Copper gate AlGaN/GaN HEMT with low gate leakage current
- 4 August 2003
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Electron Device Letters
- Vol. 24 (8) , 500-502
- https://doi.org/10.1109/led.2003.815158
Abstract
Copper (Cu) gate AlGaN/GaN high electron mobility transistors (HEMTs) with low gate leakage current were demonstrated. For comparison, nickel/gold (Ni/Au) gate devices were also fabricated with the same process conditions except the gate metals. Comparable extrinsic transconductance was obtained for the two kinds of devices. At gate voltage of -15 V, typical gate leakage currents are found to be as low as 3.5×10/sup -8/ A for a Cu-gate device with gate length of 2 μm and width of 50 μm, which is much lower than that of Ni/Au-gate device. No adhesion problem occurred during these experiments. Gate resistance of Cu-gate is found to be about 60% as that of NiAu. The Schottky barrier height of Cu on n-GaN is 0.18 eV higher than that of Ni/Au obtained from Schottky diode experiments. No Cu diffusion was found at the Cu and AlGaN interface by secondary ion mass spectrometry determination. These results indicate that copper is a promising candidate as gate metallization for high-performance power AlGaN/GaN HEMT.Keywords
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