Work function analysis of GaN-based lateral polarity structures by Auger electron energy measurements

Lateral polarity heterostructure (LPH) was grown with adjacent Ga- and N-face domains in order to invert the polarity of the crystal within a periodicity of a few microns. In this study we focus on the analysis of these LPH by Auger electron spectroscopy (AES). Because of the relationship between the Auger electron energy and the Fermi level, AES is a suitable method to identify the domains of a lateral polarity heterostructure. In addition, we discuss the possibility of determining the work function difference of Ga- and N-face GaN. This difference in the work function between Ga-face and N-face GaN is found to be 0.25eV. This difference is caused by a surface band bending.