Gallium Nitride (GaN) High-Electron-Mobility Transistors with Thick Copper Metallization Featuring a Power Density of 8.2 W/mm for Ka-Band Applications

Y C Lin; S H Chen; P H Lee; K H Lai; T J Huang; Edward Y Chang; Heng-Tung Hsu

doi:10.3390/mi11020222

Gallium Nitride (GaN) High-Electron-Mobility Transistors with Thick Copper Metallization Featuring a Power Density of 8.2 W/mm for Ka-Band Applications

Micromachines (Basel). 2020 Feb 21;11(2):222. doi: 10.3390/mi11020222.

Authors

Y C Lin¹, S H Chen², P H Lee², K H Lai², T J Huang³, Edward Y Chang³, Heng-Tung Hsu³

Affiliations

¹ Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan.
² Department of Electronics Engineering, National Chiao Tung University, Hsinchu 300, Taiwan.
³ International College of Semiconductor Technology, National Chiao Tung University, Hsinchu 300, Taiwan.

Abstract

Copper-metallized gallium nitride (GaN) high-electron-mobility transistors (HEMTs) using a Ti/Pt/Ti diffusion barrier layer are fabricated and characterized for Ka-band applications. With a thick copper metallization layer of 6.8 μm adopted, the device exhibited a high output power density of 8.2 W/mm and a power-added efficiency (PAE) of 26% at 38 GHz. Such superior performance is mainly attributed to the substantial reduction of the source and drain resistance of the device. In addition to improvement in the Radio Frequency (RF) performance, the successful integration of the thick copper metallization in the device technology further reduces the manufacturing cost, making it extremely promising for future fifth-generation mobile communication system applications at millimeter-wave frequencies.

Keywords: copper metallization; high-electron-mobility transistors; millimeter wave.