Final Report Summary - MASTIC (Multi Atomistic Monte Carlo Simulation of Technologically Important Crystals)
In the one hand, ion implantation is still the main technology used for doping silicon-based wafers in the microelectronics industry. In order to continue with the size reduction of transistors it is necessary to use complex implantation conditions such as amorphizing implants. Models predicting the resulting dopant profile reduce significantly the number of experiments necessary to design the best process to obtain the desired properties. On the other hand, in the case of development of materials for fusion energy applications, models are crucial since, as of today, there are no experimental facilities to reproduce the same conditions that the materials will withstand in a fusion reactor. Therefore, extrapolations must be made from different irradiation conditions, such as those achieved in fission reactors or under ion implantation. Although these multiple materials and their applications are different, the basic mechanisms are the same: production of defects, diffusion of these defects and interaction with other defects, impurities or the material microstructure (grain boundary, dislocations, etc). In the case of microelectronics these effects must be followed for a time scale of minutes, while in fusion it is necessary to model years of operation.
Computational tools based in Object and Lattice Kinetic Monte Carlo techniques (OKMC and LKMC, respectively) achieve the scales and ranges involved in this kind of processes. MASTIC (Multi Atomistic Monte Carlo Simulator of Technologically Important Crystals) project, improves the scientific understanding in the field, generates efficient models for technology development and provides an Open Source simulation workbench to optimize the use of Si and SiGe (microelectronics) and SiC, Fe and FeCr (fusion). The knowledge gained with this project improves the performance of last generation Si-based transistors, and the viability of FeCr based steels as a structural materials in the ITER, future DEMO project and fourth generation fission nuclear reactor designs.
This knowledge is summarized in the following results achieved during the project:
i) Research on OKMC simulation of diffusion and defect evolution in important crystalline materials (both binary and alloys) for microelectronics: SiGe and SiC.
ii) Research on LKMC simulation of epitaxial processes (Solid Phase Epitaxial Regrowth (SPER) and Selective Epitaxial Growth (SEG)) in technologically important crystals and binary alloys for microelectronics: Si, Ge, and SiGe.
iii) Research on OKMC models for the study of technologically important crystals for nuclear applications.
These objectives are based in the pressing urgency of finding new sources of energy and the importance of microelectronics for the information technology, the economy and the wider society.
An infrastructure for binary alloys fully integrated in the OKMC simulator MMonCa has been developed and it is available online for download at http://www.materials.imdea.org/MMonCa. The model is capable of predicting the evolution of point defect diffusion, dopant diffusion and dopant segregation in SiGe alloys. It is also capable of reproducing more complex binary systems such as FeCr alloys that presents stable, metastable and unstable regions in its solid solution miscibility gap (leading to homogenization, nucleation and growth, and spinodal decomposition regions). Cluster formation and dissolution in both, SiGe and FeCr binary alloys, has been modeled and parametrized as well as cluster interaction with the dopants and the solid solution matrix (composition dependent parameters). The model is able to reproduce the behavior of the solid solution in a range of compositions and temperatures below the liquidus. It has been designed to be generic and capable of reproducing diffusion in binary systems. Currently the model is parametrized for SiGe, SiC and FeCr systems.
Development of a comprehensive modeling of the SPER using LKMC for semiconductor materials has also been done during MASTIC as in included in MMonCa. This has been done by an augmented lattice strategy, where several extra atomic configurations have been added to study the amorphous/crystalline transitions of Si-based materials and the formation of defective crystals during this transition.
OKMC and LKMC models have not only been designed, implemented and parametrized but also validated through comparison with real experiments with good agreement between results and calculations, making them useful predictive tools. They (OKMC for binary alloys and LKMC for epitaxial processes) will reduce significantly the number of experiments necessary to design the best process to obtain the desired properties for the microelectronics and nuclear industries and constitute significant advances in the state of the art of current Kinetic Monte Carlo modeling.
The project is already having impact in both fields by ongoing collaborations with global microelectronic companies, and collaborations with several academic organizations in Europe. For microelectronic companies it is important to have accessible and up-to-date tools which they can use, rely and improve, for there everyday R&D departments. For researchers of damage evolution on Fe-based material, the tools and models developed during MASTIC have extended the possibilities to understand the fundamental properties of such materials under irradiation with the final goal of a) customizing materials to be able to stand the very harsh conditions of fusion reactions, and b) predicting the material evolution, and then the safety, of such future installations.
In summary, MASTIC has provided LKMC and OKMC models of generic binary alloys, including defect diffusion and irradiation damage, plus parametrizations for SiGe, SiC and FeCr. and crystalline semiconductors. All these models, code and parameters are available for download as Open Source code at http://www.materials.imdea.org/MMonCa.
