Vertical Field-Plated NiO/Ga2O3 Heterojunction Power Diodes

Abstract

The β-Ga2O3 has exceptional electronic properties with vast potential in power and RF electronics.Despite the excellent demonstrations of high-performance unipolar devices, the lack of p-type doping in β-Ga2O3 has hindered the development of Ga2O3-based bipolar devices. The approach of p-n diodes formed by polycrystalline p-type oxides with n-type β-Ga2O3 can face severe challenges in further advancing the β-Ga2O3 bipolar devices due to their unfavorable band alignment and the poor p-type oxide crystal quality. In this work, we applied the semiconductor grafting approach to fabricate monocrystalline Si/β-Ga2O3 p-n diodes for the first time. With enhanced concentration of oxygen atoms at the interface of Si/β-Ga2O3, double side surface passivation was achieved for both Si and β-Ga2O3 with an interface Dit value of 1-3 × 10 12 /cm 2 ⋅eV. A Si/β-Ga2O3 p-n diode array with high fabrication yield was demonstrated along with a diode rectification of 1.3 × 10 7 at ±2 V, a diode ideality factor of 1.13 and avalanche reverse breakdown characteristics. The diodes C-V shows frequency dispersion-free characteristics from 10 kHz to 2 MHz. Our work has set the foundation toward future development of β-Ga2O3-based transistors.

Recent advances in NiO/Ga2O3 heterojunctions for power electronics

“…The device yielded a BV of 1059 V with an ultra-low leakage current of The trap states located within the sputtered NiO and at the heterojunction interface significantly affect the device performance of a NiO/β-Ga 2 O 3 HJD. A PDA process has been proven as an effective method to improve the crystallinity of the sputtered NiO and reduce the defects density at the het-ero-interface [48,49,66] . Moreover, the PDA process could also improve the metal-to-NiO Ohmic contact.…”

Gate-Controlled NiO/Graphene/4H-SiC Double Schottky Barrier Heterojunction Based on a Metal-Oxide-Semiconductor Structure for Dual-Mode and Wide Range Ultraviolet Detection

“…In previous research, the photodetector with a single graphene/WBS heterojunction usually exhibits a narrow UV response bandwidth, making it hard to detect wide range UV light. ,, Researchers have found that graphene can be epitaxially grown on the surface of SiC, which opens up a novel material system for photodetectors. , 4H-SiC has a bandgap of 3.26 eV and an excellent near UV response. , In order to broaden the UV detection range while maintaining acceptable conduction, combining the graphene SBJ with another WBS material to form a double Schottky heterojunction may be a promising option. Another p-type WBS material, nickel oxide (NiO), has recently been investigated and employed in power devices. − NiO has a bandgap of 3.7 eV, making it an excellent UV sensitive material. The photoresponse of NiO coupled with other materials has been studied. − However, these conventional p–n junction photodiodes had a relatively narrow response range or almost no gain.…”

Field-Plated NiO/Ga2O3 p-n Heterojunction Power Diodes With High-Temperature Thermal Stability and Near Unity Ideality Factors

“…Benefiting from the superior material advantages of ultra-wide bandgap, enhanced critical electric field and the availability of large-sized substrates, high performance β-Ga 2 O 3 -based unipolar devices such as Schottky barrier diodes (SBDs) and MOSFET switches have been demonstrated [1][2][3]. To enhance the reserve blocking capability, the NiO/Ga2O3 p-n heterojunction diodes (HJDs) has been demonstrated as a very promising strategy to realize advanced bipolar rectifiers, which alternatively overcomes the technological bottleneck of p-type Ga 2 O 3 [4][5][6][7][8][9]. These developed p-n HJDs have exhibited large current outputs, low specific on-resistances (Ron,sp) and enhanced breakdown voltages (BVs), which are of particular interest and importance to high-power, high-temperature and low-losses applications [6][7][8][9].…”

“…To enhance the reserve blocking capability, the NiO/Ga2O3 p-n heterojunction diodes (HJDs) has been demonstrated as a very promising strategy to realize advanced bipolar rectifiers, which alternatively overcomes the technological bottleneck of p-type Ga 2 O 3 [4][5][6][7][8][9]. These developed p-n HJDs have exhibited large current outputs, low specific on-resistances (Ron,sp) and enhanced breakdown voltages (BVs), which are of particular interest and importance to high-power, high-temperature and low-losses applications [6][7][8][9]. However, due to severe electric field crowding at the NiO/β-Ga2O3 mesa edge, the non-uniform electric field distribution has been observed.…”

“…Furthermore, the device performance is also limited by the interface quality, and the post-thermal process has been reported as a straightforward but effective approach to improve electrical performance [8]. In this work, we developed the vertical NiO/Ga2O3 HJDs with SiNx/Al2O3 double-layered insulating field plate (FP) structures and the post-thermal treatment [9]. It is widely accepted that negative fixed charges exist in the ALD-grown Al 2 O 3 films while the fixed charges in the PECVD-grown SiNx films are positive.…”