Multiple Ti/Al stacks induced thermal stability enhancement in Ti/Al/Ni/Au Ohmic contact on AlGaN/GaN heterostructure

Author

Dong, Zhihua ; Wang, Jinyan ; Gong, Rumin ; Liu, Shenghou ; Wen, C.P. ; Yu, Min ; Xu, Fujun ; Hao, Yilong ; Shen, Bo ; Wang, Yangyuan

Author_Institution

Inst. of Microelectron., Peking Univ., Beijing, China

fYear

2010

Firstpage

1359

Lastpage

1361

Abstract

Compared with Ti/Al/Ni/Au Ohmic contacts, Ti/Al/Ti/Al/Ti/Al/Ti/Al/Ti/Al/Ni/Au with multiple Ti/Al stacks improved the thermal stability. Multiple-stacked Ohmic contacts showed lower degradation during long-time thermal aging at 600°C. The samples after degradation were tested with Transmission Electron Microscopy (TEM) to research the structural reasons. TEM results show that multiple stacks can avoid the producing of voids, which usually appear in the single Ti/Al stacked Ohmic metals. Al-Au alloy is believed to be the origin of the voids. While multiple Ti/Al stacks can reduce the size and quantity of Al-Au alloy and thus avoid the appearance of voids. The thermal stability enhancement of Ti/Al/..../Ti/Al/Ni/Au Ohmic contacts rendered it a great application in high temperature AlGaN/GaN HEMTs.

Keywords

aluminium alloys; gallium compounds; gold alloys; nickel alloys; ohmic contacts; thermal stability; titanium alloys; transmission electron microscopy; AlGaN-GaN; TEM; Ti-Al-Ni-Au; multiple-stacked ohmic contacts; temperature 600 degC; thermal stability enhancement; transmission electron microscopy; Aging; Aluminum gallium nitride; Gallium nitride; Gold; Ohmic contacts; Thermal stability; AlGaN/GaN; Ohmic contact; Ti/Al; multiple stacks; thermal stability;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State and Integrated Circuit Technology (ICSICT), 2010 10th IEEE International Conference on

Conference_Location

Shanghai

Print_ISBN

978-1-4244-5797-7

Type

conf

DOI

10.1109/ICSICT.2010.5667648

Filename

5667648