Leakage Current Modelling and Optimization of β-Ga ₂ O ₃ Schottky Barrier Diode with Ni Contact under High Reverse Voltage

Abstract

The reverse leakage current under high reverse voltage of a Ni/β-Ga 2 O 3 Schottky barrier diode (SBD) is numerically modelled and compared to measurements. universal Schottky tunnelling, thermionic emission and image-force lowering were taken into account. Furthermore, when type conversion under high reverse voltage has occurred at the top interface between Ni and β-Ga 2 O 3 and the SBD behaved as P–i–N diode, band to band tunnelling is proposed in association with the usually used Selberherr’s Impact ionization to model avalanche breakdown. The obtained breakdown voltage and specific on-resistance value are 434 V and 2.13 mΩ·cm2, respectively, fairly close to measurement values of 440 V and 2.79 mΩ·cm2. Optimization is performed based on the insertion of an intrinsic layer between Ni and the β-Ga 2 O 3 drift layer. It was found that 0.4 μm gave better Baliga’s figure of merit of 9.48107 W·cm−2 with breakdown voltage and specific on-resistance of 465 V and 2.28 mΩ·cm2, respectively. Finally, a surface edge termination design based on TiO2 insulator plate is adopted and the best obtained breakdown voltage, Baliga’s figure of merit and specific on-resistance were 1466 V, 1.98 × 109 W·cm−2 and 1.98 mΩ·cm2 respectively.

Room‐Temperature Processed Lateral Trench‐Metal–Insulator–Semiconductor Schottky Barrier Diodes with Amorphous Gallium Oxide (a‐Ga2O3) Thin Films on Single‐Crystal Silicon <100>

“…This diagram demonstrates a simplified view of the Al/a‐Ga 2 O 3 /Si heterojunction energy band, and does not represent the precise scaled diagram obtained by actual measurements. [ 39,40 ] From the same picture, one may observe that the lateral device structure contains Al/a‐Ga 2 O 3 Schottky junction in series with a‐Ga 2 O 3 /Si heterojunction. The device working principle and fundamentals are discussed with great detail in the following sections.…”

Control of Ni/β-Ga2O3 Vertical Schottky Diode Output Parameters at Forward Bias by Insertion of a Graphene Layer

“…The dominant transport mechanism of electrons from Ni to graphene is a tunneling mechanism. Tunnelling was considered by using the Universal Schottky Tunnelling (UST) model and the tunnelling current is given by [ 7 ]: where , , , ϵ , , and are the effective Richardson’s coefficient (41.11 for β-Ga 2 O 3 [ 2 ]), the lattice temperature, the Boltzmann constant, the electron energy, and the Maxwell–Boltzmann distribution in the semiconductor and metal, respectively, and is the tunnelling probability given by [ 7 ]: where , ( , and are the potential energy distribution of the Schottky barrier diode, the classical turning points, and the tunnelling mass in graphene ( = 0.012m 0 where m 0 is the free electron mass [ 24 ]), respectively. In addition, the thermionic emission plays an important role in this type of device.…”

“…Furthermore, it can be grown directly from the melt at a low cost and allows for large-scale production compared with GaN, InGaN, and SiC [ 1 , 2 , 4 ]. However, this material has a problem with developing a stable p-type [ 2 , 5 , 6 , 7 ]. As a result, its use in bipolar devices is limited to a heterojunction with other p-type materials such as NiO [ 8 , 9 ] and Cu 2 O [ 10 ].…”

Physical Operations of a Self-Powered IZTO/β-Ga2O3 Schottky Barrier Diode Photodetector

“…Gallium oxide (Ga 2 O 3 ) is an oxide semiconductor material with a long, rich history [ 1 , 2 , 3 ]. It has an ultra-wide bandgap (UWBG) of ~4.8 eV, a high breakdown electric field of ~8 MV/cm, and a high saturation velocity of 1 × 10 7 cm/s, and these properties have brought Ga 2 O 3 to the fore once again [ 1 , 2 , 4 ]. Ga 2 O 3 has six polymorphs, i.e., and with β-Ga 2 O 3 being the most stable [ 1 ].…”

“…Ga 2 O 3 has six polymorphs, i.e., and with β-Ga 2 O 3 being the most stable [ 1 ]. Unipolar devices based on β-Ga 2 O 3 , such as the metal–oxide–semiconductor field-effect transistor (MOSFET) [ 5 ], thin film transistor (TFT) [ 6 ], field emission (FE) [ 7 ], and Schottky barrier diode (SBD) [ 1 , 2 , 3 , 4 , 8 , 9 ], have been studied extensively. It is also used for deep ultraviolet (DUV) photodetectors (PDs) for solar-blind applications [ 10 , 11 ].…”