Improvement of GaN plasma etching uniformity by optimizing the coil electrode with plasma simulation and experimental validation

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

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Detail(s)

Original languageEnglish
Article number126252
Number of pages10
Journal / PublicationSurface and Coatings Technology
Volume400
Online published1 Aug 2020
Publication statusPublished - 25 Oct 2020

Abstract

GaN-based semiconductor devices such as LEDs and power electronic devices are widely used but device fabrication can be further optimized by improving the uniformity and throughput. In inductively-coupled plasma (ICP) etching, the coil can be optimized to produce a tunable plasma distribution to improve the etching uniformity. Different from planar coils, the dual spiral decreases the electric field and magnetic field coupling between the inner and outer coils by enlarging the space without changing the equipment. The vertically arranged coils in each group can independently control plasma generation in the separate zone and tunable etching uniformity can be achieved by varying the power supplied to the inner and outer coils. The etching uniformity is improved from 5.83% to 2.95% based on maximum-minus-minimum (M-N) calculation and from 3.93% to 1.42% with the average value calculated by using the optimized coil structure. Plasma simulation and experiments confirm the source of etching non-uniformity and the knowledge is important to the fabrication of GaN-based and other devices, especially large-scale industrial production requiring low cost and 450 mm wafer capability.

Research Area(s)

  • Field coupling, GaN, Inductively-coupled plasma, Plasma etching, Plasma simulation, Uniformity

Citation Format(s)

Improvement of GaN plasma etching uniformity by optimizing the coil electrode with plasma simulation and experimental validation. / Xiao, Dezhi; Ruan, Qingdong; Liu, Liangliang; Shen, Jie; Cheng, Cheng; Chu, Paul K.

In: Surface and Coatings Technology, Vol. 400, 126252, 25.10.2020.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal