Non-Contact Doping Profiling in Epitaxial SiC

We present a very fast, non-contact and preparation free method of determining doping concentration and doping depths profiles in silicon carbide epitaxial layers. The method is an extension of the recently patented Q2-V technique. It uses a corona discharge in air for charging the epi-surface with precisely controlled doses of electrical charge, *DQC. Corona charging is followed by non-contact measurement of the surface potential, V, using a vibrating probe. A sequence of charging and measuring steps produces the Q2-V plot that for uniform doping satisfies a linear relation. For nonuniform doping a depth profile is obtained from a derivative, dQ2/dV, similar to the derivative capacitance method.