Dresden 2003 – wissenschaftliches Programm
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HL 40: Grenz- und Oberfl
HL 40.1: Vortrag
Donnerstag, 27. März 2003, 11:00–11:15, BEY/154
Interface Characterization of the High-k Gate Dielectric Pr2O3 — •Hans-Joachim Müssig1, Jarek Dabrowski1, and Dieter Schmeisser2 — 1IHP, Im Technologiepark 25, D-15236 Frankfurt (Oder), Germany — 2BTU, Angewandte Physik-Sensorik, Postfach 101344, D-03013 Cottbus, Germany
Pr2O3 is currently under consideration as a potential alternative gate dielectric candidate for sub-0.1 µm Complementary Metal Oxide Semiconductor (CMOS) technology. For all thin gate dielectrics, the interface with silicon plays a key role, and in most cases is a dominant factor in determining overall electrical properties. We studied the Pr2O3/Si(001) interface by a non-destructive depth profiling using synchrotron radiation photo-electron spectroscopy and ab initio calculations. Our results provide evidence that a chemical reactive interface exists consisting of a mixed Si-Pr oxide such as (Pr2O3)x(SiO2)1−x, typically in non-stoichiometric composition. There is no formation of neither an interfacial SiO2 nor interfacial silicide: all Si-Pr bonds are oxidized and all SiO4 units dissolve in the Pr oxide. Interfacial silicates like (Pr2O3)x(SiO2)1−x are promising high-k dielectric materials because they represent incremental modification of SiO2 films by Pr ions so that the interface characteristics can be similar to Si-SiO2 interface properties. Under ultrahigh vacuum conditions, silicide formation is observed when the silicate film is heated above 800∘C. The praseodymium silicate system observed at the interface between Si(001) and Pr2O3 offers greater flexibility towards integration of Pr2O3 into future CMOS technologies.