On the Understanding of Cathode Related Trapping Effects in GaN-on-Si Schottky Diodes

International audienceCathode related current collapse effect in GaN on Si Schottky barrier diodes is investigated in this paper. Capacitance and current relaxation measurements on diodes and gated-Van Der Pauw are associated with temperature dependent dynamic ${R_{\mathrm{ ON}}}$ transients analysis to identify the parasitic trapping locations in the devices. We show here that the main part of the current collapse at the cathode comes from a combination of electron trapping in the passivation layer and in a carbon related trap in the GaN buffer layers ( ${E_{A}} = \mathrm {E_{T}} - {E_{V}} \simeq 0.9 \,\mathrm {eV}$ ) that can be studied independently by using the appropriate stress configurations. These two parasitic effects can lead to long recovery time (>1 ks) after reverse bias stress