Publications by April S. Brown.

Papers Published

  1. Losurdo, M. and Giangregorio, M.M. and Bruno, G. and Brown, A.S. and Doolittle, W.A. and Ptak, A.J. and Myers, T.H., Surface potential measurements of doping and defects in p-GaN, GaN and Related Alloys - 2003 Symposium (Mater. Res. Soc. Symposium Proceedings Vol.798) (2004), pp. 805 - 10 .
    (last updated on 2007/04/14)

    Abstract:
    The interaction of Be-, Mg-, and Si- doped GaN epitaxial films with atomic hydrogen, produced by a remote r.f. hydrogen plasma, is investigated. The kinetics of the interaction is monitored in real time by spectroscopic ellipsometry through the measurement of the variation of the GaN pseudodielectric function. The passivation effect of hydrogen is inferred by surface potential measurements using scanning Kelvin probe microscopy (SKPM). It is found that the interaction of GaN with hydrogen is a strong function of both the type and level of the doping. Hydrogen treatment is shown to lead to a strong variation of the surface potential and, hence, of the Fermi level position, which is the result of p-dopant passivation by hydrogen. A different interaction of Mg and Be with atomic hydrogen is also observed and monitored in real time by ellipsometry. SKPM is also used for studying the interaction of defects in GaN with atomic hydrogen

    Keywords:
    beryllium;dielectric function;ellipsometry;Fermi level;gallium compounds;hydrogen;III-V semiconductors;magnesium;passivation;semiconductor epitaxial layers;silicon;surface potential;wide band gap semiconductors;