Low-Frequency Contact Noise of GaN Nanowire Device Detected by Cross-Spectrum Technique.
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Date
2011-06-01
Authors
L.-C. Li
K.-H. Huang
J.-A. Wei
Y.-W. Suen
T.-W. Liu
Chia-Chun Chen
L.-C. Chen
K.-H. Chen
Journal Title
Journal ISSN
Volume Title
Publisher
Japan Society of Applied Physics
Abstract
We report the properties of low-frequency contact noise of multielectrode GaN nanowire (NW) devices. A two-port cross-spectrum technique is used to discriminate the noise of the ohmic contact from that of the NW section. The diameter of the GaN NW is around 100 nm. The Ti/Al electrodes of the NWs are defined by e-beam lithography. The typical resistance of a NW section with a length of 800 nm is about 5.5 kΩ and the two-wire resistance is below 100 kΩ. The results show that the low-frequency excess noise of the GaN NW is much smaller than that of the current-flowing contact, indicating that the contact noise dominates the noise behavior in our GaN NW devices. A careful study of the noise amplitude (A) of the 1/f noise of different types of NW and carbon nanotube devices, both in our work and in the literature, yields an empirical formula for estimating A from the two-wire resistance of the device.