Improved the C–V Curve Shift, Trap State Responsiveness, and Dynamic R ON of SBDs by the Composite 2-D–3-D Channel Heterostructure Under the OFF-State Stress

In this article, the C-V curve shift, trap densities responsiveness,and dynamic RONof AlGaN/GaN/GaN:C (SH:C) and AlGaN/GaN/graded-AlGaN:Si/GaN:C (DH:Si/C) heterostructure Schottky barrier diodes (SBDs) have been systematically analyzed. Due to additional 3-D electrons in graded-AlGaN:Si layer, the composite 2-D-3-D channel of DH:Si/C has a higher carrier concentration. Reducing the OFF-state electric field strength through AlGaN:Si insert layer, a smaller positive shift of C-V curve is achieved under OFF-state stress. Due to the charge shielding effect of AlGaN:Si insert layer, trapping/detrapping effects in GaN:C buffer under the OFF-state stress are well suppressed. Compared with SH:C heterostructure, the trap density responsiveness of DH:Si/C heterostructure under OFF-state stress is significantly reduced. At the same time, trap density responsiveness of the upper channel is immune to OFF-state electric stress time. In addition, the proposed SBDs show lower ON-resistance with on reverse bias stress and better dynamic performance with on reverse stress time.