More information on the MASTIC project:
Website: http://www.materials.imdea.org/groups/amm/project/mastic-multi-atomistic-monte-carlo-simulation-of-technologically-important-crystals/
Lead researcher: Ignacio Martin-Bragado, ignacio.martin@imdea.org
Project manager: Miguel Ángel Rodiel, miguel.angel.rodiel@imdea.org
Computational tools based in Object and Lattice Kinetic Monte Carlo techniques (OKMC and LKMC, respectively) achieve the scales and ranges involved in this kind of processes. MASTIC (Multi Atomistic Monte Carlo Simulator of Technologically Important Crystals) project, improves the scientific understanding in the field, generates efficient models for technology development and provides an Open Source simulation workbench to optimize the use of Si and SiGe (microelectronics) and SiC, Fe and FeCr (fusion). The knowledge gained with this project improves the performance of last generation Si-based transistors, and the viability of FeCr based steels as a structural materials in the ITER, future DEMO project and fourth generation fission nuclear reactor designs.
This knowledge is summarized in the following results achieved during the project:
i) Research on OKMC simulation of diffusion and defect evolution in important crystalline materials (both binary and alloys) for microelectronics: SiGe and SiC.
ii) Research on LKMC simulation of epitaxial processes (Solid Phase Epitaxial Regrowth (SPER) and Selective Epitaxial Growth (SEG)) in technologically important crystals and binary alloys for microelectronics: Si, Ge, and SiGe.
iii) Research on OKMC models for the study of technologically important crystals for nuclear applications.
These objectives are based in the pressing urgency of finding new sources of energy and the importance of microelectronics for the information technology, the economy and the wider society.
An infrastructure for binary alloys fully integrated in the OKMC simulator MMonCa has been developed and it is available online for download at http://www.materials.imdea.org/MMonCa. The model is capable of predicting the evolution of point defect diffusion, dopant diffusion and dopant segregation in SiGe alloys. It is also capable of reproducing more complex binary systems such as FeCr alloys that presents stable, metastable and unstable regions in its solid solution miscibility gap (leading to homogenization, nucleation and growth, and spinodal decomposition regions). Cluster formation and dissolution in both, SiGe and FeCr binary alloys, has been modeled and parametrized as well as cluster interaction with the dopants and the solid solution matrix (composition dependent parameters). The model is able to reproduce the behavior of the solid solution in a range of compositions and temperatures below the liquidus. It has been designed to be generic and capable of reproducing diffusion in binary systems. Currently the model is parametrized for SiGe, SiC and FeCr systems.
Development of a comprehensive modeling of the SPER using LKMC for semiconductor materials has also been done during MASTIC as in included in MMonCa. This has been done by an augmented lattice strategy, where several extra atomic configurations have been added to study the amorphous/crystalline transitions of Si-based materials and the formation of defective crystals during this transition.
OKMC and LKMC models have not only been designed, implemented and parametrized but also validated through comparison with real experiments with good agreement between results and calculations, making them useful predictive tools. They (OKMC for binary alloys and LKMC for epitaxial processes) will reduce significantly the number of experiments necessary to design the best process to obtain the desired properties for the microelectronics and nuclear industries and constitute significant advances in the state of the art of current Kinetic Monte Carlo modeling.
The project is already having impact in both fields by ongoing collaborations with global microelectronic companies, and collaborations with several academic organizations in Europe. For microelectronic companies it is important to have accessible and up-to-date tools which they can use, rely and improve, for there everyday R&D departments. For researchers of damage evolution on Fe-based material, the tools and models developed during MASTIC have extended the possibilities to understand the fundamental properties of such materials under irradiation with the final goal of a) customizing materials to be able to stand the very harsh conditions of fusion reactions, and b) predicting the material evolution, and then the safety, of such future installations.
In summary, MASTIC has provided LKMC and OKMC models of generic binary alloys, including defect diffusion and irradiation damage, plus parametrizations for SiGe, SiC and FeCr. and crystalline semiconductors. All these models, code and parameters are available for download as Open Source code at http://www.materials.imdea.org/MMonCa.
More information on the MASTIC project:
Website: http://www.materials.imdea.org/groups/amm/project/mastic-multi-atomistic-monte-carlo-simulation-of-technologically-important-crystals/
Lead researcher: Ignacio Martin-Bragado, ignacio.martin@imdea.org
Project manager: Miguel Ángel Rodiel, miguel.angel.rodiel@imdea.org