Deposition of Tungsten Boride by Ion Beam Sputtering

1990 ◽  
Vol 181 ◽  
Author(s):  
F. Meyer ◽  
D. Bouchier ◽  
V. Stambouli ◽  
G. Gautherin

ABSTRACTRefractory metal compounds, such as nitrides or borides, are attractive candidates for diffusion barrier between silicon and aluminium in VLSI technology. We studied tungsten boride films deposited on silicon (100) by ion beam sputter deposition (IBSD).The tungsten boride films were prepared by sputtering a W2B5 target by argon ions with energy ranging from 0.5 to 2keV. The substrate temperature was varied from room temperature to 630°C. Finally, the films were patterned by selective wet etching in order to characterize the resulting Schottky diodes. We observed that a boron loss occurs during deposition, probably due to the backscattering of sputtered boron on previously deposited W atoms. By in situ AES analysis, we verified that a 5 nm thick layer acts as a diffusion barrier for silicon up to about 630°C, for all deposition conditions. The films properties were found to depend weakly on the primary ion energy and on the substrate temperature. All the films have resistivity at room temperature in the range of about 250 µΩ cm. The measured density, in the range of 12 g/cm3, is very close to that of WB2 bulk material, while the intrinsic stress of the films remains compressive and in the range of -lGPa. This value is notably lower than what we measured for pure tungsten prepared under similar deposition conditions.

1995 ◽  
Vol 388 ◽  
Author(s):  
Yoshihisa Watanabe ◽  
Yoshikazu Nakamura ◽  
Shigekazu Hirayama ◽  
Yuusaku Naota

AbstractAluminum nitride (AlN) thin films have been synthesized by ion-beam assisted deposition method. Film deposition has been performed on the substrates of silicon single crystal, soda-lime glass and alumin A. the influence of the substrate roughness on the film roughness is studied. the substrate temperature has been kept at room temperature and 473K and the kinetic energy of the incident nitrogen ion beam and the deposition rate have been fixed to 0.5 keV and 0.07 nm/s, respectively. the microstructure of the synthesized films has been examined by X-ray diffraction (XRD) and the surface morphology has been observed by atomic force microscopy(AFM). IN the XRD patterns of films synthesized at both room temperature and 473K, the diffraction line indicating the alN (10*0) can be discerned and the broad peak composed of two lines indicating the a1N (00*2) and a1N (10*1) planes is also observed. aFM observations for 100 nm films reveal that (1) the surface of the films synthesized on the silicon single crystal and soda-lime glass substrates is uniform and smooth on the nanometer scale, (2) the average roughness of the films synthesized on the alumina substrate is similar to that of the substrate, suggesting the evaluation of the average roughness of the film itself is difficult in the case of the rough substrate, and (3) the average roughness increases with increasing the substrate temperature.


1998 ◽  
Vol 526 ◽  
Author(s):  
B. Holzapfel ◽  
V. Betz ◽  
M.A. Arranz ◽  
N. Reger ◽  
L. Schultz

AbstractBiaxially oriented yttria stabilized zirconia (YSZ) and Pr6O11 buffer layers were grown at room temperature by Ion-Beam Assisted Laser Deposition (IBALD) on metal substrates. Dependent on deposition parameters, IBALD grown films showed in-plane orientations of about 10° FWHM (full-width at half maximum) for both systems. In contrast to the YSZ system, where best in plane alignment is found for a [111] direction oriented parallel to the ion beam, the Pr6O11 system shows best in-plane alignment at nearly gracing incidence of the ion beam. An additional thin intermediate CeO2 layer improves the heteroepitaxial growth of YBCO on highly biaxially oriented YSZ films. Pulsed Laser Deposition (PLD) was also used to grow epitaxial CeO2 buffer layers directly on biaxially textured Ni-tapes. SIMS investigations showed an interdiffusion zone of about 0.5μm at standard deposition conditions, but no enhanced grain boundary diffusion could be observed.


