Design optimization of high breakdown voltage vertical GaN junction barrier Schottky diode with high-K/low-K compound dielectric structure

A vertical junction barrier Schottky diode with a high-K/low-K compound dielectric structure is proposed and optimized to achieve a high breakdown voltage(BV).There is a discontinuity of the electric field at the interface of high-K and low-K layers due to the different dielectric constants of high-K and low-K dielectric layers.A new electric field peak is introduced in the n-type drift region of junction barrier Schottky diode(JBS),so the distribution of electric field in JBS becomes more uniform.At the same time,the effect of electric-power line concentration at the p-n junction interface is suppressed due to the effects of the high-K dielectric layer and an enhancement of breakdown voltage can be achieved.Numerical simulations demonstrate that GaN JBS with a specific on-resistance(R_(on,sp)) of 2.07 mΩ·cm^(2) and a BV of 4171 V which is 167% higher than the breakdown voltage of the common structure,resulting in a high figure-of-merit(FOM) of 8.6 GW/cm^(2),and a low turn-on voltage of 0.6 V.

Influence of dry-etching damage on the electrical properties of an AlGaN/GaN Schottky barrier diode with recessed anode

The influences of dry-etching damage on the electrical properties of an AlGaN/GaN Schottky barrier diode with ICPrecessed anode was investigated for the first time. It was found that the turn-on voltage is decreased with the increase of dry-etching power. Furthermore, the leakage currents in the reverse bias region above pinch-off voltage rise as radio frequency（RF） power increases, while below pinch-off voltage, leakage currents tend to be independent of RF power.Based on detailed current–voltage–temperature（I–V –T） measurements, the barrier height of thermionic-field emission（TFE） from GaN is lowered as RF power increases, which results in early conduction. The increase of leakage current can be explained by Frenkel–Poole（FP） emission that higher dry-etching damage in the sidewall leads to the higher tunneling current, while below pinch-off voltage, the leakage is only related to the AlGaN surface, which is independent of RF power.

The Cu Based AlGaN/GaN Schottky Barrier Diode

The electrical characteristics of Cu and Ni/Al AlGaN/GaN Schottky barrier diodes on Si su bstrates are compared. The onset voltage of Cu Schottky diodes is about 0.4 V less than the Ni/Al contact. For the Cu/Ni Schottky contact, the leakage current is 4.7 × 10^-7 A/mm at -10 V. After annealing, the leakage current is decreased to 3.7 × 10^-7 A/mm for 400℃ or 4.6 × 10^-8 A/mm for 500℃, respectively. The electrical property is affected by the thickness ratio of Cu to Ni. The Cu/Ni for 80/20 nm shows a low onset voltage, while the Cu/Ni for 20/80 nm shows a low leakage current. Both breakdown voltages are above 720 V.

A lateral AlGaN/GaN Schottky barrier diode with 0.36-V turn-on voltage and 10-kV breakdown voltage by using double-barrier anode structure

GaN power electronic devices,such as the lateral AlGaN/GaN Schottky barrier diode(SBD),have received significant attention in recent years.Many studies have focused on optimizing the breakdown voltage(BV)of the device,with a particular emphasis on achieving ultra-high-voltage(UHV,>10 kV)applications.However,another important question arises:can the device maintain a BV of 10 kV while having a low turn-on voltage(V_(on))?In this study,the fabrication of UHV AlGaN/GaN SBDs was demonstrated on sapphire with a BV exceeding 10 kV.Moreover,by utilizing a doublebarrier anode(DBA)structure consisting of platinum(Pt)and tantalum(Ta),a remarkably low Von of 0.36 V was achieved.This achievement highlights the great potential of these devices for UHV applications.