An Improved Ohmic Contact to n-Type N-Face GaN for Extremely Low Voltage-Operated Vertical Light Emitting Diodes

Author

Wang, Liancheng ; Guo, Enqing ; Liu, Zhiqiang ; Yi, Xiaoyan ; Wang, Guohong

Author_Institution

Lighting R&D Center, Chinese Acad. of Sci., Beijing, China

fYear

2011

fDate

16-18 May 2011

Firstpage

1

Lastpage

4

Abstract

Low resistance and thermally stable n-type contact to N-polar GaN is essentially important for vertical light emitting diodes (VLEDs) . In this paper, the difference of the contacts deposited on wet-etching roughed and un-roughed surface was investigated. It was found that VLEDs with contacts deposited on roughed surface exhibits lower leakage currents yet higher operating voltage. Based on this, a new scheme for depositing metallization contacts has been developed. VLEDs fabricated based on this scheme shows extremely low operating voltage (2.75V@350mA), low reverse leakage current (0.015μA@-5V). There is no optical output compromise and aging test further confirmed its stability.

Keywords

III-V semiconductors; electrical resistivity; etching; gallium compounds; leakage currents; light emitting diodes; metallisation; ohmic contacts; surface roughness; thermal stability; wide band gap semiconductors; GaN; current 350 mA; electrical resistance; low voltage-operated vertical light emitting diodes; metallization contacts; ohmic contact; operating voltage; reverse leakage current; thermally stable n-type N-face contact; voltage 2.75 V; voltage 5 V; wet-etching roughed surface; wet-etching unroughed surface; Conductivity; Contacts; Gallium nitride; Rough surfaces; Surface morphology; Surface roughness; Surface treatment;

fLanguage

English

Publisher

ieee

Conference_Titel

Photonics and Optoelectronics (SOPO), 2011 Symposium on

Conference_Location

Wuhan

ISSN

2156-8464

Print_ISBN

978-1-4244-6555-2

Type

conf

DOI

10.1109/SOPO.2011.5780596

Filename

5780596