Browsing by Author "Huynh, Sa Hoang"

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Effect of Two-Step Metal Organic Chemical Vapor Deposition Growth on Quality, Diameter and Density of InAs Nanowires on Si (111) Substrate
(2018-02-01)
Yu, Hung Wei
;
Anandan, Deepak
;
Hsu, Ching Yi
;
Hung, Yu Chih
;
Su, Chun Jung
High-density (similar to 80/um(2)) vertical InAs nanowires (NWs) with small diameters (similar to 28 nm) were grown on bare Si (111) substrates by means of two-step metal organic chemical vapor deposition. There are two critical factors in the growth process: (1) a critical nucleation temperature for a specific In molar fraction (approximately 1.69 x 10(-5) atm) is the key factor to reduce the size of the nuclei and hence the diameter of the InAs NWs, and (2) a critical V/III ratio during the 2nd step growth will greatly increase the density of the InAs NWs (from 45 mu m(-2) to 80 mu m(-2)) and at the same time keep the diameter small. The high-resolution transmission electron microscopy and selected area diffraction patterns of InAs NWs grown on Si exhibit a Wurtzite structure and no stacking faults. The observed longitudinal optic peaks in the Raman spectra were explained in terms of the small surface charge region width due to the small NW diameter and the increase of the free electron concentration, which was consistent with the TCAD program simulation of small diameter (< 40 nm) InAs NWs.
Growth of high-quality In0.28Ga0.72Sb/AlSb/GaSb/GaAs heterostructure by metalorganic chemical vapor deposition for single-channel Sb-based complementary metal-oxide-semiconductor applications
(2017-07-01)
Huynh, Sa Hoang
;
Ha, Minh Thien Huu
;
Do, Huy Binh
;
Nguyen, Tuan Anh
;
Yu, Hung Wei
The growth of high-quality In0.28Ga0.72Sb epilayer on an AlSb/GaSb/GaAs heterostructure by metalorganic chemical vapor deposition is demonstrated. The In0.28Ga0.72Sb epilayer has a fully relaxed surface roughness of similar to 1.0nm and a low threading dislocation density of similar to 6.2 x 10(6)cm(-2). The valence band offset (VBO) of 3.11 eV and conduction band offset (CBO) of 3.21 eV for an Al2O3/In0.28Ga0.72Sb interface extracted from X-ray photoemission spectroscopy data highlight its suitability for use in single-channel InGaSb-based complementary metal-oxide-semiconductor (CMOS) applications. The type-I straddling gap of an In0.28Ga0.72Sb/AlSb heterojunction with a VBO of 0.47 eV and CBO of 0.65 eV is also sufficient to prevent both electron and hole leakage currents in CMOS devices. (C) 2017 The Japan Society of Applied Physics
Impact of interfacial misfit dislocation growth mode on highly lattice-mismatched InxGa1-xSb epilayer grown on GaAs substrate by metalorganic chemical vapor deposition
(2016-09-05)
Huynh, Sa Hoang
;
Minh Thien Huu Ha
;
Huy Binh Do
;
Quang Ho Luc
;
Yu, Hung Wei
Highly lattice-mismatch (over 8%) ternary InxGa1-xSb alloy directly grown on GaAs substrates was demonstrated by metalorganic chemical vapor deposition (MOCVD). The influence of growth parameters, such as growth temperature, indium vapor composition, and V/III ratio, on the film properties was investigated, and it was found that the growth temperature has the strongest effect on the surface morphology and the crystal quality of the InxGa1-xSb epilayer. An optimized growth temperature of similar to 590 degrees C and a V/III ratio of 2.5 were used for the growth of the InxGa1-xSb epilayer on GaAs that displays a lower surface roughness. High-resolution transmission electron microscopy micrographs exhibit that InxGa1-xSb epilayer growth on GaAs was governed by the interfacial misfit dislocation growth mode. Furthermore, the variation of the intermixing layer thickness at the InxGa1-xSb/GaAs heterointerface was observed. These results provide an information of growing highly lattice-mismatched epitaxial material systems by MOCVD growth process. Published by AIP Publishing.
