The Chemical Vapor Deposoitin of Pure Nickel and Nickel Boride Thin Films from Borane Cluster Compounds

1991 ◽  
Vol 250 ◽  
Author(s):  
Shreyas Kher ◽  
James T. Spencer

AbstractSeveral borane cluster compounds, such as pentaborane(9) and their corresponding metal complexes have been investigated in our laboratory for their utility as unique source materials for synthesizing metal/metal boride thin films by MOCVD. In this paper we report the preparation of thin films of nickel boride from the thermal decomposition of nido- pentaborane( 9) in the presence of anhydrous nickel chloride [NiCl2] in the vapor phase. Crystalline nickel boride thin films of controlled composition ranging from 0.1 to several microns have been readily prepared by controlling the temperature and the flow rate of the pentaborane(9) into the reaction chamber. The nickel boride films on GaAs were thermally annealed to form the Ni7B3 phase as hexagonal crystals in a Ni3B matrix. These films have been characterized by AA, AES, EDXA, SEM, XRD and electron diffraction. The phases were determined primarily by X-ray and electron diffraction experiments.

1990 ◽  
Vol 204 ◽  
Author(s):  
John A. Glass ◽  
Shreyas Kher ◽  
Stephen D. Hersee ◽  
G. Ramseyer ◽  
James T. Spencer

ABSTRACTThe preparation of aluminum-containing thin film materials by MOCVD and MOMBE for use in III-V semiconductor materials, such as HEMT devices, is currently under active investigation. The preparation of uniform, conformal aluminum and boron containing thin film materials from the chemical vapor deposition (CVD) of aluminum borane cluster precursor compounds has been studied. A variety of substrates, deposition conditions and aluminaborane precursors have been explored and their effect on film composition, growth rate and thin film morphology has been investigated. The thermal depositions of aluminum and boron-containing thin films from aluminum borohydride, AI(BH4)3, on copper, SiO2 and GaAs are reported. Boron incorporation in the films vary depending on substrate temperature, aluminaborane flow and the presence or absence of a H2 carrier. These films have been characterized by SEM, AES and XES.


1990 ◽  
Vol 204 ◽  
Author(s):  
John A. Glass ◽  
Shreyas Kher ◽  
Yoon-Gi Kim ◽  
P.A. Dowben ◽  
James T. Spencer

ABSTRACTThe deposition of high purity and controlled stoichiometry metal boride thin-film materials has recently received considerable interest. Borane clusters and their corresponding metal complexes are currently being investigated in our laboratories for their utility as unique source materials for the formation of metallic boride thin films by MOCVD. Variable composition nickel boride thin films ranging from 0.1 micron to several microns have been prepared. These new materials have been characterized by SEM, AES and XES. The magnetic properties of these new films have been investigated with torque magnetometry and magneto-optic Kerr effect magnetometry.


1988 ◽  
Vol 131 ◽  
Author(s):  
Zhongju Zhang ◽  
Yoon-Gi Kim ◽  
P. A. Dowben ◽  
James T. Spencer

ABSTRACTNew borane clusters and their corresponding transition and rare earth metal complexes are currently being investigated in our laboratories for their utility as unique source materials for the formation of both metallic and non-metallic thin films. These borane cluster complexes exhibit highly favorable properties for use in OMVPE processes, such as; (1) relatively high volatility, (2) anticipated high stability of the ligand itself to provide clean ligand-metal dissociations, (3) high temperature stabilities of the complexes, (4) readily preparable in significant quantities, and (5) availability of theoretical and spectroscopic probes of structure-reactivity relationships. In this work, we have prepared both non-metallic thin films, including materials such as boron nitride, and metallic thin films (both the transition and rare earth metals) through the use of these unique cluster materials.Boron nitride has been investigated as a potential hard coating for use as an insulating electrical layer and protective coating. We have investigated plasma enhanced chemical vapor deposition and pyrolytic deposition of boron nitride from readily available and easily handled borane clusters. Auger electron spectroscopy was used to show that the film was high purity boron nitride of uniform composition.The deposition of transition and rare earth metal thin-film materials of controlled stoichiometry has recently received considerable interest. We have discovered the borane cluster-assisted deposition (CAD) of metallic thin-films involving both transition and rare earth metal materials. Through the use of this unprecedented borane cluster chemical transport process, films ranging in thickness from 100 nm to several microns have been straightforwardly and systematically prepared for numerous metal and mixed-metal boroncontaining systems with controlled composition at relatively low temperatures. These new materials have been characterized by SEM and other techniques.


1994 ◽  
Vol 361 ◽  
Author(s):  
D.L. Kaiser ◽  
M.D. Vaudin ◽  
L.D. Rotter ◽  
Z.L. Wang ◽  
J.P. Cline ◽  
...  

