Browsing by Author "Su, Yung-Hsuan"

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Effect of Low Temperature Ge Seed Layer and Post Thermal Annealing on Quality of Ge1-xSix (0.05 <= x <= 0.1) Graded Buffer Layers by UHV-CVD
(2014-07-01)
Chi-Lang Nguyen
;
Nguyen Hong Quan
;
Binh-Tinh Tran
;
Su, Yung-Hsuan
;
Tang, Shih-Hsuan
High crystal quality, smooth surface and fully relaxed Ge1-xSix (0.05 <= x <= 0.1) buffers are grown on 6 degrees-off (100) Si substrate by UHV-CVD. A low-temperature (LT) Ge seed layer is used to improve the quality of the Ge1-xSix buffers. In this study, the LT-Ge seed layer is deposited directly onto the Si substrate at a low temperature of 315 degrees C. After that, stress-free Si0.1Ge0.9 and Si0.05Ge0.95 layers are grown, respectively. An in-situ annealing process is also performed for the Si0.1Ge0.9/LT-Ge layers to increase the degree of relaxation. The total thickness of the epitaxial layer is 270 nm, with the average surface roughness at 0.6 nm.
High Quality Ge Epitaxial Films Grown on In0.51Ga0.49P/GaAs and GaAs Substrates by Ultra High Vacuum Chemical Deposition
(2014-01-01)
Su, Yung-Hsuan
;
Tang, Shih-Hsuan
;
Nguyen, Chi Lang
;
Kuan, Ching-Wen
;
Yu, Hung-Wei
The epitaxial growth of high quality Ge thin films on different materials of In0.51Ga0.49P and GaAs by ultra high vacuum chemical vapor deposition (UHVCVD) system was studied. The crystallinity of high quality Ge layers on In0.51Ga0.49P and GaAs layers can be proved by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The comparison of surface morphology between Ge grown on In0.51Ga0.49P and GaAs was also analyzed by atomic force microscopy (AFM). The roughness of Ge on GaAs shows better than that of In0.51Ga0.49P. Both of these structures were designed for fabricating p-channel metal-oxide-semiconductor field-effect transistor (MOSFET) for the integration of Ge p-channel device with III-V n-channel electronic device.
High quality Ge thin film grown by ultrahigh vacuum chemical vapor deposition on GaAs substrate
(2011-04-18)
Tang, Shih-Hsuan
;
Chang, Edward Yi
;
Hudait, Mantu
;
Maa, Jer-Shen
;
Liu, Chee-Wee
High-quality epitaxial Ge films were grown on GaAs substrates by ultrahigh vacuum chemical vapor deposition. High crystallinity and smooth surface were observed for these films by x-ray diffraction, transmission electron microscopy, and atomic force microscopy. Direct band gap emission (1550 nm) from this structure was detected by photoluminescence. Valence band offset of 0.16 eV at the Ge/GaAs interface was measured by x-ray photoelectron spectroscopy. N-type arsenic self-doping of 10(18)/cm(-3) in the grown Ge layers was determined using electrochemical capacitance voltage measurement. This structure can be used to fabricate p-channel metal-oxide-semiconductor field-effect transistor for the integration of Ge p-channel device with GaAs n-channel electronic device. (C) 2011 American Institute of Physics. [doi:10.1063/1.3580605]
InAs-Channel Metal-Oxide-Semiconductor HEMTs with Atomic-Layer-Deposited Al2O3 Gate Dielectric
(2009-01-01)
Chang, Chia-Yuan
;
Chang, Edward Yi
;
Huang, Wei-Ching
;
Su, Yung-Hsuan
;
Trinh, Hai-Dang
The performance of n-type metal-oxide-semiconductor HEMTs with an InAs-channel using atomic-layer-deposited Al2O3 as gate dielectric has been fabricated and evaluated. The device performances of a set of scaled transistors with different gate dielectric thicknesses of 3, 5 and 7 nm have been investigated to determine whether the architecture of Al2O3 dielectric on InAs-channel HEMT can demonstrate good properties at low bias conditions for high-speed, high performance CMOS applications. The results indicate that the high-performance InAs-channel MOS-HEMTs with an ALD Al2O3 gate dielectric are promising candidates for advanced post-Si CMOS applications.