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3. Orthodox etching of HVPE-grown GaN

Author

Weyher, J.L., Lazar, S., Macht, L., Liliental-Weber, Z., Molnar, R.J., Muller, S., Nowak, G., and Grzegory, I.

Subjects
Materials science
Published
2006

8. Measurement of second order susceptibilities of GaN and AlGaN

Author

Sanford, N.A., Mishra, U.K., Davydov, A.V., DenBaars, S.P., Tsvetkov, D.V., Park, S.S., Dmitriev, A.V., Han, J.Y., Keller, S., and Molnar, R.J.

Subjects
Dielectric films -- Research, Thin films -- Research, Epitaxy -- Research, Gallium nitrate -- Thermal properties, Physics
Abstract

Rotational Maker fringes were used to measure the non-linear susceptibilities chi[(super 2)(sub 31)] and chi[(super 2)(sub 33)] for a series of metalorganic chemical vapor deposition (MOCVD) and hydride vapor-phase epitaxy (HVPE) AlxGa1-xN thin-film samples grown on sapphire substrates. The results are consistent with theoretical studies of nonlinear susceptibilities for GaN and AlGaN.

Published
2005

10. Low-frequency noise in n-GaN with high electron mobility

Author

Levinshtein, M.E., Rumyantsev, S.L., Look, D.C., Molnar, R.J., Khan, M. Asif, Simin, G., Adivarahan, V., and Shur, M.S.

Subjects
Electromagnetic noise -- Measurement, Gallium compounds -- Research, Semiconductors -- Research, Physics
Abstract

Low-frequency noise in n-type gallium nitride (GaN) deposited on sapphire with electron mobility of 790 square cm/V s at 300 K has been measured. Results indicate that the level of flicker noise in GaN is highly dependent on the structure of the material. The effects of band-to-band illumination on the low-frequency noise indicate that 1/f noise in GaN may result from the occupancy fluctuations of the tail states near the band edges.

Published
1999

11. Effect of growth temperature on point defect density of unintentionally doped GaN grown by metalorganic chemical vapor deposition and hydride vapor phase epitaxy

Author

Joshkin, V.A., Parker, C.A., Bedair, S.M., Muth, J.F., Shmagin, I.K., Kolbas, R.M., Piner, E.L., and Molnar, R.J.

Subjects
Gallium compounds -- Research, Epitaxy -- Research, Chemical vapor deposition -- Usage, Thin films -- Research, Physics
Abstract

Research was conducted to examine the effect of growth temperature on point defect density of unintentionally doped GaN grown by atmospheric pressure metalorganic chemical vapor deposition and hydride vapor phase epitaxy. It was observed that oxygen created a shallow donor in GaN with an activation energy of approximately 23.5+/-meV. Based on Hall investigations, it was concluded that a third donor in GaN has an activation energy of 110+/-10meV.

Published
1999

12. Growth of gallium nitride by electron-cyclotron resonance plasma-assisted molecular-beam epitaxy: the role of charged species

Author

Molnar, R.J. and Moustakas, T.D.

Subjects
Gallium compounds -- Growth, Particles (Nuclear physics) -- Research, Thin films -- Research, Physics
Abstract

Secondary-ion-mass spectroscopy of gallium nitride (GaN) thin films grown by electron-cyclotron resonance (ECR) plasma-assisted molecular-beam epitaxy to determine the function of nonionic and ionic excited nitrogen species during GaN film growth reveals that the microwave power of ECR discharge influences growth kinetics and that increase in impurities and native defects disrupts luminescence and electrical properties. Films grown under reduced ionic/excited neutral ratio conditions display an enhancement in their electrical and luminescence properties, showing that a decrease in native defects enhances the film properties.

