Abstract
The optimization of mesa etch for a quasi-vertical gallium nitride (GaN) Schottky barrier diode (SBD) by inductively coupled plasma (ICP) etching was comprehensively investigated in this work, including selection of the etching mask, ICP power, radio frequency (RF) power, ratio of mixed gas, flow rate, and chamber pressure, etc. In particular, the microtrench at the bottom corner of the mesa sidewall was eliminated by a combination of ICP dry etching and tetramethylammonium hydroxide (TMAH) wet treatment. Finally, a highly anisotropic profile of the mesa sidewall was realized by using the optimized etch recipe, and a quasi-vertical GaN SBD was demonstrated, achieving a low reverse current density of 10−8 A/cm2 at −10 V.
Highlights
As a wide-bandgap semiconductor material, gallium nitride (GaN) has attracted increasing attention in recent years, attributed to its superior material properties such as wide bandgap, high electron saturation velocity, and high critical electric field [1]
The leakage current path along the etched sidewall can be reduced by optimization of the etching technique or combination with further surface treatment to reduce plasma damage, leading to improvement of the device breakdown voltage (BV)
The steep profile of the mesa sidewall allows for reduction of the distance between the anode and cathode electrodes, resulting in a reduction of the series resistance of the Schottky barrier diode (SBD)
Summary
As a wide-bandgap semiconductor material, gallium nitride (GaN) has attracted increasing attention in recent years, attributed to its superior material properties such as wide bandgap, high electron saturation velocity, and high critical electric field [1]. 2 In this paper, we focus on the optimization of the mesa sidewall process to achieve steep, microtrench-free, and low-damage sidewalls, including mask selection, ICP power, RF power, mixed etching gas ratio, flow rate, chamber pressure, etc.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
