Browsing by Author "Lee, M. W."

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Correlated Electric Fluctuations in GaN Nanowire Devices
(2009-02-01)
Li, L. C.
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Huang, S. Y.
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Wei, J. A.
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Suen, Y. W.
;
Lee, M. W.
We report an experimental study on the correlation spectrums between different sections of a multicontact GaN nanowire device. Our results indicate that there exists a negative correlation between the voltage fluctuations of adjacent sections of the nanowire separated by a metal contact in the transition region between the low-frequency 1/f noise and the high-frequency white thermal noise. We suggest that this correlation is caused by the voltage fluctuation under the contact area.
Study of Enhancement-Mode Tri-Gate InAs HEMTs for Low Noise Application
(2019-01-01)
Wang, C.
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Lin, Y. C.
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Kuo, C. N.
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Lee, M. W.
;
Yao, J. N.
An enhancement-mode tri-gate InAs HEMT is investigated for low noise application in this paper. The 3-D tri-gate structure is sidewall-gate-metal connected to InAlAs layers, the gate connection to the InAlAs layers increases their potential to the positive direction with increasing the gate bias, resulting gate control ability enhancement. Compared with planar device, the tri-gate device shows high transconductance and low noise figure. The enhancement-mode tri-gate device exhibits excellent low noise figure with less than 3.5 dB when the device operation frequency range of 18 GHz to 50 GHz.
Study of Thick Copper Metallization with WNx as Diffusion Barrier for AlGaN/GaN HEMTs
(2019-01-01)
Lin, Y. C.
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Lee, M. W.
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Tsai, M. Y.
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Wang, C.
;
Yao, J. N.
In this study, the thick copper metallization with WNx as diffusion barrier is investigated for AlGaN/GaN HEMTs. The device current density, transconductance, ft, fmax, noise figure were evaluated for the device with and without thick copper interconnect metal, and the thermal stability test was performed after the device with copper metallization.
Temperature dependence of the excess noise of a GaN nanowire device
(2007)
Li, L. C.
;
Huang, S. Y.
;
Wei, J. A.
;
Suen, Y. W.
;
Lee, M. W.
We report on the study of the low-frequency excess noise of a GaN nanowire (NW) device from room temperature to 135 K. A Lorentzian noise is found to be embedded in the 1/f noise background, and becomes more significant as the bias current increases or the temperature decreases. The temperature dependance of the associated characteristic time, extracted from the spectrum, shows two thermally activated regions with different activation energies, which originate from different carrier-trapping levels in the NW device. The temperature dependence of the 1/f noise is difficult to unveil due to the presence of the strong Lorentzian noise.