Self-Align-Gated GaN Field Emitter Arrays Sharpened by a Digital Etching Process
Pao-Chuan Shih, Girish Rughoobur, Kai Cheng, Akintunde I. Akinwande, Tomás Palacios
Abstract
Field emitters are attracting much attention recently because of their potential for high-frequency and harsh-environment applications. Although silicon is the most studied semiconductor for field emitters, III-Nitrides are also very promising thanks to their tunable electron affinities. Two main challenges exist for low turn-on-voltage III-Nitrides field emitters: lack of a self-aligned gate and tip-sharpening technologies. In this work, we demonstrate self-aligned-gated GaN field emitter arrays whose tips are sharpened by a wet-based digital etching technology. This technology allows to reduce the tip size from 40 nm down to 20 nm. Gated GaN field emitters with a turn-on voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GE,ON</sub> ) of 20 V and current density of 150 mA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GE</sub> = 50 V have been demonstrated.