| RESEARCH PAPER |
|
|
|
|
|
| Ohmic Contact of Ti/Al/Ni/Au on N-polar GaN |
| WANG Xianbin1, WANG Yingli1, ZHAO Zhengping2
|
1 College of Physical and Electrical Information Engineering, Shijiazhuang University, Shijiazhuang 050000;
2 College of Information Engineering, Hebei University of Technology, Tianjin 300130 |
|
|
|
|
Abstract N-polar GaN and ohmic contact on it have received more attentions for its unique material properties and chemical activity. Using Ti/Al/Ni/Au as ohmic contact metals, optimal annealing conditions and interfacial reactions between metals and N-polar GaN were studied by cross-section transmission electron microscopy (TEM) and energy dispersive X ray energy spectrometer (EDX). Results showed that when the annealing temperature was increased to 860 ℃, the optimal specific contact resistivity ρc was 1.7×10-5 Ω·cm2. TEM and EDX analyses showed that, in addition to reported AlN, polycrystalline AlOx were founded at the interface. They both increase the height of potential barrier and result in adverse effects on ohmic contact on N-polar GaN.
|
|
Published: 25 February 2017
Online: 2018-05-02
|
|
|
|
|
1 Iucolano F, Greco G, Roccaforte F. Correlation between microstructure and temperature dependent electrical behavior of annealed Ti/Al/Ni/Au ohmic contacts to AlGaN/GaN heterostructures[J]. Appl Phys Lett,2013,103(20):201604.
2 Chiu Y S, Lin T M, Nguyen H Q, et al. Ti/Al/Ti/Ni/Au ohmic contacts on AlGaN/GaN high electron mobility transistors with improved surface morphology and low contact resistance[J]. J Vacuum Sci Technol B,2014,32(1):011216.
3 Kong X, Wei K, Liu G, et al. Role of Ti/Al relative thickness in the formation mechanism of Ti/Al/Ni/Au ohmic contacts to AlGaN/GaN heterostructures[J]. J Phys D: Appl Phys,2012,45(26):265101.
4 Zhou L, Johnson M R, Smith D J, et al. Microstructure of Ti/Al/Ni/Au ohmic contacts for N-polar GaN/AlGaN high electron mobility transistor devices[J].J Vacuum Sci Technol B,2014,32(1):011201.
5 Feng Z H, Wang X B, Li W, et al. Ti/Al based ohmic contact to as-grown N-polar GaN [J]. Chin Phys Lett,2015,32(8):087102.
6 Wang L, Mohammed F M, Adesida I. Characterization of Au and Al segregation layer in post-annealed thin Ti/Al/Mo/Au ohmic contacts to n-GaN[J]. J Appl Phys,2005,98(10):106105.
|
|
|
|
渝公网安备50019002502923号 © Editorial Office of Materials Reports.
2017, Vol. 31 
