130 mA mm⁻¹ β-Ga₂O₃ metal semiconductor field effect transistor with low-temperature metalorganic vapor phase epitaxy-regrown ohmic contacts

Abstract

We report on the first demonstration of metalorganic vapor phase epitaxy-regrown (MOVPE) ohmic contacts in an all MOVPE-grown β-Ga 2 O 3 metal semiconductor field effect transistor (MESFET). The low-temperature (600 °C) heavy (n + ) Si-doped regrown layers exhibit extremely high conductivity with a sheet resistance of 73 Ω/□ and a record low metal/n + -Ga 2 O 3 contact resistance of 80 mΩ•mm and specific contact resistivity of 8.3 × 10 −7 Ω•cm 2 were achieved. The fabricated MESFETs exhibit a maximum ON current of 130 mA mm −1 and a high I ON /I OFF ratio of >10 10 . Thermal characterization was also performed to assess the device self-heating under the high current and power conditions.

β-Ga2O3 material properties, growth technologies, and devices: a review

“…It should be noted that Ti-based electrodes formed on n-Ga 2 O 3 can provide ohmic characteristics only in case of n > 10 18 cm −3 ; therefore, formation of n + -Ga 2 O 3 is absolutely necessary to fabricate ohmic contacts. Si-ion implantation doping and regrowth have been utilized to form n + -Ga 2 O 3 ohmic regions [52,59,60]. The post-metallization annealing provides short-range intermixing of Ti and Ga 2 O 3 at the interface, resulting in further reduction in contact resistance and improvement in reliability and endurance [61][62][63].…”

β-Ga₂O₃ Lateral High-Permittivity Dielectric Superjunction Schottky Barrier Diode With 1.34 GW/cm² Power Figure of Merit

“…After the growth of the epilayer, 500 nm deep rectangular trenches of different lengths and widths were patterned using photolithography followed by BCl 3 based Inductively coupled plasma (ICP) reactive ion etching (RIE) with an etch rate of ∼12 nm/min. After the trench definition, ohmic contact recess etching was performed using BCl 3 based ICP RIE and n + ohmic contact with doping concentration of approximately 1.4×10 20 cm −3 was then regrown using MOVPE [32], [33] a SiO 2 regrowth mask. 300 nm thick BaTiO 3 was then deposited on the sample using RF sputtering at room temperature in oxygen ambient with O 2 /Ar ratio of 1:10 and at a sputter power of 140 W and chamber pressure of 5mTorr [34] as shown in Fig.…”

β-Ga2O3Lateral High-Permittivity Dielectric Superjunction Schottky Barrier Diode With 1.34 GW/cm2Power Figure of Merit

“…After the growth of the epilayer, 500 nm deep rectangular trenches of different lengths and widths were patterned using photolithography followed by BCl 3 based Inductively coupled plasma (ICP) reactive ion etching (RIE) with an etch rate of ∼12 nm/min. After the trench definition, ohmic contact recess etching was performed using BCl 3 based ICP RIE and n + ohmic contact with doping concentration of approximately 1.4×10 20 cm −3 was then regrown using MOVPE [32], [33] using a SiO 2 regrowth mask. 300 nm thick (T D ) BaTiO 3 was then sputter deposited on the sample in oxygen ambient at room temperature [34] as shown in Fig.…”