Temperature‐Dependent Elemental Diffusion at the Ta/O‐Diamond Interface Under Low‐Oxygen Conditions

Diamond is an ideal semiconductor for high‐temperature, high‐voltage applications due to its wide band gap, high carrier mobility, and high thermal conductivity. Diamond Schottky barrier diodes (SBDs) have been intensively developed; however, their thermal stability has not been explored comprehensively. Considering that the diamond/metal interface is one key factor affecting the thermal stability, in this work, we employed tantalum (Ta)/oxygen‐terminated (O‐) diamond system and investigated the impact of annealing temperature (300°C, 600°C, 900°C, and 1200°C) on chemical and structural evolution of the Ta/O‐diamond interface under low‐oxygen ambient. Angle‐resolved X‐ray photoelectron spectroscopy (ARXPS) and atomic force microscopy (AFM) were performed to examine the interface reactions and surface morphologies. Furthermore, the possible mechanism of the interface evolution under low‐oxygen ambient was discussed. This work provides insights into understanding the interface evolution and thus the thermal stability Ta/O‐diamond.