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.
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2017, Vol. 31 