Published
1994

13. List of contributors

Author

Accomo, R., primary, Achtziger, N., additional, Adams, S.J.A., additional, Akasaki, I., additional, Albert, J.P., additional, Amano, H., additional, André, R., additional, Antonelli, A., additional, Asif Khan, M., additional, Aulombard, R.L., additional, Austin, R.F., additional, Balestrino, G., additional, Baltramiejūnas, R., additional, Bechstedt, F., additional, Bécourt, N., additional, Bergman, L., additional, Bernholc, J., additional, Bertho, D., additional, Bertoni, CM., additional, Billat, S., additional, Boćkowski, M., additional, Bodin, C., additional, Bodin-Deshayes, C., additional, Boiko, E.B., additional, Boring, P., additional, Bouhelal, A., additional, Bratina, G., additional, Brennan, K.F., additional, Briddon, P.R., additional, Briot, O., additional, Broser, I., additional, Bsiesy, A., additional, Bucher, E., additional, Burchard, A., additional, Cantwell, G., additional, Carter, C.H., additional, Castro, T., additional, Cavenett, B.C., additional, Chadi, D.J., additional, Chen, K.M., additional, Chen, X., additional, Cheng, H., additional, Choyke, W.J., additional, Christensen, N.E., additional, Cibert, J., additional, Cingolani, R., additional, Cloitre, T., additional, Cohen, P.I., additional, Collins, A.T., additional, Cotal, H.L., additional, Cricenti, A., additional, Dabbicco, M., additional, Dang, L.S., additional, Davis, R.F., additional, Deicher, M., additional, DePuydt, J.M., additional, Dischler, B., additional, Dmitriev, V.A., additional, Donegan, J.F., additional, Doran, J.P., additional, Dubowski, J.J., additional, Eckey, L., additional, Edmond, J.A., additional, Efros, A.L., additional, Egan, R.J., additional, Engelbrecht, F., additional, Evstropov, W., additional, Fanciulli, M., additional, Feldman, R.D., additional, Felici, A.C., additional, Ferrara, M., additional, Ferrari, L., additional, Ferry, D.K., additional, Feuillet, G., additional, Fiedler, M., additional, Finocchi, F., additional, Fischer, R., additional, Fishman, G., additional, Franciosi, A., additional, Fricke, Ch., additional, Frolov, S.I., additional, Fuchs, D., additional, Galli, G., additional, Gaponenko, S.V., additional, Gaspard, F., additional, Gavrilenko, V.I., additional, Gavryushin, V., additional, Gebhardt, W., additional, Germanenko, I.N., additional, Geurts, J., additional, Geyzers, K.P., additional, Gil, B., additional, Gladfelter, W., additional, Gleitsman, G., additional, Göbel, E.O., additional, Godet, C., additional, Goede, O., additional, Gorczyca, I., additional, Gribkovskii, V.P., additional, Grzegory, I., additional, Gumlich, H.-E., additional, Gunshor, R.L., additional, Gurskii, A.L., additional, Gutowski, J., additional, Gygi, F., additional, Haase, M.A., additional, Haberstroh, C, additional, Harsch, W.C., additional, Hauksson, I., additional, Hayashi, S., additional, Hegarty, J., additional, Heimbrodt, W., additional, Heime, K., additional, Heine, V., additional, Heitz, R., additional, Helbig, R., additional, Henderson, B., additional, Henneberger, F., additional, Hérino, R., additional, Hermans, J., additional, Heuken, M., additional, Hoffmann, A., additional, Hoffmann, H., additional, Hoffmann, N., additional, Hofsäss, H., additional, Humphreys, T.P., additional, Hunt, R.W., additional, Iarlori, S., additional, Iida, S., additional, Ikoma, K., additional, Itie, J.P., additional, Jacobs, K., additional, Jahn, S.G., additional, Jancu, J.M., additional, Jaussaud, C., additional, Jentzsch, T., additional, Johnson, R.L., additional, Jones, R., additional, Jouanin, C., additional, Jouneau, P.H., additional, Jun, J., additional, Jungnickel, V., additional, Juodžbalis, D., additional, Kajihara, S.A., additional, Kanicki, J., additional, Karmann, S., additional, Katayama-Yoshida, H., additional, Kawakami, Y., additional, Kazlauskas, A., additional, Kean, A., additional, Khan, M.R.H., additional, King-Smith, R.D., additional, Kinto, H., additional, Kißmann, U., additional, Klimakow, A., additional, Klyui, N.I., additional, Koide, N., additional, Koidl, P., additional, Kong, H.