國立臺灣師範大學化學系L.-C. LiK.-H. HuangJ.-A. WeiY.-W. SuenT.-W. LiuChia-Chun ChenL.-C. ChenK.-H. Chen2014-12-022014-12-022011-06-010021-4922http://rportal.lib.ntnu.edu.tw/handle/20.500.12235/42359We 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.