Study of 4H-SiC high voltage bipolar diodes under reverse biases using electrical and Obic characterization

K Isoird (1, 2) , M Lazar (1, 2) , Marie-Laure Locatelli (3, 2) , Christophe Raynaud (1, 2) , Dominique Planson (1, 2) , Jean-Pierre P Chante (1, 2)

1 CEGELY - Centre de génie électrique de Lyon
2 INSA Lyon - Institut National des Sciences Appliquées de Lyon
3 LGET - Laboratoire de génie électrique de Toulouse

4H-SiC P+NN+ structures have been fabricated following MediciTM software simulation in order to block voltages as high as 6 kV. In particular, these diodes are realized by surrounding the emitter by a Aluminum-implanted ring called Junction Termination Extension (JTE). Electrical characterizations under reverse bias at room temperature and in various environments (air, SF6) show a premature breakdown of the diodes. This breakdown is localized at the emitter periphery. OBIC (Optical Beam Induced Current) measurements show a peak of photocurrent at the emitter junction edge, indicating the presence of a high electric field. These results involve an effectiveness of 60 % of the JTE. This is probably related to a low electrical activation of the implanted aluminum during the post-implantation annealing and to the presence of positive charges at the surface of the devices.

Mots clés: OBIC; JTE; Bipolar diode; Breakdown Voltage; Surface charge

Domaines: Energie électrique

K Isoird, M Lazar, Marie-Laure Locatelli, Christophe Raynaud, Dominique Planson, et al.. Study of 4H-SiC high voltage bipolar diodes under reverse biases using electrical and Obic characterization. ICSCRM, Oct 2001, Tsukuba, Japan. ⟨hal-02975956⟩