-S., additional, Kong, H.S., additional, König, Th., additional, Kono, J., additional, Kononenko, V.K., additional, Kotaki, M., additional, Kreß, C., additional, Krings, T., additional, Krukowski, St., additional, Kubertavicius, V., additional, Kudlek, G.H., additional, Kuhn, W., additional, Kunc, K., additional, Kuroda, Y., additional, Kuznia, J.N., additional, Kwak, K.W., additional, Labrunie, G., additional, Laks, D.B., additional, Lambrecht, W.R.L., additional, Lankes, S., additional, Lebed, V. Yu., additional, Lei, T., additional, Leibenzeder, S., additional, Lepore, M., additional, Licht, T., additional, Ligeon, M., additional, Linkov, I. Yu., additional, Litwin-Staszewska, E., additional, Logothetidis, S., additional, Luce, G., additional, Lutsenko, E.V., additional, Lux-Steiner, M. Ch., additional, Madéore, F., additional, Magerle, R., additional, Mahnke, H.-E., additional, Maier, K., additional, Malinovskii, I.E., additional, Manabe, K., additional, Marinelli, M., additional, Markey, B.G., additional, Markwitz, A., additional, Marshall, T., additional, Mathieu, H., additional, Matsunami, H., additional, McCaldin, J.O., additional, McGill, T.C., additional, McKeever, S.W.S., additional, Meier, J., additional, Mihalcescu, I., additional, Milani, E., additional, Mitcovets, A.I., additional, Mitsuyu, T., additional, Miura, N., additional, Molnar, R.J., additional, Molva, E., additional, Morohashi, M., additional, Morozenko, Ya.V., additional, Moustakas, T.D., additional, Mujica, A., additional, Mula, G., additional, Muller, F., additional, Müller-Sebert, W., additional, Muñoz, A., additional, Mura, A., additional, Naumov, A., additional, Needs, R.J., additional, Nemanich, R.J., additional, Nicolini, R., additional, Nurmikko, A.V, additional, O'Donnell, K.P., additional, Oguchi, T., additional, Ohkawa, K., additional, Okamoto, S., additional, Okazaki, N., additional, Okumura, H., additional, Osman, M.A., additional, Palmour, J.W., additional, Paloura, E.C., additional, Palummo, M., additional, Paoletti, A., additional, Papon, A.M., additional, Paroli, P., additional, Parrinello, M., additional, Pensl, G., additional, Pereira, E., additional, Perlin, P., additional, Petalas, J., additional, Pfeiffer, W., additional, Phillips, M.C., additional, Pikus, F.G, additional, Pinter, I., additional, Pirzer, M., additional, Pohl, U., additional, Pohl, U.W., additional, Polatoglou, H.M., additional, Polian, A., additional, Polini, R., additional, Ponga, B.E., additional, Ponthenier, J.L., additional, Porowski, S., additional, Prins, J.F., additional, Prior, K.A., additional, Puls, J., additional, Qiu, J., additional, Qteish, A., additional, Raciukaitis, G., additional, Reining, L., additional, Reisinger, T., additional, Restle, M., additional, Righini, M., additional, Rodríguez-Hernández, P., additional, Rolfe, S.J., additional, Romestain, R., additional, Ryzhikov, VD., additional, Sailer, B., additional, Sander, D., additional, Santos, L., additional, Sasaki, T., additional, Sawada, M., additional, Scamarcio, G., additional, Scarselli, M.A., additional, Schadt, M., additional, Schneider, A., additional, Schneider, J., additional, Schöner, A., additional, Schülzgen, A., additional, Selci, S., additional, Shinohara, M., additional, Simpson, J., additional, Sorba, L., additional, Spellmeyer, B., additional, Stanley, R.P., additional, Stanzl, H., additional, Stein, R.A., additional, Stewart, H., additional, Suemune, I., additional, Sulzer, G., additional, Suski, T., additional, Suttrop, W., additional, Swenberg, J.F., additional, Taghizadeh, M.R., additional, Takeyama, S., additional, Tansley, T.L., additional, Tebano, A., additional, Thurian, P., additional, Tosatti, E., additional, Trager-Cowan, C., additional, Troullier, N., additional, Tschentscher, I., additional, Tsuboi, N., additional, Tsujimura, A., additional, Tsukioka, K., additional, Tupenevich, P.A., additional, Turner, K.F., additional, Uchiki, H., additional, Uhrmacher, M., additional, Ullrich, B., additional, Uttamchandani, D., additional, Van de Walle, C.G., additional, van der Weide, J., additional, Van Hove, J.M., additional, Vanderbilt, D., additional, Vanzetti, L., additional, Vasileska, D., additional, Vial, J.C., additional, Wagner, H.P., additional, Wahl, U., additional, Waldmann, H., additional, Walker, CT., additional, Wang, E.G., additional, Wang, M.W., additional, Wang, S.Y., additional, Wang, Y., additional, Weinhold, V., additional, Wiehert, T., additional, Wild, C., additional, Witthuhn, W., additional, Wolf, H., additional, Wolf, K., additional, Wörz, M., additional, Yablonskii, G.P., additional, Yagi, M., additional, Yamaga, S., additional, Yamanaka, M., additional, Yang, F., additional, Yoshii, S., additional, Yoshikawa, A., additional, Yu, X., additional, Zeitz, W., additional, and Zimin, L.G., additional

