xxiii πανελληνιο ÏƒÏ Î½ÎµÎ´ÏÎ¹Î¿ Ï†Ï ÏƒÎ¹ÎºÎ·Ï‚ στερεας καταστασης & επιστημης ...

New materials and MOS device concepts for future Si nanoelectronics
Siegfried Mantl
Institute of Bio- und Nanosystems (IBN1) and cni - Center of Nanoelectronic Systems for Information Technology,
Forschungszentrum Juelich, D-52425 Juelich, Germany
*Email address: s.mantl@fz-juelich.de
While in the past performance improvement in microelectronics was mainly achieved by scaling the transistors to smaller
dimensions, an additional boost is now expected from the implementation of new materials and new device concepts. Our
research program in Juelich addresses some of these issues. We place particular emphasis on new channel materials with
higher carrier mobilities. A representative example is the research on strained semiconductors, in particular, the fabrication
of strained silicon on insulator (sSOI) wafers. For this purpose, we developed a new process, involving ion implantation and
annealing to relax thin SiGe layers to form the virtual substrates. Biaxially strained Si is achieved by the growth of Si on the
relaxed SiGe layer due to the lattice mismatch of these materials. Structural properties of the sSOI wafers and mobility
measurements as well as results on first sSOI transistors will be presented. Another exciting research topic are alternative
gate dielectrics. Presently, we investigate ternary rare earth based oxides, e.g. Scandates and LaLuOx. Their electrical
characterisation reveals dielectric constants around 30. Furthermore, we are working on new transistor concepts. As an
example, ultra thin body Schottky barrier transistors with NiSi source and drain contacts with low effective Schottky barriers
will be presented. The smaller the device dimensions the more stringent are the requirements on the electrostatic control to
minimize short channel devices. In order to address this issue an outlook of new device concepts will be given.
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