of cubic boron nitride films

1994 ◽  
Vol 76 (5) ◽  
pp. 3088-3101 ◽  
Author(s):  
T. A. Friedmann ◽  
P. B. Mirkarimi ◽  
D. L. Medlin ◽  
K. F. McCarty ◽  
E. J. Klaus ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Pulsed Laser Deposition ◽  
Cubic Boron Nitride ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Boron Nitride Films

Ion Beam Assisted Deposition of Cubic Boron Nitride Thin Films

1991 ◽  
Vol 235 ◽  
Author(s):  
Daniel J. Kester ◽  
Russell Messier
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Boron Nitride ◽  
Ion Beam ◽  
Cubic Boron Nitride ◽  
Secondary Phase ◽  
Ion Energy ◽  
Ion Beam Assisted Deposition ◽  
Transmission Electron ◽  
Argon Ions

ABSTRACTBoron nitride thin films were grown using ion beam assisted deposition. Boron metal was evaporated, and the depositing film was bombarded by nitrogen and argon ions. The films were characterized using Fourier transform infrared spectroscopy, electron diffraction, transmission electron microscopy, and Rutherford backscattering. The thin films were found to be cubic boron nitride, consisting of 100–200 Å crystallites with a small amount of an amorphous secondary phase. The best conditions for depositing cubic boron nitride were found to be a substrate temperature of 400°C, bombardment by a 50:50 mixture of argon and nitrogen with a bombarding ion energy of 500 eV and a ratio of bombarding ions to depositing boron atoms of from 1.0 to 1.5 ions per atom.

Electron Microscopy Study of Cubic Boron Nitride Thin Films Grown by Ion -Assisted Pulsed Laser Deposition

1993 ◽  
Vol 311 ◽  
Author(s):  
D.D. Medlin ◽  
T.T. Friedmann ◽  
P.P. Mirkarimi ◽  
K.K. Mccarty ◽  
M.M. Mills
Keyword(s):  
Boron Nitride ◽  
Pulsed Laser Deposition ◽  
Ion Beam ◽  
Cubic Boron Nitride ◽  
Pulsed Laser ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Laser Deposition ◽  
Electron Microscopic ◽  
High Fraction

ABSTRACTWe present a microstructural study of boron nitride films grown by ion-assisted pulsed laser deposition. Fourier transform infra-red spectroscopy, electron energy loss spectroscopy, and electron diffraction measurements indicate that within the irradiated region of the substrate, the film consists of high fraction of cBN with a small amount of the turbostratic phase; outside of the irradiated region, only the turbostratic phase is detected. Conventional and high resolution electron microscopic observations of the boron nitride microstructure indicate that the cBN is in the form of twinned crystallites, up to 30 nm in diameter. We also observe particulates, formed by the laser pulse, that reduce the yield of cBN in the irradiated regions by shadowing local areas from the ion beam.

Microstructure of cubic boron nitride thin films grown by ion‐assisted pulsed laser deposition

1994 ◽  
Vol 76 (1) ◽  
pp. 295-303 ◽  
Author(s):  
D. L. Medlin ◽  
T. A. Friedmann ◽  
P. B. Mirkarimi ◽  
P. Rez ◽  
M. J. Mills ◽  
...  
Keyword(s):  
Thin Films ◽  
Boron Nitride ◽  
Pulsed Laser Deposition ◽  
Cubic Boron Nitride ◽  
Pulsed Laser ◽  
Laser Deposition

Pulsed Excimer Laser Ablation Deposition of Boron Nitride on Si (100) Substrates

1992 ◽  
Vol 242 ◽  
Author(s):  
T. A. Friedmann ◽  
K. F. McCarty ◽  
E. J. Klaus ◽  
D. Boehme ◽  
W. M. Clift ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Excimer Laser ◽  
Laser Energy ◽  
Cubic Phase ◽  
High Concentration ◽  
Force Microscopy ◽  
Ir Reflection ◽  
Transmission Electron ◽  
Ir Transmission ◽  
Background Gas

ABSTRACTWe are studying the boron nitride system by using a pulsed excimer laser to ablate from hexagonal BN (hBN) targets to form cubic BN (cBN) films. We are depositing BN films on heated (600°C) silicon (100) surfaces in a flowing (0- 10 sccm) ambient background gas of either NH3 or N2 of varying partial pressure (0–100 m Torr). Infrared (IR) reflection spectroscopy indicates the films have short-range hexagonal order. Some films grown at low laser energy densities have shown the cubic phase in IR transmission. Auger electron spectroscopy (AES) indicates the films are nitrogen deficient, which is linked to changes in the target stoichiometry with increasing laser fluence. Raman spectroscopy on the films shows only a strong background luminescence suggesting a high concentration of defects associated with the nitrogen vacancies. Atomic force microscopy (AFM) of the films shows a surface morphology that roughens as the growth rate increases. In order to improve the film stoichiometry it was necessary to actively enhance the nitrogen content of the films. It was found that bombarding films during growth with ions from an ion gun filled with NH3 gas increased the N/B ratio but did not enhance the cubic phase. RF biasing the substrate gave films which showed both cubic and hexagonal features in IR reflection. High resolution transmission electron microscopy (TEM) confirms the presence of cBN grains of ∼ 200Å size in films grown with an RF bias.

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