Published
1993
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17. Evidence for shallow acceptors in GaN

Author

Reynolds, D.C., Look, D.C., Jogai, B., and Molnar, R.J.

Subjects
Exciton theory -- Research, Photoluminescence -- Research, Physics -- Research, Semiconductors -- Research, Physics
Abstract

Research describing the photoluminescence characteristics of gallium nitride crystals is presented. In particular two emission lines are reinterpreted as evidence of acceptor bound excitons.

Published
2001

21. Unusual luminescence lines in GaN.

Author

Reshchikov, M. A., Huang, D., Yun, F., Visconti, P., He, L., Morkoç, H., Jasinski, J., Liliental-Weber, Z., Molnar, R.J., Park, S.S., and Lee, K.Y.

Subjects
GALLIUM nitride, LUMINESCENCE, PHOTOLUMINESCENCE, PHOTONS
Abstract

A series of sharp intense peaks was observed in the low-temperature photoluminescence spectrum of unintentionally doped GaN in the photon energy range between 3.0 and 3.46 eV. We attributed the majority of these peaks to excitons bound to unidentified structural and surface defects. Most of the structural- and surface-related peaks (at 3.21, 3.32, 3.34, 3.35, 3.38, and 3.42 eV) were observed in Ga polar films. In N polar GaN, we often observed the 3.45 eV peak attributed to excitons bound to the inversion domain interfaces. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2003
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22. High mobility AlGaN/GaN heterostructures grown by plasma-assisted molecular beam epitaxy on semi-insulating GaN templates prepared by hydride vapor phase epitaxy

Author

Manfra, M.J. ; Weimann, N.G. ; J.W.P. Hsu ; Pfeiffer, L.N., West, K.W. ; Syed, S. ; Stormer, H.L., Pan, W. ; D.V. Lang ; S.N.G. Chu, Kowach, G. ; Sergent, A.M. ; Caissie, J., and Molvar, K.M. ; Mahoney, L.J. ; Molnar, R.J

Subjects
Gallium arsenide -- Properties, Aluminum -- Properties, Physics
Abstract

An extensive study of the growth and transport properties of a two-dimensional electron gas (2DEG) confined at the interface of an AlGaN/GaN heterostructure grown by molecular beam epitaxy (MBE) on highly resistive GaN templates prepared by hydride vapor phase epitaxy (HVPE). The result demonstrates that thick semiinsulating GaN templates grown by HVPE are a viable substrate for the growth of high electron mobility transistors (HEMTs).

Published
2002

23. Scanning Kelvin probe microscopy of surface electronic structure in GaN grown by hydride vapor phase epitaxy

Author

Simpkins, B.S., Schaadt, D.M., Yu, E.T., and Molnar, R.J.

