Post-deposition annealing challenges for ALD Al0.5Si0.5Ox/n-GaN MOS devices

In this work, we investigate the impact of high-temperature Post-Deposition Annealing (PDA) on Al0.5Si0.5Ox deposited by Atomic Layer Deposition (ALD). Reversed hysteresis is observed and explained by mobile charges originating from K+ and Na+ impurities. The high-temperature annealing does not cure the presence of these mobile charges. We also report the onset of film and interface degradation after annealing above 750 degrees C under N2, with both inhomogeneous aluminium and silicon composition, signs of AlSiO crystallization and interfacial gallium oxide growth.