Electrical properties of Si/diamond heterojunction diodes fabricated by using surface activated bonding

We evaluated the current–voltage (I-V) and temperature-dependent I-V characteristics of n+-Si/p-diamond heterojunction diodes (HDs) fabricated by using surface activated bonding and Ru/p-diamond Schottky barrier diodes (SBDs). Both types of diodes were fabricated on diamond surface that was activated using a fast atom beam of Ar. Their room-temperature reverse-bias characteristics were explained using the trap-assisted tunneling model, wherein the surface activation process affects the carrier transport across the Si/diamond and Ru/diamond interfaces. In addition, we compared the electrical properties of n+-Si/p-diamond HDs and Ru/p-diamond SBDs with those of previously fabricated p+-Si/p-diamond HDs and Al/p-diamond SBDs. A correlation between the barrier heights and the work function of the contact materials (n+-Si, p+-Si, and Ru) was observed. [Display omitted] •We fabricated n+-Si/p-diamond heterojunction diodes (HDs), and demonstrated their diode characteristics.•The reverse-bias characteristics of HDs were explained by the trap-assisted tunneling model.•The S factors of Si/diamond and Ru/diamond interfaces was as high as ≈0.7 after annealing at 703 K.•The partially “pinning-free” interfaces were formed thank to Ar beam irradiation.