Ultra-wide bandgap Ga2O3 technologies: benefits of heterogenous integration

Abstract

We discuss the potential of heterogenous integration of Ga2O3 with diamond for enabling energy-efficient kV-class power devices. The integration alleviates Ga2O3 material drawbacks such as its low thermal conductivity and inefficient hole conductivity. The benefits of heterogeneous integration are demonstrated through electrical and thermal simulations of a Ga2O3-Al2O3-diamond superjunction based Schottky barrier diode. The simulation studies show that the novel device has potential to break the RON-breakdown voltage limit of Ga2O3, while showing relatively low rise in temperature compared to conventional devices. First steps for the actual materials integration are taken with the epitaxial growth of Ga2O3 on single crystal diamond substrates.

Heterogenous integration of gallium oxide with diamond and SiC

“…Metal-Organic Chemical Vapor Deposition (MOCVD) was used with TEGa precursors and oxygen source (99.9999% pure O2 gas) to deposit thin films, with a growth rate of roughly 600 nm/hr. Details of the growth experiment has been provided in [6,7]. A (-201) -Ga2O3 film orientation was confirmed by X-ray diffraction (XRD).…”

“…Selecting materials with higher thermal conductivity would also address thermal management. Nickel Oxide has been explored as a p-type material and successful Gallium Oxide / Nickel Oxide high voltage proto-type devices have been demonstrated [5,6]. However, Nickel Oxide's has a low thermal conductivity, so enabling devices which can handle high current densities may be a challenge.…”

Investigation of high-performance Schottky diodes on a Ga2O3 epilayer using Cu with high barrier height, high temperature stability and repeatability

“…Today, β-Ga 2 O 3 , due to its ultrawide bandgap of ∼4.9 eV, high electric field strength of ∼8 MV cm −1 , and extremely high Baliga and Johnson figures of merit compared to other wide bandgap semiconductor materials, such as SiC and GaN, with high thermal and chemical stability, is emerging as a promising candidate for power device applications [1][2][3][4][5][6][7][8][9][10]. To date, several authors have extensively studied Schottky barrier diodes (SBDs), field effect transistors (FETs), and solar blind photodetectors based on β-Ga 2 O 3 due to the availability and ease of growth of high-quality single crystal substrates, homoepitaxy, and heteroepitaxy thin films via various meltgrowth and thin-film growth techniques [3,[11][12][13][14][15][16][17][18][19][20]. SBDs and FETs based on β-Ga 2 O 3 with breakdown voltages greater than 1 kV have been demonstrated [21].…”