The vulnerable nanoscale dielectric

It was the wide-gap insulating oxide that made silicon the semiconductor of choice, to such a degree that silicon technology has transformed our lives. Its roles of surface passivation and as a lithographic material are essential, but its role as the gate dielectric is especially sophisticated. Even though challenged by newer materials, like HfO 2, the silicon dioxide dielectric will be around for some time. We discuss some of the key defect processes in these oxides in materials context. What materials must work alongside silicon? To what extent do silica glasses share properties with the gate dielectric oxide? And are there new phenomena to exploit? To illustrate and partially address some of these issues we present and compare the results of calculations of the properties of oxygen vacancies in SiO 2, HfO 2 and HfSiO 4. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA