Modification and Metallization of Bulk Materials and Particles
Development of Competitive Technologies for Modification and Metallization of Bulk Materials and Powder-Like Particles for Obtaining Specially Desired Properties
Tech Area / Field
- MAN-MAT/Engineering Materials/Manufacturing Technology
8 Project completed
Senior Project Manager
Genisaretskaya S V
Georgian Academy of Sciences / Institute of Physics (Ge), Georgia, Tbilisi
- University of Tokyo, Japan, Tokyo\nFraunhofer Institute Zuverlassigkeit und Mikrointegation, Germany, Berlin\nUS Department of Commerce / National Institute of Standards and Technology, USA, MD, Gaithersburg\nBroddarp, USA, NV, Henderson\nTexas A&M University / Thin Film Microelectronics Research Laboratory, USA, TX, College Station\nGeorgia Institute of Technology / W. Woodruff School of Mechanical Engineering, USA, GA, Atlanta
Project summarySurface treatment and metallization, deposition of wear- and corrosion-resistant and functional coatings, in particular deposition of Au and Ag, are carried out either by means of high-temperature long-time fusing of silver-containing pastes or by vacuum metallization, steam-gas plating, electroplating, electroless metallization with preliminary activation with noble metals salts, etc.
The problems of the existing metallization methods are: high consumption and loss of precious metals; a long time required for fabrication of devices; complexity and expensiveness of the equipment for vacuum deposition or steam-gas metallization; high energy consumption; difficulties in obtaining coatings of uniform thickness on complex-shaped devices; in some cases, an impossibility of plating the inner difficult-to-reach surfaces, especially inner surfaces of small hollow devices and pipes; difficulties in continuous metallization of three-dimensional devices and structures, in alloy deposition of the given chemical and phase compositions and the specified structure; in some cases, a necessity in usage of toxic and carcinogenic substances; complexity of obtaining thin, pore-free or thick films with low internal stresses and high adhesion to the polished surfaces of dielectrics and semiconductors, etc. Only the US electronic industry consumes several tens of tons of gold annually.
As a result of the Project implementation, all the abovementioned problems will be overcome.
Relevant prior work carried out by the Project participants.
The methods of metallization and surface treatment of various materials developed under the leadership of Prof. T. Khoperia were widely implemented in mass production in defense industry in the fields of space engineering; remote fuses; antimissile units; hydroacoustic devices for submarines and ships; transportation devices of mass destruction weapons; microelectronics; piezoengineering and computing engineering for production of photomasks, ICs, quartz resonators and filters, monolithic piezoquartz filters, piezoceramic products for delay lines of color TV sets and hydroacoustics, resistors, aircraft gyroscopes, etc. The abovementioned technologies will be significantly improved as a result of the Project implementation. Application of the Project results in manufacture of civil products will be very promising.
The objectives of the Project.
The objective of this Project is to develop new competitive technologies which will allow: to exclude the drawbacks of the surface treatment and metallization methods having existed so far; to vary the physical and chemical properties of the coatings in the wide range; to produce films with the prescribed properties; to substitute adequately precious metals with non-precious ones, and to exclude the usage of toxic and carcinogenic substances. One of the objectives of the Project is to propose a reliable method of micro and nanominiaturization of electronic devices. The next objective of the Project is the development of new competitive technologies for fabricating heterostructures and nanometer-scale layers with unusual properties. The other objective is the development of the method of obtaining ultra-thin void-free and pore-free coatings with the specified properties on micro- and nanosized particles.
At electroless deposition on polished surfaces of dielectrics and semiconductors, some difficulties arise from the viewpoint of high coverage by metals and obtaining the continuous pore-free thin films with high adhesion strength. The metallization of smooth piezomaterials, glass is carried out by means of labour-intensive and expensive processes of silver and gold plating by vacuum-thermal evaporation or fusing an Ag-containing paste. Replacement of these processes by a more simple and cheap method of metallization of polished surfaces is of current concern. Fulfillment of this task is one of the objectives of the present Project.
The scientists and specialists employed in the defense industry will be engaged in alternative
activities – development of new technologies and designs for producing sensors; devices of piezoceramic delay lines and filters for color televisions including the filters functioning on the basis of surface-acoustic waves; quartz resonators for electronic clocks; monolithic piezofilters; heads for record player transducers, video equipment, tape recorders and radiotelephones; high-quality adsorbents; catalysts; igniters for heating devices; high-strength metals; composite materials; materials for capturing toxic substances and cleaning the environment, and other civil products.
Expected results and their implementation.
The pretreatment of various materials prior to metallization (sensitization, activation); the composition of solutions and the parameters of electroless and electrochemical deposition; the conditions of photolithography, selective etching and thermal treating processes, etc. will be improved. This will exclude many drawbacks of the existing technological processes. To produce films with the specified properties (both on bulk materials and powder-like particles, carbides, nitrides, borides, oxides, zeolites, etc.), the influence of different factors such as temperature, concentration, pH, additives, surface roughness, etc. on sensitization, activation and electroless deposition will be investigated.
The activation mechanism of non-metallic materials will be established; the metallization process of the inner difficult-to-reach surfaces of narrow hollow units will be developed; the time of the metallization process will be reduced by a factor of 10; the power consumption and labor intensity will be significantly decreased; the usage of noble metals and toxic substances will be excluded. A new method of electroless metallization of dielectrics and plastics and powder-like particles without activation by noble metals will be developed.
