Preparation of molybdenum nitride thin films by N+ ion implantation

1992 ◽  
Vol 7 (2) ◽  
pp. 374-378 ◽  
Author(s):  
J-G. Choi ◽  
D. Choi ◽  
L.T. Thompson

A series of molybdenum nitride films were synthesized by implanting energetic nitrogen ions into molybdenum thin films. The resulting films were characterized using x-ray diffraction to determine the effects of nitrogen ion dose (4 × 1016−4 × 1017 N+/cm2), accelerating voltage (50–200 kV), and target temperature (∼298–773 K) on their structural properties. The order of structural transformation with increased incorporation of nitrogen ions into the Mo film can be summarized as follows: Mo → γ−Mo2N → δ−MoN. Nitrogen incorporation was increased by either increasing the dose or decreasing the ion energy. At elevated target temperatures the metastable B1–MoN phase was also produced. In most cases the Mo nitride crystallites formed with the planes of highest atomic density parallel to the substrate surface. At high ion energies preferential orientation developed so that the more open crystallographic directions aligned with the ion beam direction. We tentatively attributed this behavior to ion channeling effects.

2001 ◽  
Vol 15 (28n29) ◽  
pp. 1355-1360 ◽  
Author(s):  
UDAY LANKE ◽  
ANNETTE KOO ◽  
SIMON GRANVILLE ◽  
JOE TRODAHL ◽  
ANDREAS MARKWITZ ◽  
...  

Amorphous GaN films were deposited on various substrates viz. Si (100), quartz, glass, Al, stainless steel and glassy carbon by thermal evaporation of gallium in the presence of energetic nitrogen ions from a Kaufman source. The films were deposited at room temperature and 5 × 10-4 mbar nitrogen partial pressure. The effect of a low energy nitrogen ion beam during the synthesis of films was investigated for energies 40 eV and 90 eV. The N:Ga atomic ratio, bonding state, microstructure, surface morphology, and electrical properties of the deposited a-GaN films were studied by different characterisation techniques. The films are found to be X-ray amorphous in nature, which is confirmed by Raman spectroscopy. Rutherford Backscattering Spectroscopy (RBS) and Nuclear Reaction Analysis (NRA) indicate the N:Ga atomic ratio in the films. The 400-750 eV energy range is thought to be optimal for the production of single-phase amorphous GaN . The effect of ion-energy on optical, Raman, and electrical conductivity measurements of the films is also presented.


2003 ◽  
Vol 792 ◽  
Author(s):  
Shinichiro Aizawa ◽  
Yuka Nasu ◽  
Masami Aono ◽  
Nobuaki Kitazawa ◽  
Yoshihisa Watanabe

ABSTRACTIrradiation effect of low-energy nitrogen ion beam on amorphous carbon nitride (a-CNx) thin films has been investigated. The a-CNx films were prepared on silicon single crystal substrates by hot carbon-filament chemical vapor deposition (HFCVD). After deposition, the CNx films were irradiated by a nitrogen ion beam with energy from 0.1 to 2.0 keV. Irradiation effect on the film microstructure and composition was studied by SEM and XPS, focusing on the effect of nitrogen ion beam energy. Surface and cross sectional observations by SEM reveal that the as-deposited films show a densely distributed columnar structure and the films change to be a sparsely distributed cone-like structure after irradiation. It is also found that 2.0 keV ions skeltonize the films more clearly than 0.1 kev ions. Depth profiles of nitrogen in the films observed by XPS show that nitrogen absorption into films is more prominent after irradiation by 0.1 keV nitrogen ions than 2.0 keV ions.


1988 ◽  
Vol 128 ◽  
Author(s):  
Zhou Jiankun ◽  
Liu Xianghuai ◽  
Chen Youshan ◽  
Zheng Zhihong ◽  
Huang Wei ◽  
...  

ABSTRACTTitanium nitride films have been synthesized at room temperature by alternate deposition of titanium and bombardment by nitrogen ions with an energy of 40KeV. The component depth profiles and the structure of titanium nitride films were investigated by means of RBS, AES, TEM, XPS and X-ray diffraction. The results showed that titanium nitride films formed by ion beam enhanced deposition (IBED) had columnar structure and were mainly composed of TiN crystallites with random orientation. The oxygen contamination in titanium nitride films prepared by IBED was less than that of the deposited film without nitrogen ion bombardment. It was confirmed that a significant intermixed layer exists at the interface. The thickness of this layer was about 40 nm for the film prepared on iron plate. The mechanical properties of the film have been investigated. The films formed by IBED exhibited high hardness, improved wear resistance and low friction.


1992 ◽  
Vol 275 ◽  
Author(s):  
M. Narbutovskih ◽  
J. Rosner ◽  
P. Merchant ◽  
R. D. Jacowitz

ABSTRACTThis paper reports on the processes used to achieve low resistance silver contacts to YBCO thin films that have either c-axis or a-axis orientation. Characterization by x-ray diffraction and TEM verified that these films are highly oriented with either the a or the c axis oriented perpendicular to the substrate surface. TEM examination of some of the Ag/YBCO interfaces reveals the presence of an amorphous layer. We will describe the effects of ion beam etching and RTA alloying on the contact resistivity for both orientations.


