M. Bouya, D. Carisetti, J. C. Clement, Thales Research and Technology, Palaiseau, France; B. Lambert, UMS, Orsay, France; P. Perdu, CNES - French Space Agency, Toulouse, France; N. N. Labat, N. N. Malbert, IMS Laboratory, Bordeaux, France

Summary: GaN based high electron mobility transistors are actually of major interest due to their high power level performances at high frequenciess. A UV microscopy technique has been developed due to high band gap of these transistors and to locate high electrical field in Drain Source space.