Determination of 4H-SiC ionization rates using OBIC based on two-photon absorption

Hassan Hamad (1, 2) , Christophe Raynaud (1, 2) , Pascal Bevilacqua (1, 2) , S Sharnholz (3) , Bertrand Vergne (3) , Dominique Planson (1, 2)

1 EE - Ampère, Département Energie Electrique
2 INSA Lyon - Institut National des Sciences Appliquées de Lyon
3 ISL - Institut franco-allemand de recherches de Saint-Louis

Ionization rates are requested to predict the breakdown voltage of electronic devices. They are used in numerical simulators like SENTAURUS TCAD [1] in order to model the leakage current and the breakdown of the devices. They are rarely studied and the results already published are, more or less, scattered [2-4]. Many methods like OBIC or EBIC (Optical/Electron Beam Induced Current) are used to determine the ionization rates. In this paper, OBIC method is used in 4H-SiC. An optical beam illuminates perpendicularly a reverse biased PN junction. Photon absorption process leads to generate electron-hole pairs (EHPs). EHPs created in the space charge region (SCR) will be accelerated by the electric field and thus an induced current is measured, hence the naming of the method: Optical Beam Induced Current OBIC. For voltages close to the breakdown voltage, the electric field becomes high, the EHPs gain a kinetic energy and collide with the atoms in the crystalline structure leading to the generation of a new EHPs, which in turns may lead to the creation of new EHPs; this is manifested by an increase of the OBIC signal. The multiplication coefficient is defined as the ratio between the induced current at a given voltage V and at V 0 (for which there is no multiplication).

Domaines: Energie électrique

Hassan Hamad, Christophe Raynaud, Pascal Bevilacqua, S Sharnholz, Bertrand Vergne, et al.. Determination of 4H-SiC ionization rates using OBIC based on two-photon absorption. International Conference on Silicon Carbide and Related Materials 2015 (ICSCRM 2015), Oct 2015, Giardini Naxos, Italy. ⟨hal-02138523⟩