(Invited, Digital Presentation) Improved Reliability of 4H-SiC Metal-Oxide-Semiconductor Devices Utilising Atomic Layer Deposited Layers with Enhanced Interface Quality

An investigation into the effect of deposition, growth and conditioning of the SiO2/SiC interface in MOS capacitors is performed, where the enhancement of reliability is characterised. Various methods of oxide formation are compared: ALD, LPCVD and thermally grown. ALD-deposited oxides were post-deposition annealed in nitrous oxide ambient, resulting in average flatband voltages of 0.63 V and low D IT levels, down to 7 x 1011 cm-2 eV-1 at EC-ET =0.2 eV. These samples also outperformed their counterparts in terms of high leakage and constant voltage TDDB performance, which was done at 175°C, averaging breakdown electric fields of 9.84 MV/cm and a 63% failure stress time of 11220 s when stressed at 8 MV/cm.