A. M. Badalyan

Plasma-Enhanced Chemical Vapor Deposition of Silicon Carbonitride Films from Volatile Silyl Derivatives of 1,1-Dimethylhydrazine

Silicon carbonitride films were synthesized from new volatile precursors by plasma-enhanced chemical vapor deposition. Based on a detailed study of the morphology of film surfaces, it was found that the layer material was an amorphous matrix with inclusions of nanosized crystals. Calculation of the structure of the crystalline phase from synchrotron X-ray diffraction patterns demonstrated that the entire set of the diffraction peaks detected is indexed by a tetragonal structure with the lattice parameters a = 9.6 Å and c = 6.4 Å. This is consistent with the fact that the carbon 1s and nitrogen 1s core level X-ray photoelectron spectra exhibited only sp3 bonding, which was expected for superhard carbon nitride phases.

Microstructure and Chemical Bonding in Silicon Carbonitride Films Synthesized by Plasma Enhanced Chemical Vapor Deposition

Silicon carbonitride films were synthesized by plasma enhanced chemical vapor deposition using silyl derivatives of asymmetric dimethylhydrazine, (CH3)2HSiNHN(CH3)2 and (CH3)2Si[NHN(CH3)2]2, as molecular precursors. The film material consists of an amorphous matrix with nanocrystalline inclusions. Indexing of synchrotron radiation X‐ray diffraction patterns suggests that the structure of the nanocrystals is tetragonal with lattice parameters a = 9.6Å and c = 6.4Å. X‐ray photoelectron spectra indicate that Si—N and C—N sp3 hybrid bonds are predominant. The absence of G‐ or D‐modes in Raman spectra, which are otherwise typical of structures possessing sp2 bonding, provides further support for the tetragonal structure of the nanocrystals.

New technique for heterogeneous vapor-phase synthesis of nanostructured metal layers from low-dimensional volatile metal complexes

A new technique for depositing thin nanostructured layers on semiconductor and insulating substrates that is based on heterogeneous gas-phase synthesis from low-dimensional volatile metal complexes is suggested and tried out. Thin nanostructured copper layers are deposited on silicon and quartz substrates from low-dimensional formate complexes using a combined synthesis-mass transport process. It is found that copper in layers thus deposited is largely in a metal state (Cu0) and has the form of closely packed nanograins with a characteristic structure.

Plasma electroradiolysis of aqueous solutions

Electroradiolysis of aqueous solutions, a process that is induced by the action of glow discharge on an electrolytic cathode, is considered. The results of investigation of systems of this type are summarized. The set of phenomena at the discharge plasma/electrolyte-cathode interface is treated in terms of radiation chemistry, plasma chemistry, emission electronics, and gas discharge physics. A new area of research, electroradiation chemistry of water and aqueous solutions, is presented.

Composition and Structure of Films Deposited from Silyl Derivatives of Asymmetrical Dimethylhydrazine

Si–N–C films were produced by remote-plasma chemical vapor deposition using silyl derivatives of asymmetrical dimethylhydrazine as precursors and were characterized by optical spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, and synchrotron x-ray diffraction. The results demonstrate that Si–N and Si–C bonds prevail in the films deposited using excited hydrogen, while the structure of the films deposited using excited helium is dominated by Si–N and C–N bonds. The films contain both amorphous and crystalline silicon carbonitride. The crystalline phase can be indexed in a tetragonal cell with lattice parameters a= 9.6 Å and c= 6.4 Å. The formation of the crystalline phase and the shape of the crystallites are not correlated with the deposition temperature, which gives grounds to believe that the crystallization process may occur in the gas phase or on the film surface as a result of the increase in mechanical stress with increasing film thickness.

Formation of small volatile complexes during copper film growth by the combined synthesis-transport method

Stable heterogeneous synthesis products in combined synthesis-transport processes for the growth of thin copper films have been studied by ESR, X-ray photoelectron, and IR spectroscopies. The results demonstrate that the synthesized volatile compounds condensed on solid surfaces have the form of formate-like metal complexes of copper(I). We have identified the mechanisms underlying the formation of volatile monomeric metal complexes on the surface of copper-containing precursor particles and the mechanism of the thermal decomposition of metal complexes on a heated substrate.

Formation of thin nanostructured layers during heterogeneous gas-phase synthesis from small-size volatile metal complexes on the surface of semiconductors and dielectrics

We have developed and verified a new method for the formation of thin nanostructured layers on semiconductor and dielectric substrates by heterogeneous gas-phase synthesis from small-sized volatile metal complexes. Thin nanostructured layers of copper on silicon and silica substrates were successfully formed from small-sized volatile formiate metal complexes using a combined synthesis-transfer process. It is established that copper in the layers deposited by this method predominantly occurs in the metallic (Cu0) state in nanosized grains with a characteristic close-packed structure.

A Novel Plasma-Chemical Process of Metallic Layer Deposition From Small-Size Volatile Metal Complexes

Metallic copper ultra-thin layers were synthesized by modified PE CVD method from low-sized volatile metal complexes consisting of small (2- to 5atomic) ligand molecules. To characterize the deposited copper layers the X-ray photoelectron (XPS), infrared (FTIR) and UV-vis spectroscopy, SEM, XRD analyses were used. The layers were found to be nanocrystalline and have a nanoscale grain structure with parameters depending on the experimental conditions. It was revealed that plasma activation decreases mean size of copper grains and increases its stability on the air. The microstructure of the layers was examined by scanning electron microscopy (SEM) and diffraction of synchrotron radiation (DSR) methods, and chemical composition with a predominant content of copper in the metallic state Cu0.

On the mechanism of remote plasma-enhanced chemical vapor deposition of films

332 As we showed earlier [1], the remote plasmaenhanced chemical vapor deposition (RPE-CVD) process used for film fabrication makes it possible to preserve intact fragments of a precursor molecule that are required to synthesize the desired material. Despite close attention given by researchers to such processes, most works in this field deal with the study of the dependence of the properties of the film material on the synthesis conditions, while the mechanism of plasmaassisted activation of precursor molecules remains beyond the area of experimental interest [2–4].