Metal/BaTiO3/β-Ga2O3 dielectric heterojunction diode with 5.7 MV/cm breakdown field

Abstract

Wide and ultra-wide band gap semiconductors can provide excellent performance due to their high energy band gap, which leads to breakdown electric fields that are more than an order of magnitude higher than conventional silicon electronics. In materials where p-type doping is not available, achieving this high breakdown field in a vertical diode or transistor is very challenging.We propose and demonstrate the use of dielectric heterojunctions that use extreme permittivity materials to achieve high breakdown field in a unipolar device. We demonstrate the integration of a high permittivity material BaTiO3 with n-type β-Ga2O3 to enable 5.7 MV/cm average electric field and 7 MV/cm peak electric field at the device edge, while maintaining forward conduction with relatively low on-resistance and voltage loss. The proposed dielectric heterojunction could enable new design strategies to achieve theoretical device performance limits in wide and ultrawide band gap semiconductors where bipolar doping is challenging.

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

“…However, in fact, the breakdown events for all of the Ga 2 O 3 FETs and diodes reported so far were caused by their permanent failure due to electric field concentration at a gate or an anode electrode edge; therefore, the intrinsic E br of β-Ga 2 O 3 in terms of the avalanche breakdown has never been observed. For reference, the maximum E br experimentally derived from structural failure of a high-k dielectric/n-Ga 2 O 3 diode was ∼7 MV/cm [11].…”

β‐Gallium Oxide Devices: Progress and Outlook

“…The maximum reported so far is 7 MV cm −1 , which was extracted from given by permanent device failure. [ 5 ] For , it has been expected from theoretical calculation that the avalanche would be over 8 MV cm −1 . [ 6 ]…”

N-type doping of low-pressure chemical vapor deposition grown β-Ga2O3 thin films using solid-source germanium

“…This includes advances in growth [4][5][6][7] , fabrication 8,9 and understanding fundamental properties of β-Ga2O3 10,11 . Lateral and vertical devices with critical breakdown field exceeding SiC and GaN have been demonstrated experimentally 12,13 . Devices with power densities reaching as high as 1 GW/cm 2 14 and breakdown voltages up to 8 kV 8 were already realized.…”