Vertical β -Ga2O3 field plate Schottky barrier diode from metal-organic chemical vapor deposition

Abstract

Vertical β-Ga2O3 Schottky diodes from metal-organic chemical vapor deposition (MOCVD)-grown epitaxial films are reported in this paper for high-power application devices. The Schottky diode, fabricated with a field termination structure, showed a low differential specific on-resistance of 0.67 mΩ cm2. Furthermore, the MOCVD-grown β-Ga2O3 vertical Schottky diodes exhibited a punch-through breakdown and a higher Baliga's figure-of-merit compared to those from other epitaxial growth methods of similar drift layer thickness. This suggests that the MOCVD growth, supporting high-quality epitaxy, can be promising for high-performance β-Ga2O3-based high-power devices.

Ga2O3 Schottky Avalanche Solar‐Blind Photodiode with High Responsivity and Photo‐to‐Dark Current Ratio

“…The avalanche breakdown voltage, evaluated as the inflection point in the reverse current curves, decreases from 28.84 to 2.95 V with the increase of the P from 3 to 64 μW cm −2 , as shown in Figure 3b, due to the increased photo carrier density. The lateral depletion width in the Ga 2 O 3 APDs is estimated to be ≈0.72 μm, [34] and thus the avalanche breakdown electric fields of the APD with the P of 3-64 μW cm −2 are evaluated to be ≈0.04-0.40 MV cm −1 , as shown in Figure 3b, which are comparable to those of the reported Ga 2 O 3 APDs with n-n junctions (0.05 and 0.15 MV cm −1 ). [22,25] To evaluate the avalanche intensity, avalanche gain estimated as [I L (V)-I D (V)]/[I L (1)-I D (1)] is studied.…”

A Comprehensive Review on Recent Developments in Ohmic and Schottky Contacts on Ga2O3 for Device Applications

“…Several researchers have reported using a field plate (FP) edge termination technique to redistribute the electric field at the SC metal periphery under reverse bias. − Konishi et al fabricated FP-SBDs on HVPE-grown (001) epilayers on highly doped bulk conducting β-Ga 2 O 3 substrate as shown in Figure . Based on a two-dimensional device simulation using Silvaco ATLAS, a doping density of about 1 × 10 16 cm –3 in the drift region of 300 nm thick SiO 2 dielectric and FP length of 20 μm were targeted.…”

MOCVD Growth of Thick β-(Al)GaO Films with Fast Growth Rates

“…β-Ga 2 O 3 , an emerging semiconductor material, exhibits immense potential for high-power electronics attributed to its remarkable fundamental material properties, including an ultra-wide bandgap of 4.8 eV , and a high critical field strength of 8 MV/cm . The advancement of β-Ga 2 O 3 -based Schottky diodes and transistors has greatly expanded its promises for power device applications. − Moreover, the ability to control n-type doping within the range of 10 16 to 10 20 cm –3 , − the successful epitaxial growth of semi-insulating layers, , and the availability of high-quality native substrates commercially confer significant advantages to β-Ga 2 O 3 for high-power device applications. Various methods have been employed to grow Ga 2 O 3 on different oriented β-Ga 2 O 3 substrates, such as molecular beam epitaxy (MBE), ,,− pulsed laser deposition (PLD), − halide vapor phase epitaxy (HVPE), ,− low-pressure chemical vapor deposition (LPCVD), − and metalorganic chemical vapor deposition (MOCVD). ,− ,− In order to facilitate the application of high-performance power electronics with substantial breakdown capabilities, the incorporation of a thick drift layer becomes necessary.…”

“…However, high-growth-rate HVPE processes often result in considerable surface roughness, characterized by surface steps and pits, necessitating the implementation of a chemical–mechanical polishing (CMP) process for surface preparation and device fabrication. , Unfortunately, this additional step not only poses the risk of introducing impurities or contaminants onto the polished surface but also makes it challenging to perform in-situ heterojunction growth. Among the various growth techniques for β-Ga 2 O 3 , MOCVD stands out as the most promising one due to its ability to produce high-quality crystalline thin films with high mobility and low compensation, which are crucial for realizing the theoretically predicted performance of β-Ga 2 O 3 devices. ,, When triethylgallium (TEGa) is employed as the Ga precursor in MOCVD, the typical growth rate of β-Ga 2 O 3 ranges from 0.2 to 1.0 μm/h. ,− MOCVD-grown vertical β-Ga 2 O 3 field plate Schottky barrier diodes have exhibited a low differential specific on-resistance of 0.67 mΩ·cm 2 and a breakdown electric field of 2.42 MV/cm . However, the limited thickness of the drift layer (1.1 μm) poses a constraint on the breakdown voltage.…”