| 51. |
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| 52. |
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| 53. |
- Zhao Ternehäll, Huan, 1982, et al.
(författare)
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Comparison of optical and structural quality of GaIn(N) As analog and digital quantum wells grown by molecular beam epitaxy
- 2008
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Ingår i: Semiconductor Science and Technology. - : IOP Publishing. - 0268-1242 .- 1361-6641. ; 23:12, s. 125002-
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Tidskriftsartikel (refereegranskat)abstract
- A set of Ga0.625In0.375(N) As single quantum well (QW) samples with the identical total amounts of Ga and In and QW thicknesses was designed and grown by both the analog and the digital methods using molecular beam epitaxy. The N exposure time in the GaInNAs samples was kept the same. The inter-band gap recombination in the analog and the digital InGaAs QWs appears in a similar transition energy range as a result of In segregation. Temperature-dependent photoluminescence (PL) measurements were performed on the GaInNAs samples. An S-shaped dependence of the transition energy on temperature was observed in the digital GaInNAs QWs but not in the analog GaInNAs QW. Post-growth rapid thermal annealing had remarkably different effects on the PL intensity: an increase for the analog InGaAs QW and for the analog and digital GaInNAs QWs, but a decrease for the digital InGaAs QW with increasing annealing temperature. The GaIn(N) As samples grown by the digital method showed weaker PL intensities and smaller wavelength blue-shifts than the similar samples grown by the analog method. Possible strain relaxation mechanisms are discussed.
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| 54. |
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| 55. |
- Zhao Ternehäll, Huan, 1982, et al.
(författare)
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Effect of bismuth on structural and electrical properties of InAs films grown on GaAs substrates by MBE
- 2015
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248. ; 425, s. 89-93
-
Tidskriftsartikel (refereegranskat)abstract
- © 2015 Elsevier B.V. All rights reserved. InAs films were grown on GaAs substrates by molecular beam epitaxy (MBE) without or with different Bi fluxes. The effect of Bi on the structural and electrical properties of the InAs films was studied. Atomic Force Microscopy (AFM) measurement showed clear surface steps in all samples, indicating an over-flow growth mode. A more uniform distribution and narrower spacing of the surface steps were observed with increased Bi fluxes. Small area AFM scans showed reduced surface roughness with increased Bi fluxes. Whereas from large area scans, reduced surface roughness was only observed in samples grown under low Bi fluxes, and a deteriorated surface was obtained in the sample grown under the highest Bi flux. Bi was not compositionally incorporated to the InAs films confirmed by X-ray diffraction (XRD) and Second Ion Mass Spectroscopy (SIMS) measurements. The electron mobility of the InAs films, measured at room temperature, decreased monotonically with increased Bi fluxes. This is correlated to the Transmission Electron Microscopy (TEM) results in which increased threading dislocation (TD) densities were shown with increased Bi fluxes. Therefore, Bi-mediated growth deteriorates the electron mobility of the MBE-grown InAs films, whereas smoother surface can be obtained by applying low Bi fluxes. Possible mechanisms were proposed to explain these phenomena.
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| 56. |
- Zhao Ternehäll, Huan, 1982, et al.
(författare)
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Effect of buffer design on structural and electrical properties of InAs films grown on GaAs substrates
- 2014
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Ingår i: the 41st international symposium on compound semiconductors, Montepillier, France.
-
Konferensbidrag (refereegranskat)abstract
- Different buffer structures were grown by molecular beam epitaxy (MBE) to accommodate the large lattice mismatch of InAs with GaAs substrate. A novel graded digital superlattice (GDSL) buffer design was proposed and compared with the common one-step buffer and linear alloy graded (LAG) buffer designs. Effect of buffer structures on structural and electrical properties of the InAs films was investigated. High quality InAs films were obtained on GaAs substrates.
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| 57. |
- Zhao Ternehäll, Huan, 1982, et al.
(författare)
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Effect of Buffer Quality on the Performance of InAs/AlSb Heterostructure Backward Tunneling Diode
- 2014
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Ingår i: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - 2162-2027 .- 2162-2035.
-
Konferensbidrag (refereegranskat)abstract
- InAs/AlSb Heterostructure Backward Tunneling Diodes (HBTDs) were grown on semi-insulating GaAs (100) substrate using molecular beam epitaxy (MBE). The current-voltage characteristics of the InAs/AlSb HBTDs, both at room temperatures (RT) and cryogenic temperatures, have been studied as a function of the InAs buffer thickness. It has been found that a thicker InAs buffer doesn’t improve the surface roughness but decreases the threading dislocation (TD) density, thus a higher curvature coefficient in the current-voltage characteristics near zero-bias is obtained.
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| 58. |
- Zhou, Hua, et al.
(författare)
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Design for Embedded Chinese Display Smart Card
- 2006
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Ingår i: 2006 Conference on High Density Microsystem Design and Packaging and Component Failure Analysis, HDP'06; Shanghai; China; 27 June 2006 through 28 June 2006. - 9781424404889 ; , s. 152-156
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Konferensbidrag (refereegranskat)abstract
- The storage and display of Chinese character data and the battery life are two bottle-necks of a Chinese display smart card which is one kind of super smart cards. This paper presented a new idea to realize the Chinese display which was a practice of embedded font solution. A dieform regular MCU, a smart card MCU and a graphical LCD controller(LCD driver) provided the main functions of the system to show Chinese characters on a graphical LCD panel, to receive operations from users and to run monitor program or, moreover, COS (Card Operating System). 2-Wire serial interface (TWI) was selected to be the communication protocol between the main MCU and the LCD controller in order to reduce the connection numbers and to enhance reliability. To minimize power consumption is one main design target for extending battery life. Besides selecting components with low power consumption, a power control scheme was designed to meet this requirement. A functional demonstrator was assembled in order to check the system desigh and to do the debug work.
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| 59. |
- Zou, Gang, 1970, et al.
(författare)
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High Frequency Flip Chip Interconnection on Liquid Crystal Polymer Substrate Using Anisotropic Conductive Adhesive
- 2004
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Ingår i: 2004 4th IEEE International Conference on Polymers and Adhesives in Microelectronics and Photonics; Portland, OR; United States; 12 September 2004 through 15 September 2004. - 0780387449 ; September:13-15, s. 137-140
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Konferensbidrag (refereegranskat)abstract
- An ACA flip-chip assembly of an MMIC on liquid crystal polymer (LCP) substrate is presented in this paper. The high frequency performance has been simulated using a lumped element model. The finite element method (FEM) computation of the thermal mechanical characterization of the ACA flip chip assembly in a cooling process was performed. The simulation results show that LCP has good high frequency performance. The LCP substrate has better thermal mechanical performance than a Teflon substrate.
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