Associate Professor Hao Lu
Xidian University, China
Title: High-Power Density III-Nitride Semiconductor Materials and Device Technology
Abstract:
With the continuous advancement of wireless communication infrastructure, active devices represented by power amplifiers are increasingly demanded to deliver superior power handling capability. Group III-nitride materials, with gallium nitride (GaN) as the core representative, possess inherent superior semiconductor properties including a wide bandgap, high breakdown electric field, and high carrier density. Nevertheless, the full potential of their power performance is severely restricted by critical issues such as channel electron spillover, current collapse, and inadequate thermal management. Addressing these bottlenecks requires targeted and effective solutions based on intrinsic semiconductor material optimization and advanced device fabrication technologies.
This presentation focuses on high power density implementation via innovative semiconductor material design and device technological improvements. For millimeter-wave band applications, an ultra-thin InGaN channel structure is adopted to enhance carrier confinement in the channel region. Large-signal power measurements at 30 GHz demonstrate that the fabricated device achieves a high saturation power density (Psat) of 9.6 W/mm at a drain-source voltage (VDS) of 28 V, along with a peak power-added efficiency (PAE) of 48.54% at VDS = 14 V. For 10 GHz operation, an ultra-thin AlN buffer layer is proposed to suppress the residual iron doping tail effect induced by traditional doped buffer structures. Notably, without adopting any field-plate design, the proposed device realizes a record-breaking output power density (Pout) of 33.1 W/mm and a maximum PAE of 62.9% in the X-band, under optimal tuning conditions for power and efficiency performance, respectively.
Biography:
Hao Lu is currently an associate professor at Xidian University, China. He received the Ph.D. degree in electrical engineering from Xidian University, Xi'an, China. He has been engaged in the research of GaN-based microwave/millimeter wave electronic devices and key technologies of heterogenous integration. He has published over 60 technical papers in IEEE Electron Devices Letters, IEEE Transactions on Electron Devices, Applied Physics Letters, IEDM, etc., and 33 chinese filed/pending patents. He has made several oral reports at international conferences such as IEEE WiPDA, IEEE ICTA, IWN, APWS, CSW etc. In 2021, he won the IEEE WiPDA-Asia Best Presentation Award, AMSE Best Presentation Award, and Xidian Excellent Doctoral Dissertation Funding. Dr. Lu is Member of IEEE, China Institute of Electronics (CIE), and Chinese Physical Society (CPS).
His specific research interests include the advanced fabrication, characterization, and heterogenous integration of wide band-gap semiconductor electronic devices.