Elements Of X Ray Diffraction

Methods are provided herein for treating substrate surfaces in preparation for subsequent nucleation-sensitive depositions (e.g., polysilicon or poly-SiGe) and adsorption-driven deposition (e.g. atomic layer deposition or ALD). Prior to depositing, the surface is treated with non-depositing plasma products. The treated surface more readily nucleates polysilicon and poly-SiGe (such as for a gate electrode), or more readily adsorbs ALD reactants (such as for a gate dielectric). The surface treatment provides surface moieties more readily susceptible to a subsequent deposition reaction, or more readily susceptible to further surface treatment prior to deposition. By changing the surface termination of the substrate with a low temperature radical treatment, subsequent deposition is advantageously facilitated without depositing a layer of any appreciable thickness and without significantly affecting the bulk properties of the underlying material. Preferably less than 10 Å of the bulk material incorporates the excited species, which can include fluorine, chlorine and particularly nitrogen excited species.

Surface preparation prior to deposition

Embodiments of a gas diffuser plate for distributing gas in a processing chamber are provided. The gas distribution plate includes a diffuser plate having an upstream side and a downstream side, and a plurality of gas passages passing between the upstream and downstream sides of the diffuser plate. The gas passages include hollow cathode cavities at the downstream side to enhance plasma ionization. The depths, the diameters, the surface area and density of hollow cathode cavities of the gas passages that extend to the downstream end can be gradually increased from the center to the edge of the diffuser plate to improve the film thickness and property uniformity across the substrate. The increasing diameters, depths and surface areas from the center to the edge of the diffuser plate can be created by bending the diffuser plate toward downstream side, followed by machining out the convex downstream side. Bending the diffuser plate can be accomplished by a thermal process or a vacuum process. The increasing diameters, depths and surface areas from the center to the edge of the diffuser plate can also be created computer numerically controlled machining. Diffuser plates with gradually increasing diameters, depths and surface areas of the hollow cathode cavities from the center to the edge of the diffuser plate have been shown to produce improved uniformities of film thickness and film properties.

Plasma uniformity control by gas diffuser hole design

A high k dielectric film and methods for forming the same are disclosed. The high k material includes two peaks of impurity concentration, particularly nitrogen, such as at a lower interface and upper interface, making the layer particularly suitable for transistor gate dielectric applications. The methods of formation include low temperature processes, particularly CVD using a remote plasma generator and atomic layer deposition using selective incorporation of nitrogen in the cyclic process. Advantageously, nitrogen levels are tailored during the deposition process and temperatures are low enough to avoid interdiffusion and allow maintenance of the desired impurity profile.

Incorporation of nitrogen into high k dielectric film

The generalization of the Local Density Approximation (LDA) method for the systems with strong Coulomb correlations is presented which gives a correct description of the Mott insulators. The LDA+U method is based on the model hamiltonian approach and allows to take into account the non-sphericity of the Coulomb and exchange interactions. parameters. Orbital-dependent LDA+U potential gives correct orbital polarization and corresponding Jahn-Teller distortion. To calculate the spectra of the strongly correlated systems the impurity Anderson model should be solved with a many-electron trial wave function. All parameters of the many-electron hamiltonian are taken from LDA+U calculations. The method was applied to NiO and has shown good agreement with experimental photoemission spectra and with the oxygen Kα X-ray emission spectrum.

http://absimage.aps.org/image/MAR06/MWS_MAR06-2005-007233.pdf

First-principles calculations of electronic structure and spectra of strongly correlated systems: the LDA+U method

Pulse enhanced electron emission (P3e (TM)) is a new approach in PVD technology for the deposition of metal oxides. The process is dedicated to the formation of alumina-based and other metallic oxide layers and comprises high current pulse technique for the arc sources. The method allows a deposition of hard alumina-based coatings at substrate temperatures below 600 degrees C. Different oxide layers and layer combinations were prepared with this new technique illustrating the enormous potential for the design of wear resistant coatings. The layers were characterized with respect to hardness, stress, composition, crystal structure, and thermal stability. Solid solutions of (Al1-xCrx)(2)O-3 could be synthesized for a composition range of 0.3 <= 5x<l. The growth of the solid solutions has also been demonstrated at TiCN and TiAlN interfaces. (c) 2007 Elsevier B.V. All rights reserved.

