Dielectric reliability and interface trap characterization in MOCVD grown in situ Al2O3 on β-Ga2O3

In this article, we investigate the in situ growth of Al2O3 on beta-Ga(2)O(3)using metal-organic chemical vapor deposition at a high temperature of 800 degrees C. The Al2O3 is grown within the same reactor as the beta-Ga2O3, employing trimethylaluminum and O-2 as precursors without breaking the vacuum. We characterize the shallow and deep-level traps through stressed capacitance-voltage (C-V) and photo-assisted C-V methods. The high-temperature deposited dielectric demonstrates an impressive catastrophic breakdown field of approximately 10 MV/cm. Furthermore, we evaluate the reliability and lifetime of the dielectrics using time-dependent dielectric breakdown measurements. By modifying the dielectric deposition process to include a high-temperature (800 degrees C) thin interfacial layer and a low-temperature (600 degrees C) bulk layer, we report a 10-year lifetime under a stress field of 3.5 MV/cm along a catastrophic breakdown field of 7.8 MV/cm.