Monograph "Controlled High Fluence Ion Implantation of Materials"
Tech Area / Field
- PHY-SSP/Solid State Physics/Physics
3 Approved without Funding
Tbilisi State University (Sukhumi Branch), Georgia, Tbilisi
- SARAD GmbH/Nuclear Instruments, Germany, Dresden\nSCK-CEN, Belgium, Mol
Project summaryThe growing needs of science and technology promote the development ofr non-traditional technologies for obtaining new materials. The method of ion implantation appears to be one of the most promising of alternative science and technology methods. The advantages of ion implantation lie in obtaining new materials in conditions, which substantially differ from the traditional, and in principle possibilities to form new materials in thermodynamically non-equilibrium and metastable states.
The above and other preferable features make ion implantation one of the most important and promising means in Solid State Physics and Material Studies, and also in other fields of science and technology.
The Project offers a monograph, provisionally titled “Controlled High Fluence Ion Implantation of Mate-rials”, based on the results of many years of experience, and conducted under the scientific guidance of A. Gulda-mashvili, mainly at the unique experimental base, made under his guidance and with active participation at the Department of Ion Implantation, the Sukhumi Institute of Physics and Technology (SIPT).
Today some Internally Displaced researchers from the department are now employed at the Sukhumi branch of the I. Javakhishvili Tbilisi State University, in Tbilisi.
At the beginning of the above works, in the early 1960s, the physical basis of ion implantation had not been developed in its entirety, and was at an early stage of development. Published literature had only little and rather contradicting information on ion-implanted materials and radiation processes.
A narrow range of materials, such as semiconductors, was studied. However, separate materials and instru-ments with improved parameters were obtained by ion implantation, which were impossible to obtain using common doping methods.
A variety of phenomena, accompanying ion implantation, and the complicated dependence on parameters of ion beam and target, known limitations of a theoretical and experimental kind complicated the investigation of ion-implanted materials and stagnated the rate of their practical use. The promising potential commercial application of ion-implanted materials with improved features provided for the study of the physics of basic radiation phenomena and features of the obtained materials, developing methods, useful for studying extremely thin films and microsynthesis. One should place particular emphasis on the need to develop controlled technologies of ion implantation of materials with high fluences. Wide-ranging studies and developments of subsequent years have provided a modern level of development and commercial application of ion implantation technology.
Today, some industrially developed countries use ion implantation in semiconductor microelectronics. Com-mercial production of various semiconductor detectors of nuclear radiation, converters of solar energy into electricity, etc., is now developed. During the last decade ion implantation has found commercial application in radi-cally improving mechanical and other physico-chemical features of metals, alloys and other materials. Many industrially developed countries make items, details and tool parts, machines with increased life, designed for processing and other industries. However, in all probability, the final and comprehensive range of their commercial application is not yet determined.
Today specialists, participating in the proposed Project, have accumulated substantial data, which requires analysis, systematisation and generalisation. The proposed monograph will systematise and generalise original basic results of many years of research, conducted by A. Guldamashvili and his colleagues in the development of an experimental base for obtaining and investigating ion-implanted semiconductor and metal materials with improved parameters, and for making new kinds of various-purpose instruments and units on their basis.
Works of the Sukhumi School are known and have been recognised in scientific circles. However, due to certain circumstances wide circles of scientists at large have limited information about it, and the proposed monograph is dedicated to fill this gap. It will contain the first description of the unique experimental base of Sukhumi and will present a history of its development. The monograph will allow scientists from around the world to become familiarised with the original works of this research centre. The monograph will be written for a wide range of specialists working in the field of ion implantation. It will also be useful for specialists working in Solid State Physics, Radiation Physics, Material Studies, Semiconductor Microelectronics, Radiation Material Studies, other related fields of science and technology. Taking into account the teaching experience of the supposed Project Manager at the I. Javakhishvili Tbilisi State University and its Sukhumi Department, the monograph may be useful for students and postgraduates alike. It will comprise an introduction, five chapters, a conclusion and references. Versions of the monograph will be prepared for publishing in Georgian, English and Russian.
The importance of the objectives of the monograph is in establishing a theoretical basis of the laws and mechanisms of radiation processes of controlled improvement of the features of implanted materials and implanted-material-based instruments.
The monograph will present original results:
Units for controlled implantation of solid matter with ion isotopes of most elements of the Periodic Table and study of implanted materials by back-scattered ions are developed and designed. In terms of their specifications and application features, the units meet the requirements of the best analogues.
Features and the nature of the boron ion profile, implanted in silicon monocrystals, depending on the ion fall angle and plane and on the conditions of ion implantation are experimentally determined, theoretically based and explained. Mathematical relations for quantitative assessment of the factors, determining formation of non-channelled, de-channelled and channelled profile components, and the necessary forms of the atomic distribution complete profile are obtained. The results of the research and the proposed model can extend the range of possible application of the as yet unused advantages of channelled heavy ions in semiconductor microelectronics.
The unique features of the parameters of the distribution of implanted atoms and defects in the studied materials along the energy spectra of back-scattered ion on the matrix atoms and implanted impurities are experimentally determined and proved by calculations.
