The Reflectivity enhancement of Ni/Ag/(Ti or Mo)/Au Ohmic Contact for Flip-Chip Light-Emitting Diode Applications

Author

Chang, Liann-Be ; Shiue, Ching-Chuan ; Jeng, Ming-Jer

Author_Institution

Chang-Gung Univ., Taoyuan

fYear

2007

fDate

2-5 Oct. 2007

Firstpage

177

Lastpage

180

Abstract

The proposed multilayer structures Ni/Ag/M/Au, with blocking metal (M) of Ti and Mo, to form both ohmic and reflective contact for flip chip light emitting diode (FCLED) application, are fabricated. During the annealing process of conventional three-layer Ni/Ag/Au contacts, serious Au intermixing with Ag and Ni was found to result in poor reflectance (63% at the wavelength of 465 nm). It is found that the inserted (between Ni/Ag and Au) diffusion barrier (Ti or Mo) can block Au inter diffusion effectively and hence improves the correspondent FCLED reflectivity (as high as 93%).

Keywords

III-V semiconductors; annealing; chemical interdiffusion; diffusion barriers; gallium compounds; gold; light emitting diodes; mixing; molybdenum; nickel; ohmic contacts; optical multilayers; reflectivity; semiconductor thin films; silver; titanium; wide band gap semiconductors; FCLED reflectivity; GaN; GaN - Binary; Ni-Ag-Mo-Au; Ni-Ag-Mo-Au - Interface; Ni-Ag-Ti-Au; Ni-Ag-Ti-Au - Interface; Ohmic contact; annealing; blocking metal; diffusion barrier; flip-chip light-emitting diode applications; gallium nitride films; interdiffusion; intermixing; multilayer structures; reflective contact; semiconductor thin films; three-layer contacts; Annealing; Contact resistance; Gallium nitride; Gold; Light emitting diodes; Metallization; Ohmic contacts; Reflectivity; Solid state lighting; Surface resistance;

fLanguage

English

Publisher

ieee

Conference_Titel

Advanced Thermal Processing of Semiconductors, 2007. RTP 2007. 15th International Conference on

Conference_Location

Catania, Sicily

Print_ISBN

978-1-4244-1228-0

Electronic_ISBN

978-1-4244-1228-0

Type

conf

DOI

10.1109/RTP.2007.4383839

Filename

4383839