Clarifying the processing of germanium for applications in micro and nanoelectronics<\/strong><\/p>\n Germanium (Ge) is one of the semiconductor materials listed as possible alternatives to silicon for applications in the micro and nanoelectronics industry. However, the processing of materials based in germanium, aiming to optimize its electric properties for these applications is still presented as a challenge to the science.<\/p>\n In this context, a research team from the Federal University of Rio Grande do Sul (UFRGS) investigated the heat treatment (annealing<\/em>) of germanium structures in deuterium atmosphere (hydrogen isotope which allows the use of analytical techniques specified\u00a0 for its quantification). The results of the study were recently published in the renowned periodical Applied Physics Letters<\/em> (APL).<\/p>\n The study which the cited article derived from is part of the PhD research, in progress, by Nicolau Molina Bom, supervised by Professor Claudio Radtke in the framework of the postgraduate program in Microelectronics from UFRGS. \u201cThis work came up as a sequency of studies developed during my Masters, involving systems of aluminium oxide on germanium (Al2<\/sub>O3<\/sub>\/Ge)\u201d, Nicolau reports.<\/p>\n In the Masters\u2019 research, also supervised by Radtke, Bom observed that the deposition of dielectric materials on germanium substrates, as well as its processing by means of heat treatment, induces the semiconductor oxidation and the formation of zirconium dioxide (GeO2<\/sub>). Due to reactions that occur between the oxide that is formed and the germanium substrate, the structure causes physical and chemical changes which bring about the degradation of its electric properties. \u201cThus, it became clear that the understanding of these mechanisms was fundamental to the use of germanium in industrial applications\u201d, says Bom.<\/p>\n Incorporation of hydrogen<\/strong><\/p>\n In the article published in APL, the authors report that the heat treatment was carried out in samples of germanium oxide on germanium (GeO2<\/sub>\/Ge), of germanium oxide on silicon (GeO2<\/sub>\/Si) and of silicon dioxide on silicon (SiO2<\/sub>\/Si). One of the effects of the treatment evinced by means of analysis was the hydrogen incorporation, to greater proportions in GeO2<\/sub>\/Ge than in SiO2<\/sub>\/Si.<\/p>\n Authors assigned this effect to the occupation by hydrogen atoms of oxygen vacancies (points of crystalline network in which there are \u201cvacancies\u201d in the place of atoms that would be expected to be there), brought about during the heat treatment, in the interior of the germanium dioxide and\u00a0 in the GeO2<\/sub>\/Ge interface.<\/p>\n
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