1985 ◽  
Vol 54 ◽  
Author(s):  
En Ma ◽  
Bai-Xin Liu ◽  
Xin Chen ◽  
Heng-De Li

ABSTRACTA systematic study was performed to investigate the ion beam induced metal nitride formation by direct nitrogen implantation into 10 selected metals, either of thin film or bulk material. An X-ray diffractometer, together with a specially-designed Seemann-Bohlin attachment, was employed to provide fast and reliable phase identification in the thin implanted layer. The results show that room temperature nitrogen implantation can lead to the formation of many, but not all, of the equilibrium metal nitrides. The formation of metal nitrides by implantation is discussed in terms of the thermodynamic condition and the readiness of structural trans format ion.


2005 ◽  
Vol 868 ◽  
Author(s):  
Liliana Stan ◽  
Paul N. Arendt ◽  
Raymond F. DePaula ◽  
Igor Usov ◽  
James R. Groves

AbstractThe variation in the substrate temperature during ion beam assisted deposition (IBAD), which employs the use of energetic ions to bombard a growing film, has been shown to influence the quality of crystalline texture in MgO films. Determining the acceptable deviation from the optimum ion to molecule ratio for different substrate temperatures establishes the optimum MgO deposition conditions. For each fixed deposition temperature, a set of samples was produced by varying the ion assist beam current from sample to sample while keeping the deposition rate constant. In this way, the ion to molecule ratio was modified and the range of achieving well textured films was determined. The investigation of the MgO texture dependence on the substrate temperature reveals that the best in-plane alignment is obtained at ˜ 25°C. At this temperature, MgO films with in-plane orientation distribution as low as 3.7° full width at half maximum (FWHM) have been attained. MgO films deposited at temperatures higher than 100°C have broad in-plane alignment. Although, the deposition at the lowest temperature (-150°C) did not improve the in-plane texture, the acceptable deviation from the optimum ion to molecule ratio for achieving biaxially textured films was the largest. As a trend, the acceptable ion to molecule deviation decreases with increasing substrate temperature. This is especially important for continuous IBAD MgO depositions where less restrictive conditions are desired.


1990 ◽  
Vol 187 ◽  
Author(s):  
K. S. Grabowski ◽  
R. A. Kant

AbstractEpitaxial growth of Ni (111) on Si (111) has previously been obtained at room temperature by 25-keV-Ni ion beam assisted deposition, where both ion and vapor fluxes were incident at 45° to the specimen normal. This work explores the effect of a wider range of deposition conditions on epitaxial film quality. Nominally 300-nm-thick films were deposited at room temperature on Si (111) and other substrates. The substrates were sputter cleaned by the Ni ion beam immediately prior to deposition. Ion energies of 25 to 175 keV, relative ion to vapor fluxes R from 0 to 0.1, and vapor deposition rates of 0.05 to 0.5 nm/s were examined. Bragg-Brentano symmetric x-ray diffraction evaluated film quality while Ni (220) grazing-incidence x-ray diffraction rocking curves verified film epitaxy. Film quality changed gradually over these deposition parameters, with an optimum at 25 keV and an R of about 0.01. At higher energies and R values sputtering and radiation damage destroyed the film epitaxy


1994 ◽  
Vol 363 ◽  
Author(s):  
Robert F. Davis ◽  
Daniel J. Kester ◽  
K. Shawn Ailey

