FERMI LEVEL ANALYSIS OF GROUP III NITRIDE SEMICONDUCTOR DEVICE STRUCTURES BY AUGER PEAK POSITION MEASUREMENTS

Gernot Ecke - Merten Niebelschütz - Rastislav Kosiba - Uwe Rossow - Volker Cimalla - Jozef Liday - Peter Vogrinčič - Jörg Pezoldt - Vadim Lebedev - Oliver Ambacher

   The peak position of characteristic Auger transitions depends on the position of the Fermi level of the sample electrons. Thus, Auger electron spectroscopy can be applied for detection of semiconductor conduction type with a high lateral resolution typical for Auger electron spectroscopy mapping. Moreover, the peak position can be evaluated, even if the semiconductor surface is cleaned by sputtering. In this work, the Auger peak position measurements have been applied to GaN p-n-junctions as in cross section geometry as well as in Auger depth profiles. The method has also successfully been applied to n- and p- type doped AlGaN, and to Mg doped InN samples. It was observed that the differences in Auger peak positions from n- to p-type GaN and AlGaN differ from the theoretical prediction due to the impact of surface charges and additional band bending effects induced by the sputtering process.

Keywords: group III nitrides, sputter depth profiling, Auger Electron Spectroscopy, Auger peak position, Fermi level

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