1985 ◽  
Vol 51 ◽  
Author(s):  
N. Herbots ◽  
B.R. Appleton ◽  
S.J. Pennycook ◽  
T.S. Noggle ◽  
R.A. Zuhr

ABSTRACTIon beam deposition (IBD), the process whereby magnetically analyzed ions are directly deposited on single crystal substrates, has been studied for 74Ge and 30Si ions on Si(100) and Ge(100). The effects of sputtercleaning prior to deposition and substrate temperature during deposition were investigated. Three analytical techniques were systematically used to obtain information on the deposited films: (1) Rutherford backscattering combined with ion channeling, (2) cross-section TEM, and (3) Seeman-Bohlin X-ray diffraction. In the energy range explored (40–200 eV), the width of the interface between the IBD film and the substrate was found to be always less than 1 nm. Each IBD layer was highly uniform in thickness and composition for deposition temperatures from 300 K to 900 K. Without prior sputter-cleaning and annealing of the Si(100) and Ge(100) substrates, no epitaxy was observed. UHV conditions were found to be a requirement in order to grow crystalline Si films presenting bulk-like density. This was not the case for Ge films which showed bulk-like density for IBD at higher pressures. Results on the first Si/Ge superstructure grown by IBD are also shown.


2000 ◽  
Vol 647 ◽  
Author(s):  
Bernd Stritzker ◽  
Jürgen W. Gerlach ◽  
Stephan Six ◽  
Bernd Rauschenbach

AbstractIon beam assisted deposition, i.e., the bombardment of thin films with a beam of energetic particles has become a highly developed tool for the preparation of thin films. This technique provides thin films and coatings with modified microstructure and properties. In this paper examples are presented for the modifying of the structure: in-situ modification of texture during ion beam assisted film growth and ion beam enhanced epitaxy.The biaxial alignment of titanium nitride films prepared on Si(111) by nitrogen ion beam assisted deposition at room temperature was studied. The bombardment perpendicular to the surface of the substrate causes an {001} alignment of crystallites. A 55° ion beam incidence angle produces both a {111} orientation relative to the surface and a {100} orientation relative to the ion beam. This results in a totally fixed orientation of the crystallites. The texture evolution is explained by the existence of open channeling directions.Epitaxial, hexagonal gallium nitride films were grown on c-plane sapphire by low-energy nitrogen ion beam assisted deposition (≤ 25 eV). The ion energy was chosen to be less than the corrected bulk displacement energy to avoid the formation of ion-induced point defects in the bulk. The results show that GaN films with a nearly perfect {0002} texture are formed which have superior crystalline quality than films grown without ion irradiation. The mosaicity and the defect density are reduced.By applying an assisting ion beam during pulsed laser deposition of aluminum nitride on the c-plane of sapphire, epitaxial, hexagonal films could be produced. The results prove the beneficial influence of the ion beam on the crystalline quality of the films. An optimum ion energy of 500 eV was found where the medium tilt as well as the medium twist of the crystallites was minimal.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Petr Vlcak ◽  
Frantisek Cerny ◽  
Zdenek Weiss ◽  
Stanislav Danis ◽  
Josef Sepitka ◽  
...  

The ion beam assisted deposition (IBAD) method was chosen for preparing a carbon thin film with a mixing area on a substrate of Ti6Al4V titanium alloy. Nitrogen ions with energy 90 keV were used. These form a broad ion beam mixing area at the interface between the carbon film and the substrate. We investigated the chemical composition by the glow discharge optical emission spectroscopy (GD-OES) method and the phases by the X-ray diffraction (XRD) method. The measured concentration profiles indicate the mixing of the carbon film into the substrate, which may have an effect on increasing the adhesion of the deposited film. The nanohardness and the coefficient of friction were measured. We found that the modified samples had a markedly lower coefficient of friction even after damage to the carbon film, and they also had higher nanohardness than the unmodified samples. The increased nanohardness is attributed to the newly created phases that arose with ion implantation of nitrogen ions.


1990 ◽  
Vol 191 ◽  
Author(s):  
Michael E. Geusic ◽  
Alan F. Stewart ◽  
Larry R. Pederson ◽  
William J. Weber ◽  
Kenneth R. Marken ◽  
...  

ABSTRACTExcimer laser ablation with an in situ heat treatment was used to prepare high quality superconducting YBa2Cu3O7−x thin films on (100)-SrTiO3 and (100)-LaAlO3 substrates. A pulsed excimer laser (XeCl; 308 nm) was used to ablate a rotating, bulk YBa2Cu3O7−x target at a laser energy density of 2–3 J/cm2. Based on four-probe dc resistance measurements, the films exhibited superconducting transition temperatures (Tc, midpoint) of 88 and 87K with 2K (90–10%) transition widths for SrTiO3 and LaAlO3, respectively. Transport critical current densities (Jc) measured at 77K were 2 × 106 and 1 × 106 A/cm2 in zero field for SrTiO3 and LaAlO3, respectively. X-ray diffraction (XRD) analysis showed the films to be highly oriented, with the c-axis perpendicular to the substrate surface.


2002 ◽  
Vol 09 (05n06) ◽  
pp. 1611-1615 ◽  
Author(s):  
G. CAMPILLO ◽  
L. F. CASTRO ◽  
P. VIVAS ◽  
E. BACA ◽  
P. PRIETO ◽  
...  

La 0.67 Ca 0.33 MnO 3 - δ thin films were deposited using a high-pressure dc-sputtering process. Pure oxygen at a pressure of 3.8 mbar was used as sputtering gas. The films were grown on (001) LaAlO 3 and (001) SrTiO 3 substrates at heater temperature of 850° without any annealing treatment. The formation of highly a-axis-oriented films with sharp interface with substrate surface is demonstrated by X-ray diffraction, transmission electron microscope (TEM), and atomic force microscope (AFM) analysis. Electrical characterization revealed a metal–insulator transition at T MI = 276 K, and magnetic characterization showed good magnetic properties with a PM–FM transition at TC ≈ 262 K.


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