AbstractBoron nitride (BN) thin films have been grown on the (100) surfaces of Si, diamond, Ni and Cu via ion beam assisted deposition (IBAD) using electron beam evaporation of B in tandem with N and Ar ion bombardment within the ranges of substrate temperature and ion flux of 200–700°C and 0.20–0.30 mA/Cm2, respectively, Fourier-transform infrared spectroscopy (FTIR) and high resolution transmission electron microscopy (HRTEM) revealed a growth sequence of amorphous (a-BN), hexagonal (h-BN) and cubic (c-BN) layers on Si and diamond under most conditions. This sequence is attributed primarily to increasing biaxial compressive stress with film thickness due to interstitial Ar incorporation observed via Rutherford backscattering spectroscopy (RBS). The effect of deposition conditions, specifically substrate temperature and bombardment intensity, on the film growth was studied. Increasing the substrate temperature above 400°C led to the onset of the cubic phase at a greater film thickness, while increased ion flux led to earlier growth of this phase. These results may be explained by the relaxation of intrinsic stress in the films at higher temperatures due to increased adatom mobility and to increased intrinsic stress in the films resulting from increased ion bombardment, respectively. Lower temperatures led to mixed phase growth. A minimum substrate temperature (200–300°C) is required for nucleation and growth of single phase c-BN by this technique. A combination of h-BN and c-BN was deposited on Ni; only h-BN was obtained on Cu substrates.


1993 ◽  
Vol 320 ◽  
Author(s):  
J. Teichert ◽  
L. Bischoff ◽  
E. Hesse ◽  
D. Panknin ◽  
W. Skorupa

ABSTRACTThe maskless ion implantation with the focused ion beam as a new method for ion beam synthesis of cobalt sulicide wires is presented. In order to perform the implantation a special achromatic mass separator was implemented into the ion column, liquid alloy ion sources for cobalt ions were developed and a substrate heating was built. Ion implantation was performed with 30 keV Co+ and 60 keV Co++ ions. The dose dependence for room temperature implantation and the influence of the substrate temperature were investigated.


1993 ◽  
Vol 316 ◽  
Author(s):  
J. Teichert ◽  
L. Bischoff ◽  
E Hesse ◽  
D. Panknin ◽  
W. Skorupa

ABSTRACTThe maskless ion implantation with the focused ion beam as a new method for ion beam synthesis of cobalt suicide wires is presented. In order to perform the implantation a special achromatic mass separator was implemented into the ion column, liquid alloy ion sources for cobalt ions were developed and a substrate heating was built. Ion implantation was performed with 30 keV Co+ and 60 keV Co++ ions. The dose dependence for room temperature implantation and the influence of the substrate temperature were investigated.


1992 ◽  
Vol 268 ◽  
Author(s):  
M.A. Djouadi ◽  
D. BOUCHIER

ABSTRACTIn IBAD BN and RIBSD Si3N4 layers deposited at room temperature, the internal stress can always be reduced below -1 GPa by a post-deposition annealing. When the deposition temperature is increased up to 600°C, the stress in Si3N4 layers is not significantly reduced and, in IBAD BN films, it is even greater than expected from the development of the thermal stress, which indicates that no relaxation of the stress occurs during deposition. This implies that the spatial extent of the ion peening effect may largely exceed the penetration depth of ions and of recoil atoms in the solid. In order to confirm this hypothesis, sequences of deposition/in situ annealing/deposition have been performed. In RIBSD films, the relaxation of the annealed sublayer can be observed. In IBAD films, the deposition of the upper layer results in an increase of the stress in the superficial zone of the annealed sublayer.


Author(s):  
T. Baird ◽  
J.R. Fryer ◽  
S.T. Galbraith

Introduction Previously we had suggested (l) that the striations observed in the pod shaped crystals of β FeOOH were an artefact of imaging in the electron microscope. Contrary to this adsorption measurements on bulk material had indicated the presence of some porosity and Gallagher (2) had proposed a model structure - based on the hollandite structure - showing the hollandite rods forming the sides of 30Å pores running the length of the crystal. Low resolution electron microscopy by Watson (3) on sectioned crystals embedded in methylmethacrylate had tended to support the existence of such pores.We have applied modern high resolution techniques to the bulk crystals and thin sections of them without confirming these earlier postulatesExperimental β FeOOH was prepared by room temperature hydrolysis of 0.01M solutions of FeCl3.6H2O, The precipitate was washed, dried in air, and embedded in Scandiplast resin. The sections were out on an LKB III Ultramicrotome to a thickness of about 500Å.


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