The results of the studies will be useful for developing a physical explanation of the interaction of solid matter with intensive large fluence ion flows. The results will be used for selecting the conditions of ion implantation and data interpreting.
The criteria for formation and growth of the new phase, areas of stability, features of radiation formation of thermodynamically equilibrium phases in non-equilibrium conditions of ion implantation, and its effect on the features of transit metals, are determined.
Within the ranges of the new model of various damaging ability of bombarding ions, a new view on the processes of amorphisation of semiconductors during ion implantation is developed. A common mechanism of amorphisation of the irradiated semiconductors is proposed, based on the need to accumulate a sufficient quantity of defects for transforming crystals into an amorphous state.
A new view is developed on the processes of semiconductor amorphisation during ion implantation within the range of the developed model, various abilities of bombarding ions and changes in the target composition and defect ability. A general mechanism and criteria of amorphisation of semiconductors, irradiated with any partic-les will be offered.
Criteria of simulation of degradation parameters of irradiated boron-containing materials with ion bombardment are determined for the first time. The results of boron carbide irradiation with the ions of the target proper and with the ions of decay products of neutron absorbing boron nuclides, -particles and lithium particles have been obtained for the first time. The obtained results will allow one to predict the degradation level in nuclear reactors and boron carbide parameters with varied content of neutron absorbing boron nuclides, and to optimise the process of obtaining boron carbide and the capacity of control systems and alarm control and protection systems in nuclear reactors, made of boron carbide.
Using preferential features of controlled high fluence ion implantation:
High strength nitride, carbide, and silicide compounds of transit metals have been synthesised for the first time in the temperature and concentration ranges, in which their formation has not been observed without ion bombardment;
Boron, nitrogen, carbon and other ion-implanted materials of transitive metals with precisely wide-range controlled improved strength, emission-adsorption and super-conductive features have been obtained for the first time. A substantial increase in hardness and wear resistance of the electronic work function of the surface layers of ion implanted transit metals, preserving the plastic features of the rest bulk, has been achieved for the first time.
Promising application of implanted refractory metals with high emission-adsorption features for collector metals of thermal emission converters (TEC) of thermal energy into electricity was shown for the first time. A substantial rise in output electric parameters of experimental TEC, accompanied by the preservation of common construction and production technology of electrodes, and TEC as a whole, was achieved for the first time.
An original compact detector with p-n junction has been developed for the first time; its inversion layer with hole conduction, combined with the converter of neutron absorbers is provided by implanting absorbing nuclides and boron-10 isotopes, and the efficacy of module recording equals 10%. The specifications of the above detector are much better than those of existing common semiconductor detectors of thermal neutrons.
Obtained implanted electrodes are able to contribute to the development of improved TEC of a new generation with high electric parameters. Developed implantation materials with precisely controlled emission-adsorption features can also be used in solid state electronics and electrotechnical instrumentation engineering.
The developed ion-implanted semiconductor detector of thermal neutrons (IISTND) can contribute to the solution to problems of environment protection, safety of nuclear reactors, geology, medicine and other fields, and it is recommended for commercial production.
The results of studies of structural and phase transformations and their effect on macroscopic features of materials may be used in developing general industrial technology of production of radiation-modified materials with improved strength, emission, adsorption, super-conduction and other features.
The results may be applied in developing scientific bases of implantation metallurgy, radiation technology of processing metal and alloy surfaces by bombardment with accelerated ion beams.
The results may also be useful for understanding and predicting the degradation of macroscopic features of materials in nuclear and thermo-nuclear reactors and other irradiated materials.
The proposed mechanisms of phenomena, taking place during ion implantation are considered as the development of general views of the physics of solid state and can form the basis for solving urgent problems of solid state radiation physics, radiation material study and radiation technology.
The scientific usefulness of the monograph provides for the scientific grounding and further improvement of the method of ion implantation, development of physical presentation on the processes, observed in the conditions of high fluence controlled ion implantation of materials, and extension of the field of application of ion implantation technology.
Specialists, participating in the Project have accumulated experience in developing an experimental base for ion implantation, in obtaining implantation materials, instruments and units designed for various purposes, for nuclear science and technology, for semiconductor microelectronics, electronics of solid state and other fields of science and technology.
The problems, to be solved in the proposed Project, comply with the objectives and tasks of the ISTC on employment of weapons specialists in developing alternative ion implanted materials and instruments for peaceful application, on supporting research and development works, promoting the solution of national and international technical problems and co-operation of scientists in the international scientific community.
Co-operation with foreign collaborators is planned to involve exchange of scientific information, commentaries on annual and final technical reports, assistance in attending international conferences and the organisation of joint workshops.
The monograph is also to include a summary and development of earlier proposed theoretical models and improvement of calculation methods. The results analysis and summing up will be conducted taking into account the latest scientific achievements. References with abstracts from literature, published during recent years are to be presented, and references are to be made available through the Internet. Also, the work includes subscription to international scientific periodicals and monographs.
The Project manager has been lecturing at the Physics department of the I. Javakhishvili Tbilisi State University and its Sukhumi Department for several years, using the materials, to be used in the monograph.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.