Electrical and physical characteristics for crystalline atomic layer deposited beryllium oxide thin film on Si and GaAs substrates

Abstract

In a previous study, atomic layer deposited (ALD) BeO exhibited less interface defect density and hysteresis, as well as less frequency dispersion and leakage current density, at the same equivalent oxide thickness than Al2O3. Furthermore, its self-cleaning effect was better. In this study, the physical and electrical characteristics of ALD BeO grown on Si and GaAs substrates are further evaluated as a gate dielectric layer in III-V metal-oxide-semiconductor devices using transmission electron microscopy, selective area electron diffraction, second harmonic generation, and electrical analysis. An as-grown ALD BeO thin film was revealed as a layered single crystal structure, unlike the well-known ALD dielectrics that exhibit either poly-crystalline or amorphous structures. Low defect density in highly ordered ALD BeO film, less variability in electrical characteristics, and great stability under electrical stress were demonstrated.