The developed methods will enable us to produce both local and continuous pore-free thin and thick coatings of uniform thickness having low internal stress and high adhesion on arbitrary shaped non-organic dielectrics, plastics and semiconductors. The coatings adhesion to any surface roughness including polished surfaces will be high. In some cases, adhesion will exceed cohesion even of the quartz.
One should also note the possibility of obtaining hexavalent chromium-free hard coatings. This possibility is very important for ecology, as over the last 10 years hexavalent chromium has been recognized as highly toxic and carcinogenic. The proposed coatings will provide high microhardness, corrosion- and wear resistance, and temperature and radiation stability. Uniformity of these coatings on complex-shaped devices will be significantly higher as compared to hard chromium. The coatings proposed in the Project will have a low friction coefficient, high microhardness, optimum ductility and excellent tribological properties. Owing to these advantages, many problems of the wear resistance increase can be overcome, especially when liquid lubricants are not used, e.g. in space techniques, in ultra-high vacuum, at high temperature, etc.
Void-free and pore-free thin coatings having high adhesion to both the bulk materials and powder-like particles (carbides, borides, nitrides, oxides) will be obtained. The method will allow us to vary the electrical resistance and melting point of the coatings in the wide range. This point is very important for powder metallurgy; for increasing the toughness of metals (having high or low electrical resistance and melting points), ceramics and other dielectrics; ecology (in the case of obtaining high-quality adsorbents); civil nuclear techniques (at obtaining getters for ultra-high vacuum); electric-vacuum devices; composites fabrication; power electronics; microelectronics; photonics; machine building, etc.
The great importance of deposition of void-free and pore-free films on the particles by the proposed electroless method is emphasized also by the fact that the theoretical strength of metals and alloys exceeds the strength obtained in practice 100 or even 1,000 times. Inclusion of the metallized particles into metals, alloys, ceramics or plastics can significantly increase their strength, microhardness, wear resistance, tribological properties, and temperature and radiation stability. The coatings (on powder-like nanosized particles) with the specified catalytic activity and very large surface area can be used for capturing toxic gases, cleaning the environment, and for reproduction of useful bacteria (for example, in pharmacology) for detoxification of heavy metals and metalloids.
The abovementioned predetermined properties of metallized micro- and nanosized particles provide great possibilities for their application in a biomedical field, in medical practice, for purification of blood, etc. The proposed methods can be applied for safe transportation and abolition
The developed technologies will significantly expand the function of the devices made of ceramics, quartz, glass, semiconductors, plastics, metals and other materials.
The technologies of modification of various materials will permit to produce: high-quality adsorbents; catalysts; powder-like metallized particles; piezorezonators and piezofilters; piezoceramic devices; photomasks, sensors, etc. for civil products; Al memory disks; current-conducting lines and film resistors (on the surfaces of dielectrics, semiconductors and plastics); ohmic contacts; diffusion barrier layers of integrated circuits; vacuum-tight soldering; screens for shielding electronic devices and protecting people and environment against electromagnetic interference (only for shielding of electronic devices more than $ 200 million were spent in the USA); glasses for multicolor illumination (significantly more effective than the neon illumination) of streets, facades, interiors, shop windows, etc. These illumination glasses will operate both being lighted by a lamp and without electric power.
Both a new competitive technology and a new unique design of a two-layer photomask with semitransparent masking elements will be developed by means of conventional single photolithography. The developed method will enable us to solve one of the main problems in modern microelectronics.
Application of the of the Project results can solve some of the most challenging problems of microelectronics, optoelectronics, photonics and materials research. The next generation of microdevices and nanostructures will be obtained by the developed methods. The proposed methods will allow us to obtain nanometer-scale layers (having the properties very different from those of bulk materials) with unusual electrical, optical, magnetic and mechanical properties and uniform thickness on arbitrary-shaped substrates.
An electroless copper deposition technology using non-toxic substances as reducing agents replacing toxic formaldehyde will be developed. The solution will function at lower pH than the conventional solutions of electroless copper deposition. This will prevent the dissolution of a photoresist and many substrates, i.e. will exclude the drawbacks of the existing methods.
One of the results of the Project will be the development of the technology of metal film electroless deposition with the specified properties on the inner surface of the ceramic vacuum chamber of an electron synchrotron. This will allow to remove a static charge and simultaneously to obtain the given values of eddy (Foucault) currents. This will permit the scientists involved in the production of nuclear weapons of mass destruction to be alternatively engaged in fundamental investigations in the civil field.
The mechanism and reaction kinetics as well as the film structure will be investigated. The samples will be prepared and tested. The monograph on the subject of the Project will be prepared for publication and the application for patenting will be worked out. The possibility of using the developed competitive technologies in mass production in civil fields will be achieved. The data for a business plan will be elaborated. The prospects for organizing a joint venture will be created. The technological charts will be elaborated for realization of the Project results.
Nineteen scientists and specialists, earlier been engaged in developing weapons for spacecraft, submarines, microelectronics, nuclear technique and other military equipment, participate in the Project. The proposed Project will enable them to reorient their abilities to peaceful activities.
The term of the Project is 3 years. The amount of effort envisages three major interconnected tasks. The role of foreign collaborators consists in discussing the Project results, testing the samples, assisting in realization of the results, exchanging the information, promoting the publications and patenting.