Subjects
Physics
Abstract

The imaging and analysis, using scanning Kelvin probe microscopy (SKPM), of the nature and spatial distribution of surface potential variations present in GaN films grown by hydride vapor phase epitaxy (HVPE), is presented. The SKPM measurements confirm that the surface potential variations typically ~0.1-0.2 V in magnitude, and that these variations are associated to a large degree with threading dislocations present at the GaN surface.

Published
2002

24. Depth-dependent investigation of defects and impurity doping in GaN/sapphire using scanning electron microscopy and cathodoluminescence spectroscopy

Author

Sun, X.L., Goss, S.H., Brillson, L.J., Look, D.C., and Molnar, R.J.

Subjects
Electron microscopy -- Usage, Cathodoluminescence -- Usage, Gallium nitrate -- Research, Gallium nitrate -- Electric properties, Physics
Abstract

Cathodoluminescence (CL) imaging and temperature-dependent cathodoluminescence spectroscopy (CLS) are used to probe the spatial distribution and energies of electronic defects near GaN/Al(sub 2)O(sub 3) interfaces grown by hydride vapor phase epitaxy (HVPE). CL imaging and temperature dependent CLS show systematic variations in defect emissions with a wide range of HVPE GaN/sapphire electronic properties.

Published
2002

25. Deep hole traps in n-GaN films grown by hydride vapor phase epitaxy

Author

Polyakov, A.Y., Smirnov, N.B., Govorkov, A.V., Fang, Z.-Q., Look, D.C., Osinsky, A.V., and Molnar, R.J.

Subjects
Epitaxy -- Research, Gallium nitrate -- Research, Gallium nitrate -- Chemical properties, Dielectric films -- Research, Thin films -- Research, Physics
Abstract

Deep hole traps located below the Fermi level and having a high density can be presented in hydride vapor phase epitaxy (HVPE) n-GaN samples as evidenced by low temperature C - V and C - T measurements before and after illumination. An increase of layer thickness in the HVPE process seems to significantly improve the situation with regard to the density of deep hole traps.

Published
2002

26. Ion-beam processing effects on the thermal conductivity of n-GaN/sapphire (0001)

Author

Florescu, D.I., Pollak, Fred H., Lanford, William B., Khan, Farid, Molnar, R.J., and Adesida, I.

Subjects
Sapphires -- Thermal properties, Gallium nitrate -- Thermal properties, Physics
Abstract

The thermal conductivity (k) behavior before and after inductively coupled plasma processing on two series of hydride vapor phase epitaxy (HVPE) n-GaN/sapphire (0001) samples is discussed. The influence of damage and removal on k is likely to be more important for plasma-processes devices and their thermal modeling.

Published
2002

49. Electron scattering in AlGaN/GaN structures.

Author

Syed, S., Manfra, M.J., Wang, Y.J., Molnar, R.J., and Stormer, H.L.

Subjects
HETEROJUNCTIONS, ELECTRON scattering, GALLIUM nitride, SCATTERING (Physics), QUANTUM theory, CYCLOTRON resonance
Abstract

We present data on mobility lifetime τ[sub t], quantum lifetime τ[sub q], and cyclotron resonance lifetime τ[sub CR], of a sequence of high-mobility two-dimensional electron gases in the AlGaN/GaN system, covering a density range of 1 to 4.5×10[sup 12] cm[sup -2]. We observe a large discrepancy between τ[sub q] and τ[sub CR](τ[sub q]∼τ[sub CR]/6), and explain it as the result of density fluctuations of only a few percent. Therefore, only τ[sub CR]—and not τ[sub q]—is a reliable measure of the time between electron-scattering events in these specimens. The ratio τ[sub t]/τ[sub CR] increases with increasing density in this series of samples, but scattering over this density range remains predominantly in the large-angle scattering regime. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2004
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50. Rapid evaluation of dislocation densities in n-type GaN films using photoenhanced wet etching.

Author

Youtsey, C., Romano, L.T., Molnar, R.J., and Adesida, I.

Subjects
THIN films, GALLIUM nitride
Abstract

Describes a technique based on photoelectrochemical wet etching that enables efficient and accurate evaluation of dislocation densities in n-type GaN thin films. Use of dilute aqueous KOH solutions and Hg arc lamp illumination by the etching process to produce GaN whiskers.

Published
1999
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