Molecular Beam Epitaxy of Boron Nitride Thin Films and Their Analytical Characterization

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.

Author(s):  
A. K. Rai ◽  
R. S. Bhattacharya ◽  
M. H. Rashid

Ion beam mixing has recently been found to be an effective method of producing amorphous alloys in the binary metal systems where the two original constituent metals are of different crystal structure. The mechanism of ion beam mixing are not well understood yet. Several mechanisms have been proposed to account for the observed mixing phenomena. The first mechanism is enhanced diffusion due to defects created by the incoming ions. Second is the cascade mixing mechanism for which the kinematicel collisional models exist in the literature. Third mechanism is thermal spikes. In the present work we have studied the mixing efficiency and ion beam induced amorphisation of Ni-Ti system under high energy ion bombardment and the results are compared with collisional models. We have employed plan and x-sectional veiw TEM and RBS techniques in the present work.


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.


2015 ◽  
Vol 833 ◽  
pp. 127-133
Author(s):  
Jie Yu ◽  
Jie Xing ◽  
Xiu Hua Chen ◽  
Wen Hui Ma ◽  
Rui Li ◽  
...  

La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) electrolyte thin films were fabricated on La0.7Sr0.3Cr0.5Mn0.5O2.75 (LSCM) porous anode substrates by Radio Frequency (RF) magnetron sputtering method. The compatibility between LSGM and LSCM was examined. Microstructures of LSGM thin films fabricated were observed by scanning electron microscope (SEM). The effect of substrate temperature on LSGM thin films was clarified by X-ray Diffraction (XRD). Deposition rate increases firstly at the range of 50°C~150°C, and then decreases at the range of 150°C ~300°C. After annealing, perovskite structure with the same growth orientation forms at different substrate temperature. Crystallite size decreases at first, to the minimum point at 150°C, then increases as substrate temperature rises.


1991 ◽  
Vol 237 ◽  
Author(s):  
Harry A. Atwater ◽  
C. J. Tsai ◽  
S. Nikzad ◽  
M.V.R. Murty

ABSTRACTRecent progress in low energy ion-surface interactions, and the early stages of ion-assisted epitaxy of semiconductor thin films is described. Advances in three areas are discussed: dynamics of displacements and defect incorporation, nucleation mechanisms, and the use of ion bombardment to modify epitaxial growth kinetics in atrulysurface-selective manner.


1999 ◽  
Vol 594 ◽  
Author(s):  
R. Spolenak ◽  
C. A. Volkert ◽  
K. Takahashi ◽  
S. Fiorillo ◽  
J. Miner ◽  
...  

AbstractIt is well known that the mechanical properties of thin films depend critically on film thickness However, the contributions from film thickness and grain size are difficult to separate, because they typically scale with each other. In one study by Venkatraman and Bravman, Al films, which were thinned using anodic oxidation to reduce film thickness without changing grain size, showed a clear increase in yield stress with decreasing film thickness.We have performed a similar study on both electroplated and sputtered Cu films by using chemical-mechanical polishing (CMP) to reduce the film thickness without changing the grain size. Stress-temperature curves were measured for both the electroplated and sputtered Cu films with thicknesses between 0.1 and 1.8 microns using a laser scanning wafer curvature technique. The yield stress at room temperature was found to increase with decreasing film thickness for both sets of samples. The sputtered films, however, showed higher yield stresses in comparison to the electroplated films. Most of these differences can be attributed to the different microstructures of the films, which were determined by focused ion beam (FIB) microscopy and x-ray diffraction.


2002 ◽  
Vol 197-198 ◽  
pp. 348-351 ◽  
Author(s):  
W.D Song ◽  
M.H Hong ◽  
Y.F Lu ◽  
W.J Wang ◽  
S.M Huang ◽  
...  

2000 ◽  
Vol 647 ◽  
Author(s):  
K. Deenamma Vargheese ◽  
G. Mohan Rao

AbstractIon bombardment during thin film growth is known to cause structural and morphological changes in the deposited films and thus affecting the film properties. These effects can be due to the variation in the bombarding ion flux or their energy. We have deposited titanium nitride films by two distinctly different methods, viz. Electron Cyclotron Resonance (ECR) plasma sputtering and bias assisted reactive magnetron sputtering. The former represents low energy (typically less than 30 eV) but high density plasma (1011cm−3), whereas, in the latter case the ion energy is controlled by varying the bias to the substrate (typically a few hundred volts) but the ion flux is low (109cm−3). The deposited titanium nitride films are characterized for their structure, grain size, surface roughness and electrical resistivity.


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