Ingaas/inp Quantum Wells With Thickness Modulation

We investigated the optical properties of lattice-matched InGaAs/InP quantum wells grown by metalorganic molecular beam epitaxy on top of patterned InP buffer layers with elongated features along the [01̄1] direction. The resulting quantum wells present a periodic thickness variation following the elongated features. Low temperature luminescence measurements exhibit double emission bands, attributed to distinct regions of the well. Temperature evolution of the photoluminescence spectra gives qualitative information about the effect of exciton localization.65785785

GaN Metal Oxide Semiconductor Field Effect Transistors

A GaN based depletion mode metal oxide semiconductor field effect transistor (MOSFET) was demonstrated using Ga{sub 2}O{sub 3}(Gd{sub 2}O{sub 3}) as the gate dielectric. The MOS gate reverse breakdown voltage was > 35V which was significantly improved from 17V of Pt Schottky gate on the same material. A maximum extrinsic transconductance of 15 mS/mm was obtained at V{sub ds} = 30 V and device performance was limited by the contact resistance. A unity current gain cut-off frequency, f{sub {tau}}, and maximum frequency of oscillation, f{sub max} of 3.1 and 10.3 GHz, respectively, were measured at V{sub ds} = 25 V and V{sub gs} = {minus}20 V

Temperature Dependence Of Morphology Of Inp Films Grown By Metalorganic Molecular Beam Epitaxy

Two regimes of growth are observed for epitaxial films of InP prepared by metalorganic molecular beam epitaxy. Below a minimum growth temperature, Tg min, kinetic roughening is observed. At temperatures higher than Tg min, smooth morphologies are obtained. From the dependence of Tg min, on the substrate misorientation, we estimate a value of nearly 0.4-0.5 eV for the Schwoebel barrier. At growth temperatures higher than Tg min we observe two types of defects: large oval defects related only to the initial conditions of the substrate surface and small defects with the density strongly dependent on the growth condition. Increasing temperature above Tg min, or decreasing V/III ratio, results in increased density of these defects. In addition, their density increases with an activation energy that depends on the substrate misorientation. The origin of the oval defects in attributed to non-stoichiometric, P-defficient, clusters on the growing surface, formed either by enhanced cracking of metalorganics on the substrate due to the presence of contamination or by a low V/III ratio used for growth.31712312

Kinetic Roughness In Epitaxy (experimental)

Different regimes of growth morphology are observed for InP films prepared by metal-organic molecular beam epitaxy. Below a well-defined minimum growth temperature Tg min kinetic roughening is observed. From the temperature dependence of roughening near Tg min for substrates with different misorientations we estimate a value of 0.4-0.5 eV for the Schwoebel-Erlich step crossing barrier. At growth temperatures higher than Tg min we observe the formation of localized surface defects associated with vacancies. The density of defects is strongly dependent on the thermodynamic and kinetic growth parameters. © 1995.302-3137142Neave, Dobson, Joyce, Zhang, (1985) Appl. Phys. Lett., 47, p. 100Shitara, Vvedensky, Wilby, Zhang, Neave, Joyce, (1992) Phys. Rev. B, 46, p. 6825Schwoebel, Shipsey, (1966) J. Appl. Phys., 37, p. 3682Erlich, Hudda, Atomic View of Surface Self-Diffusion: Tungsten on Tungsten (1966) The Journal of Chemical Physics, 44, p. 1039Fink, Erlich, (1984) Surf. Sci., 143, p. 125Cotta, Hamm, Staley, Chu, Harriott, Panish, Temkin, (1993) Phys. Rev. Lett., 70, p. 4106Johnson, Orme, Hunt, Graff, Sudijono, Sander, Orr, (1994) Phys. Rev. Lett., 72, p. 116Fukui, Saito, Natural Superstep Formed on GaAs Vicinal Surface by Metalorganic Chemical Vapor Deposition (1990) Japanese Journal of Applied Physics, 29, p. L483Kasu, Kobayashi, (1993) Appl. Phys. Lett., 62, p. 1262Ohta, Kojima, Nakagawa, (1989) J. Cryst. Growth, 95, p. 71T. Ohno, K. Shiraishi and T. Ito, 1993 Materials Research Society Fall Meet., Symp. MPashley, Haberern, Gaines, (1991) Appl. Phys. Lett., 58, p. 406Panish, Temkin, (1993) Gas-Source Molecular Beam Epitaxy, pp. 23-24. , Springer, BerlinChand, Chu, (1990) J. Cryst. Growth, 104, p. 485Khulbe, Dobal, Bist, Mehta, Muralidharan, Jain, (1993) Appl. Phys. Lett., 63, p. 488Lambert, Pèralés, Vergnaud, Stark, (1990) J. Cryst. Growth, 105, p. 97Morishita, Maruno, Gotoda, Nomura, Ogata, (1989) J. Cryst. Growth, 95, p. 176das Sarma, Lanczychi, Ghaisas, Kim, (1994) Phys. Rev. B, 49, p. 1069