Pulse enhanced electron emission (P3e™) arc evaporation and the synthesis of wear resistant Al–Cr–O coatings in corundum structure

The plasma chemical cleaning process based on an argon-hydrogen discharge differs from conventional plasma cleaning methods. Chemical reactions are used for the removal of surface contamination and the sputtering of material is avoided. Therefore no problems due to the redeposition of the sputtered material occur. The process chemistry is confirmed by in situ measurements of the plasma during the cleaning procedure using a plasma monitor. The process was investigated for bare copper lead frames and for silicon wafers. Volatile hydrogen compounds were formed during cleaning. An Auger spectrometer was attached to the cleaning chamber to investigate the substrate surfaces after each cleaning step. It was shown that the carbon and oxygen contamination at the substrate surface could be reduced below 0.5 at.% (noise limit of the measurement). The results clearly show that this simple and environmentally friendly process is an effective method for reducing organic and some inorganic contamination.

Hydrogen plasma chemical cleaning of metallic substrates and silicon wafers

The present work investigates the microstructure and chemical composition of macroparticles incorporated in arc evaporated (Al,Cr)2O3 coatings. According to scanning and transmission electron microscopy analysis, two different types of macroparticles with a distinct difference in their shape and a noticeable variation in their chemical composition, i.e. the Al/Cr ratio, can be distinguished. In addition, the transformations on the surface of the corresponding Al–Cr compound cathodes during the evaporation process in O2 atmosphere are studied by scanning electron microscopy and X-ray diffraction. Beside the virgin cathode material, a reaction layer consisting of various intermetallic AlxCry phases with a fine-grained morphology and pillar-shaped Al2O3 islands was found. Correlations between the origin of the macroparticles and the observed modifications at the surface of the Al–Cr cathode are discussed.

Cathodic arc deposition of (Al,Cr)2O3: Macroparticles and cathode surface modifications

A novel cathodic arc evaporation process operated in pure oxygen forms corundum-type micro-crystalline structures at temperatures below 600°C. Thermally stable crystalline solid solutions of corundum-type (Al 1-xCrx)2Oy have been prepared with this method for x ≥ 0.3 at non-equilibrium conditions. The stability in (Al,Cr)2O3 phases can be explained by their degree of crystallinity and ordering within the structure. The applied processing method results in highly crystalline coatings of pure α-(Al1-xCr x)2Oy. With increasing fabrication temperature (maximum 600°), more stable phases are obtained showing no metal site splitting in the atomic structure. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA,.

Thermal Stability of Thin Film Corundum‐Type Solid Solutions of (Al1–xCrx)2O3 Synthesized Under Low‐Temperature Non‐Equilibrium Conditions

Thin Al–Cr–O films are proposed as hydrogen permeation barriers. Layers of a few microns in thickness are able to suppress hydrogen permeability by a factor of 2000 to 3500 at temperatures of 700 °C, as has been found in our gas phase permeation experiments. We attribute this excellent efficiency to a dense layer morphology and the possible (pre)-formation of solid solutions in corundum-type structure. These films are deposited by pulsed arc evaporation in a batch-type production system at substrate temperatures of 550 °C.

Jürgen Ramm

Papers

Pulse enhanced electron emission (P3e™) arc evaporation and the synthesis of wear resistant Al–Cr–O coatings in corundum structure

Hydrogen plasma chemical cleaning of metallic substrates and silicon wafers

Cathodic arc deposition of (Al,Cr)2O3: Macroparticles and cathode surface modifications

Thermal Stability of Thin Film Corundum‐Type Solid Solutions of (Al1–xCrx)2O3 Synthesized Under Low‐Temperature Non‐Equilibrium Conditions

Al-Cr-O thin films as an efficient hydrogen barrier