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

Abstract

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. • We fabricated n + -Si/p-diamond heterojunction diodes (HDs) and Ru/p-diamond Schottky barrier diodes (SBDs) on a diamond surface activated using a fast atom beam (FAB) of Ar. • The reverse-bias characteristics of HDs and SBDs were explained by the trap-assisted tunneling model. • The S factors of HDs and SBDs after annealing at 703 K and 873 K were close to 0.7 and 0.6, respectively, which suggested that the partially “pinning-free” interfaces were formed thank to FAB irradiation.