Abstract The impact of plasma etching on the formation of low-resistance n-contacts on the AlGaN:Si current spreading layer during the chip fabrication of ultraviolet light-emitting diodes (UV LEDs) emitting at 265 nm is investigated. A two-step plasma etching process with a first rapid etching using BCl₃/Cl₂ gas mixture and a second slow etching step using pure Cl₂ gas has been developed. The etching sequence provides smooth mesa side-walls and an n-AlGaN surface with reduced surface damage. Ohmic n-contacts with a contact resistivity of 3.5 × 10⁻⁴ Ωcm² are obtained on Si-doped Al_0.65Ga_0.35N layers and the operating voltages of the UVC LEDs were reduced by 2 V for a current of 20 mA.