1.4-kV Quasi-Vertical GaN Schottky Barrier Diode With Reverse p-n Junction Termination

Abstract

In this paper, we demonstrate high-performance quasi-vertical GaN-on-Sapphire Schottky barrier diodes (SBD) with a reverse GaN p-n junction termination (RPN). The SBD has a current output of 1 kA/cm 2 at V F = 2.5 V, a low V on of 0.66 V ± 0.017 V, a low R on,sp of 1.4 m •cm 2 , current ON/OFF ratio of over 10 9 (−3 V∼3 V). By introducing the RPN, the breakdown voltage can boost from 459 V to 1419 V, and power figure-of-merit (FOM) can reach 1438 MV/cm 2. It is shown that the presence of the RPN with a suitable anode recess depth can generate an electric field (EF) opposite to the built-in EF at the center of the second top p-n junction, which can decrease the EF peak intensity and make the electric field more uniformly distributed inside the device. Finally, the leakage current of the SBD is inhibited and the breakdown voltage is increased. INDEX TERMS Vertical GaN-on-Sapphire Schottky barrier diode, reverse p-n GaN junction, breakdown voltage, power FOM.

Low Leakage and High Forward Current Density Quasi-Vertical GaN Schottky Barrier Diode With Post-Mesa Nitridation

“…One of them is the large reverse leakage current [14], which can cause OFF-state power loss and reliability problems [15]. Some literatures suggest that it is possible to inhibit the leakage currents by junction termination techniques [7], [16], [17], reducing dislocation density of GaN epitaxial layer [18]- [20], passivating the etch mesa sidewall [21], reducing the doping concentration of GaN drift layer [22], [23], and decreasing the interface defect density at the Schottky contact interface [24].…”

Review of Recent Progress on Vertical GaN-Based PN Diodes

“…Consequently, varied edge termination structures are proposed to improve performance. Through the assistance of varied edge termination technologies [27,28,30,31], the high current density at KA/cm 2 grade with BVs over 1 kV is confirmed. Meanwhile, vertical SBDs also exhibit great capability for high frequency, such as 177-183 GHz and a maximum of 902 GHz cutoff frequency at 0 V, a feature which is expected for power sources in terahertz-wireless communication systems [12,32].…”

“…Fig. 2 Overview of the device types, reports, and voltage classes of main vertical GaN power devices reported in recent years [26] Compared with PNDs, which have no minority carrier storage issue and lower SBD barrier height, GaN SBDs feature a low forward turn-on voltage (V on ) and fast reverse recovery, and these characteristics indicate that the merits of SBD are revealed in low conduction/ switching loss, high-frequency operation, but a lower BV value than that of PND; moreover, note that high turn-on voltage can lead a high conduction loss and degrade the efficiency of circuits and systems [27,28].…”

High Power Figure‐of‐Merit, 10.6‐kV AlGaN/GaN Lateral Schottky Barrier Diode with Single Channel and Sub‐100‐µm Anode‐to‐Cathode Spacing

“…It is well known that the anode field plate (AFP) can effectively modify the EF distribution and then increase the BV . In our previous work, [ 33–35 ] prior to the fabrication of the SBDs on Si, we also used Silvaco‐TCAD to simulate and optimize the AFP parameters. The simulated BV is highly depended on the AFP length and SiN x passivation layer thickness.…”

“…The detailed fabrication process is shown in the Experimental Section, and some process parameters and the main results have been reported in our previous work. [ 33–36 ]…”