In0.53Ga0.47As FinFET and GAA-FET With Remote-Plasma Treatment
(2018-03-01)
Luc, Quang Ho
;
Yang, Kun Sheng
;
Lin, Jia Wei
;
Chang, Chia Chi
;
Huy Binh Do
This letter presents a remote NH3/N-2 plasma treatment after gate oxide deposition for improving the electrical characteristics and the reliability of In0.53Ga0.47As FinFET. The plasma treatment enhanced drive current (I-DS), transconductance (G(m)), subthreshold swing (SS), flicker noise, and positive bias temperature lifetime, suggesting that this plasma treatment significantly improves the quality of the etched In0.53Ga0.47As channel interface. In0.53Ga0.47As FinFETs and gate-all-around FETs were fabricated with the proposed in situ remote-plasma treatment and characterized.
Investigation of Multilayer TiNi Alloys as the Gate Metal for nMOS In0.53Ga0.47As
(2016-12)
Do, Huy Binh
;
Luc, Quang Ho
;
Ha, Minh Thien Huu
;
Huynh, Sa Hoang
;
Hu, Chenming Calvin
To achieve low power consumption for CMOS devices, the gate metals must have effective work function (EWF) aligned with the band edges of the channel material and have a small WF variation (WFV). The multilayer TiNi alloys have been successfully applied as the gate metals for HfO2/In0.53Ga0.47As MOS devices in this paper. The EWF of TiNi alloys was found to increase from 4.41 eV for as-deposited sample to 4.62 eV after the alloy was annealed due to the diffusion of Ni atoms into Ti layer. The multilayer TiNi alloy remained amorphous phase with small WFV until annealed at 600 degrees C. The TiNi alloy is thermally more stable as compared with either Ti or Ni metal, because the TiOxNi interfacial layer prevents the diffusion of Ni atoms into HfO2 film and the further reaction of Ti with HfO2. The results can be applied for InGaAs nMOS fabrication.
Study of the interface stability of the metal (Mo, Ni, Pd)/HfO2/AlN/InGaAs MOS devices
(2017-08-01)
Do, Huy Binh
;
Luc, Quang Ho
;
Ha, Minh Thien Huu
;
Huynh, Sa Hoang
;
Nguyen, Tuan Anh
The degeneration of the metal/HfO2\ interfaces for Mo, Ni, and Pd gate metals was studied in this paper. An unstable PdOx interfacial layer formed at the Pd/HfO2 interface, inducing the oxygen segregation for the Pd/HfO2/InGaAs metal oxide capacitor (MOSCAP). The low dissociation energy for the Pd-O bond was the reason for oxygen segregation. The PdOx layer contains O2- and OH- ions which are mobile during thermal annealing and electrical stress test. The phenomenon was not observed for the (Mo,Ni)/HfO2/InGaAs MOSCAPs. The results provide the guidance for choosing the proper metal electrode for the InGaAs based MOSFET. (C) 2017 Author(s).
The effect of a and Ga intermediate layer on the interfacial layer properties of epitaxial GaSb on GaSb grown by metalorganic chemical vapor deposition
(2019-01-01)
Ha, Minh Thien Huu
;
Huynh, Sa Hoang
;
Do, Huy Binh
;
Lee, Ching Ting
;
Luc, Quang Ho
A method for the growth of high quality GaSb epilayer on GaAs (001) substrate is demonstrated in this study. It is found that a superior GaSb/GaAs interface can be obtained by depositing a thin Sb-precursor layer on the GaAs substrate containing a GaAs buffer layer. It is suggested that the growth occurs via the interface misfit (IMF) growth mode. Without this treatment, GaSb epilayer may grow according to the Stranski-Krastanov mechanism or via a blend of the Stranski-Krastanov and IMF mechanisms, leading to an inferior GaSb/GaAs interface. This could be due to the intermixing of anions, leading to the turbulent composition and misfit dislocation distribution at the heterointerface. It appears that with the addition of a Sb layer, IMF arrays can be formed at GaSb/GaAs interface resulting in superior GaSb layer without the need for changing the growth parameters.