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 BCl 3 /Cl 2 gas mixture and a second slow etching step using pure Cl 2 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 Ωcm 2 are obtained on Si-doped Al 0.65 Ga 0.35 N layers and the operating voltages of the UVC LEDs were reduced by 2 V for a current of 20 mA.

中文翻译：

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通过两步等离子刻蚀工艺，用于UVC LED的低电阻n触点

研究了在265 nm处发射的紫外发光二极管（UV LED）的芯片制造过程中，等离子体蚀刻对AlGaN：Si电流扩散层上低电阻n接触形成的影响。已经开发出一种两步等离子体刻蚀工艺，其中第一步使用BCl 3 / Cl 2气体混合物进行快速刻蚀，第二步使用纯Cl 2气体进行缓慢刻蚀。蚀刻顺序提供了光滑的台面侧壁和n-AlGaN表面，减少了表面损伤。在掺杂Si的Al 0.65 Ga 0.35 N层上获得电阻率为3.5×10 -4Ωcm2的欧姆n接触，并且在20 mA电流下，UVC LED的工作电压降低了2V。