ABSTRACTMetalorganic chemical vapor deposition (MOCVD) was used to deposit epitaxial BaTiO3 thin films on (100) MgO substrates at 600°C. The metalorganic precursors employed in the deposition experiments were hydrated Ba(thd)2 (thd = C11H19O2) and titanium isopropoxide. The films were analyzed by means of transmittance spectroscopy, wavelength dispersive x-ray spectrometry, secondary ion mass spectrometry depth profiling, x-ray diffraction, high resolution transmission electron microscopy, selected area electron diffraction, nanoscale energy dispersive x-ray spectrometry and second harmonic generation measurements. There was no evidence for interdiffusion between the film and substrate. The x-ray and electron diffraction studies showed that the films were oriented with the a-axis normal to the substrate surface, whereas second harmonic generation measurements showed that the films had some c-axis character.


1994 ◽  
Vol 9 (2) ◽  
pp. 426-430 ◽  
Author(s):  
V.P. Dravid ◽  
H. Zhang ◽  
L.A. Wills ◽  
B.W. Wessels

Thin films of BaTiO3 deposited on (100)LaAlO3 substrate by metal-organic chemical vapor deposition (MOCVD) are investigated using several electron-optical techniques. Combined high resolution transmission electron microscopy (HRTEM), electron energy loss spectrometry (EELS), and convergent beam electron diffraction (CBED) indicate a substantial influence of lattice strain on the structural and optical characteristics of BaTiO3 films. Spatially resolved EELS and CBED studies indicate that the substrate influence persists up to about 40 nm away from the interface. The changes in the dielectric function of the films, as inferred from spatially resolved EELS, appear to correlate well with internal lattice strain in the films as deduced from convergent beam electron diffraction (CBED).


2001 ◽  
Vol 672 ◽  
Author(s):  
Sang Y. Kang ◽  
Cheol S. Hwang ◽  
Hyeong J. Kim

ABSTRACTRu thin films were deposited on SiO2/Si and (Ba,Sr)TiO3 [BST]/Pt/TiO2/SiO2/Si substrates using Ru(C2H5C5H4)2 [Ru(EtCp)2] by metal-organic chemical vapor deposition (MOCVD). To determine the effects of the solvent, C4H8O [tetrahydrofuran: THF], it was injected into the reaction chamber by the Direct Liquid Injection (DLI) system while Ru(EtCp)2 was input through the bubbler system. Also, Ru thin films were deposited using a liquid source, Ru(EtCp)2 dissolved in THF, delivered by the DLI system. The surface of the Ru thin films deposited on the BST substrate using only Ru(EtCp)2 through the bubbler system was very rough and milky, but the addition of THF made the surface of the films smooth and clean. In addition, Ru films deposited at 325°C using Ru(EtCp)2 dissolved in THF through the DLI system have a dense and smooth microstructure with resistivity as low as 15µωcm.


Author(s):  
Karren L. More

Beta-SiC is an ideal candidate material for use in semiconductor device applications. Currently, monocrystalline β-SiC thin films are epitaxially grown on {100} Si substrates by chemical vapor deposition (CVD). These films, however, contain a high density of defects such as stacking faults, microtwins, and antiphase boundaries (APBs) as a result of the 20% lattice mismatch across the growth interface and an 8% difference in thermal expansion coefficients between Si and SiC. An ideal substrate material for the growth of β-SiC is α-SiC. Unfortunately, high purity, bulk α-SiC single crystals are very difficult to grow. The major source of SiC suitable for use as a substrate material is the random growth of {0001} 6H α-SiC crystals in an Acheson furnace used to make SiC grit for abrasive applications. To prepare clean, atomically smooth surfaces, the substrates are oxidized at 1473 K in flowing 02 for 1.5 h which removes ∽50 nm of the as-grown surface. The natural {0001} surface can terminate as either a Si (0001) layer or as a C (0001) layer.


Author(s):  
R. H. Geiss

The theory and practical limitations of micro area scanning transmission electron diffraction (MASTED) will be presented. It has been demonstrated that MASTED patterns of metallic thin films from areas as small as 30 Åin diameter may be obtained with the standard STEM unit available for the Philips 301 TEM. The key to the successful application of MASTED to very small area diffraction is the proper use of the electron optics of the STEM unit. First the objective lens current must be adjusted such that the image of the C2 aperture is quasi-stationary under the action of the rocking beam (obtained with 40-80-160 SEM settings of the P301). Second, the sample must be elevated to coincide with the C2 aperture image and its image also be quasi-stationary. This sample height adjustment must be entirely mechanical after the objective lens current has been fixed in the first step.


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