First Demonstration of State-of-the-art GaN HEMTs for Power and RF Applications on A Unified Platform with Free-standing GaN Substrate and Fe/C Co-doped Buffer
Mei Wu, Meng Zhang, Ling Yang, Bin Hou, Qian Yu, Shiming Li, Chunzhou Shi, Wei Zhao, Hao Lu, Weiwei Chen, Qing Zhu, Xiaohua Ma, Yue Hao
Abstract
In this paper, we report excellent power and radio frequency (RF) performances of GaN HEMTs grown on free-standing GaN substrate using a unified Fe/C co-doped GaN buffer. With gate-drain distance ($L_{\mathrm{gd}}$) of 6.35 $\mu$m, the device presented a low specific on-resistance ($R_{\mathrm{on}_{-}\mathrm{sp}}$) of 0.66 m$\Omega\cdot\mathrm{cm}^{2}$ and a high breakdown voltage ($V_{\mathrm{BR}}$) of 710 V. Record Johnson’s figure-of-merit (JFOM) of 16.25 THz$\cdot$V and $f_{\max}$. VBR of 38.34 THz$\cdot$V were achieved among GaN HEMTs. Load-pull measurements reveal a state-of-the-art power density of 10.2 W/mm for GaN-on-GaN HEMTs. Moreover, the GaN-on-GaN HEMTs in this work show excellent reliability and stable Schottky characteristics after the reverse gate step stress. This technology provides a unified design of material and process for GaN power and RF devices with high performance, promoting the integration of GaN-based devices on the same platform.