X-ray photoelectron spectroscopy investigation of the valence band offset at beryllium oxide-diamond interfaces

Owing to a large bandgap, extreme thermal-mechanical properties, and close lattice matching, beryllium oxide (BeO) is an ideal substrate and dielectric material for diamond based electronic devices. In this regard, we have utilized X-ray photoemission spectroscopy (XPS) to determine the valence band offset (VBO) between atomic layer deposited (ALD) BeO and nano-crystalline diamond (nc-D). The BeO VBO with nc-D was determined to be 1.8 ± 0.1 eV. Utilizing the reported band gaps for ALD BeO (8.0 eV) and diamond (5.5 eV), the calculated conduction band offset at the BeO/nc-D interface was determined to be 0.7 ± 0.2 eV. The measured BeO/nc-D band offsets are accordingly ideal for high-power, −temperature, −frequency, and nuclear detection device applications based on diamond technology.