Precision Recess of AlGaN/GaN with Controllable Etching Rate Using ICP-RIE Oxidation and Wet Etching
R. Sokolovskij (TU Delft - Electronic Components, Technology and Materials, TU Delft - Beijing Delft Institute of Intelligent Science and Technology)
J. Sun (Beijing Research Center)
F. Santagata (Peking University, Guangdong Dongguan Quality Supervision Testing Center)
E Iervolino (Peking University, Guangdong Dongguan Quality Supervision Testing Center)
S. Li (Peking University)
G.Y. Zhang (Peking University)
Pasqualina Sarro (TU Delft - Electronic Components, Technology and Materials)
Guo-Qi Zhang (TU Delft - Electronic Components, Technology and Materials)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
A method for highly controllable etching of AlGaN/GaN for the fabrication of high sensitivity HEMT based sensors is developed. The process consists of cyclic oxidation of nitride with O2 plasma using ICP-RIE etcher followed by wet etching of the oxidized layer. Previously reported cyclic oxidation-based GaN etching obtained very slow etching rate (∼0.38nm/cycle), limited by oxidation depth. The proposed approach allows fine control of the oxidation enabling the formation of accurately controlled recess of very thin (20∼30nm) barrier layers. With optimized power settings, etch rates from ∼0.6 to ∼11nm/cycle were obtained. AFM results did not show any increase in surface roughness after etching, indicating that surface quality of the etched layer was not affected by the etching process.
help_outline