Gallium Oxide is a promising next-generation semiconductor material, but its practical application has been hindered by a significant challenge: achieving stable p-type control. A recent breakthrough from Nagoya University has changed the game, successfully achieving this crucial control and paving the way for the widespread use of gallium oxide in power devices.
The team at Nagoya University developed an innovative low-temperature plasma technology to overcome this hurdle. Their method involves a multi-step process. First, they used ion implantation to introduce nickel (Ni) into the gallium oxide material. Following this, the material was subjected to heat treatment at 300°C under oxygen radical irradiation, which facilitated the formation of nickel oxide (NiO), the key p-type dopant.
The final and critical step involved a rapid thermal annealing process at a high temperature of 950°C in an oxygen atmosphere. This process effectively integrated the nickel oxide as an acceptor within the gallium oxide crystal lattice, successfully forming a stable p-type region. This method is a significant departure from conventional techniques and offers remarkable advantages.
To validate their findings, the researchers fabricated a pn diode using this new technology. The results were impressive: the prototype device yielded twice the current compared to devices made with conventional methods. More importantly, the process demonstrated high reproducibility and stability, which are critical factors for mass production and commercialization.
This breakthrough is expected to be a cornerstone for the practical application of gallium oxide power devices. The technology is versatile and can be applied to various power device structures, while also boosting productivity. The ability to reliably create p-type gallium oxide opens up new possibilities for high-efficiency power electronics, which are vital for a sustainable future.
