ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
A high field-effect mobility peak (50 cm2/Vs) has been extracted in (0001) Si face 4HSiCMOSFETs with oxidized Ta2Si (O-Ta2Si) high-k dielectric (k~20) as gate insulator, with theirgates in the strong inversion regime. The interface state density (Dit) has not been particularlyreduced in O-Ta2Si capacitors. This anomalous mobility enhancement is explained in terms ofCoulomb scattering reduction and quantified using a physical model based on the Lombardimobility model. The anomalous mobility increase is closely related to the leakage current, and alsoto the gate breakdown mechanism. We propose a model for which the observed interfacial SiO2tunnel current combined with Poole-Frenkel mechanisms at the O-Ta2Si gate generates asufficiently low abrupt transition in gate breakdown to obtain an effective passivation of theinterface traps. Under these conditions, the increase of free carriers in the inversion layer inducedby the gate leakage diminishes the effect of the interface trap Coulomb scattering
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.527-529.1059.pdf
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