In the relentless pursuit of more efficient and reliable power electronics, researchers at the Institute of Electronics, National Yang Ming Chiao Tung University in Hsinchu, Taiwan, have made a significant breakthrough. Led by Yu-Ru Li, the team has developed a novel method to enhance the performance of lateral β-Ga2O3 Schottky barrier diodes (SBDs) using nitrogen thermal annealing. This advancement could pave the way for next-generation power devices, crucial for the energy sector’s ongoing transformation.
Beta-gallium oxide (β-Ga2O3) has emerged as a promising material for high-power electronics due to its wide bandgap and excellent electrical properties. However, the performance of β-Ga2O3-based devices has been hindered by high reverse leakage currents and premature breakdown, largely attributed to oxygen vacancies on the epilayer surface. These defects degrade the contact quality between the electrodes and β-Ga2O3, leading to reduced current conduction and reliability issues.
To tackle this challenge, Li and his team employed rapid thermal annealing (RTA) under nitrogen ambience. “The key to improving the performance of these diodes lies in reducing the oxygen vacancies,” Li explained. “By treating the devices with nitrogen annealing, we can significantly enhance the contact quality and minimize interface defects.”
The researchers fabricated lateral SBDs using metalorganic chemical vapor deposition (MOCVD) and deposited Ti/Al/Ni/Au layers as ohmic electrodes and Ni/Au layers as Schottky electrodes. They then subjected the devices to RTA treatment at temperatures ranging from 550°C to 750°C for 60 seconds. The results were striking: the on-off current ratio improved from 5.56 × 104 to 1.30 × 107, and the breakdown voltage increased from 173 V to 263 V.
The implications of this research are far-reaching for the energy sector. High-performance β-Ga2O3-based power devices could enable more efficient power conversion, reduced energy losses, and enhanced reliability in various applications, from renewable energy integration to electric vehicles and grid infrastructure. “This technology has the potential to revolutionize the way we design and manufacture power electronics,” Li noted. “It brings us one step closer to a more sustainable and energy-efficient future.”
The study, published in the journal ‘Advanced Surface Science’ (English translation of ‘Applied Surface Science Advances’), underscores the importance of material engineering and thermal treatment in optimizing semiconductor devices. As the demand for advanced power electronics continues to grow, innovations like nitrogen thermal annealing will play a pivotal role in shaping the future of the energy sector.
The research not only highlights the potential of β-Ga2O3 but also sets a precedent for exploring similar treatments in other wide-bandgap materials. As the industry strives for higher efficiency and reliability, such breakthroughs will be instrumental in driving technological advancements and meeting the evolving needs of modern power systems. The work by Li and his team serves as a testament to the power of innovative thinking and meticulous research in pushing the boundaries of what is possible in semiconductor technology.