Browsing by Author "Wang, H. C."

Now showing 1 - 4 of 4

First Experimental Demonstration of Negative Capacitance InGaAs MOSFETs With Hf0.5Zr0.5O2 Ferroelectric Gate Stack
(2018-01-01)
Luc, Q. H.
;
Fan-Chiang, C. C.
;
Huynh, S. H.
;
Huang, P.
;
Do, H. B.
We demonstrate, for the first time, the negative capacitance (NC) In0.53Ga0.47As nMOSFET with 8-nm Hf0.5Zr0.5O2 (HZO) as ferroelectric (FE) dielectric for sub-60 mV/dec subthreshold swing (SS). The impact of annealing treatments on the FE properties and electrical characteristics of NC InGaAs nMOSFETs are investigated. Optimized annealing condition results in NC effects at the HZO/Al2O3/InGaAs nMOSFETs with steep SS property (similar to 11 mV/dec).
Growth Parameters Optimization of GaN High Electron Mobility Transistor Structure on Silicon Carbide Substrate
(2014-01-01)
Wong, Y. Y.
;
Huang, S. C.
;
Huang, W. C.
;
Lumbantoruan, F.
;
Chiu, Y. S.
High electron mobility transistors heterostructures of AlGaN/GaN were grown by metalorganic chemical vapor deposition system on silicon carbide substrate. The growth parameters such as AlN buffer thickness, AlN spacer growth time and Al content in AlGaN barrier layer were optimized. Moreover, the effects of chamber pressure and V/III ratio at the initial growth state of GaN on film crystal quality were also investigated. The optimized AlGaN/GaN heterostructure has AlN buffer thickness of 120 nm, AlN spacer growth time of 10 s and Al content of 28% in the barrier layer. Furthermore, as a result of using higher chamber pressure and lower V/III, both the GaN crystal quality and electron mobility in the AlGaN/GaN were also significantly improved. After the growth parameter optimization, the GaN (002) and (102) planes exhibited X-ray rocking curve widths of 209 arcsec and 273 arcsec, respectively. Besides, the AlGaN/GaN structure also has an electron mobility of 1832 cm(2)/V-s and a sheet electron density of 1.08 10(13) cm(-2), which yielding a sheet resistance of 316 Omega/sq.
Low Leakage Current GaN MIS-HEMT with SiNx Gate Insulator using N-2 Plasma Treatment
(2013)
Liu, S. C.
;
Wang, H. C.
;
Chang, E. Y.
;
材料科學與工程學系
;
Department of Materials Science and Engineering
In this work, an effective N-2 plasma treatment for suppressing leakage current in GaN MIS-HEMT has been demonstrated. We observed an important issue of leakage current from the SiNx/GaN interface. To investigate the leakage current mechanisms, we measured the leakage current from all the possible paths in the device structure, such as gate, mesa isolation, and drain leakage. The current-voltage measurement results reveal a severe leakage path at the SiNx/GaN interface after SiNx deposited on the GaN surface without N-2 plasma treatment. By using N-2 plasma treatment, we succeed in suppressing the leakage current and effectively improve breakdown voltage. A significant performance improvement of GaN MIS-HEMT with very low leakage current has been achieved through the N-2 plasma treatment.
Slider dynamics with adhesive force in near-field recording
(2007-02-01)
Wang, H. C.
;
Huang, M. S.
;
Liu, T. S.
;
機械工程學系
;
Department of Mechanical Engineering
A near-field optical disk drive uses near-field optics to read/write disk data at a flying height of about 50 nm. Effects of interfacial adhesive forces, including van der Waals forces and electrostatic forces, become more evident during ultralow flying. However, the pickup head-flying-height variation is affected by the suspension, disk flutter, and air flow between the flying head and disk. An analysis model consisting of a simplified suspension and an air-bearing model with springs and dampers in three directions (focusing, pitching, and rolling) is used to simulate the dynamic behavior of the flying head. This study proposes an improved method for measuring the slider's flying-height variation. Simulation results with and without interfacial adhesive forces are compared.