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:
We present a novel approach based on conductive atomic force microscopy (c-AFM) fornano-scale mapping of the Schottky barrier height (SBH) between a semiconductor and an ultrathin(1-5 nm) metal film. The method was applied to characterize the uniformity of the Au/4H-SiCSchottky contact, which is attractive for applications due to the high reported (∼1.8 eV) SBH value.Since this system is very sensitive to the SiC surface preparation, we investigated the effect on thenano-scale SBH distribution of a ∼2 nm thick not uniform SiO2 layer. The macroscopic I-Vcharacteristics on Au/SiC and Au/not uniform SiO2/SiC diodes showed that the interfacial oxidelowers the average SBH. The c-AFM investigation is carried out collecting arrays of I-V curves fordifferent tip positions on 1μm×1μm area. From these curves, 2D SBH maps are obtained with 10-20 nm spatial resolution and energy resolution 〈0.1 eV. The laterally inhomogeneous character ofthe Au/SiC contact is demonstrated. In fact, a SBH distribution peaked at 1.8 eV and with tails from1.6 eV to 2.1 eV is obtained. Moreover, in the presence of the not uniform oxide at the interface, theSBH distribution exhibits a 0.3 eV peak lowering and a broadening (tails from 1.1 eV to 2.1 eV)
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/17/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.556-557.545.pdf
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