MBE growth of GaN nanowires on Si(111) substrates for gas sensor applications 

Kamil Klosek 1Marta Sobanska 1Zbigniew R. Zytkiewicz 1Anna Reszka 1Renata Kruszka 2Krystyna Golaszewska 2Maciej Setkiewicz 3Tadeusz Pustelny 3

1. Polish Academy of Sciences, Institute of Physics, Lotnikow 32/46, Warsaw 02-668, Poland
2. Institute of Electron Technology (ITE), al. Lotników 32/46, Warszawa 02-668, Poland
3. Silesian University of Technology, Gliwice 44-100, Poland


Nanowires (NWs) made of GaN and related group III-N alloys, having a huge potential for new devices, attract much attention recently. The GaN-based materials are very thermally and chemically stable. This makes them very suitable for operation in chemically harsh environments. Therefore, wide band-gap group III nitride compound semiconductors are alternative options to supplement silicon, in particular in chemical sensor applications [1].
The aim of this paper is to report on our developments in plasma-assisted MBE growth of GaN NWs on Si(111) substrates and on their application in gas sensors. Two types of growth procedures were used to prepare  GaN NWs structures. The first one, standard catalyst-free MBE growth at N-rich conditions, resulted in a dense ensemble of GaN NWs being ~400 – 500 nm long with diameter of 20 – 30 nm (see Fig. 1). They were homogenously distributed and well oriented with the c-axis being perpendicular to the substrate. Density of nanowires was quite large. Therefore, even a small tilt of some of them, estimated from XRD to be below ±2o, led to a partial coalescence in upper parts of NWs. In the second procedure, after growth of ~1 µm long NWs the conditions were changed to Ga-rich by increasing the Ga flux and reducing growth temperature. As the result the NWs were overgrown with a planar GaN layer (see Fig. 2).

Two types of GaN NWs based gas sensors were fabricated. For the planar device samples with ensemble of GaN NWs grown on semiinsulating Si(111) substrates were used. Then, Ti/Al/Au electrical contacts having diameters of 400 µm were defined on the surface by standard photolithography and lift-off processes and annealed to form low resistance source and drain electrodes. Since NWs were closely packed thin bridges connecting them were created in the active area of the device between the electrodes. In vertical sensor devices electrical resistivity along the NWs, not across the NWs as in a planar geometry, is measured. In such a case, we used conductive Si substrate and overgrowth of NWs with a compact GaN layer. Then, a mesa-type sensors were made by dry etching and metal deposition techniques.
Finally, both types of structures were electrically tested in NO2, NH3 and hydrogen atmospheres at temperatures up to 80 oC to check and compare their gas sensing properties.

This work was partly supported by the European Regional Development Fund through grant Innovative Economy (POIG.01.01.02-00-008/08 NanoBiom). Some of us (MS and TP) are grateful for support from the POIG.01.03.01-00-159/08 Project.

 [1]  S.J. Pearton, et al., Prog. Mat. Sci. 55, 1-59 (2010);

Legal notice
  • Legal notice:

    Copyright (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: http://science24.com/paper/29018 must be provided.


Related papers
  1. Growth and properties of inclined GaN nanowires on Si(001) substrates by PAMBE
  2. Optimization of nitrogen plasma source parameters for growth of GaN by MBE
  3. Mechanism of in-plane orientation of GaN self-induced nanowires grown on Si(111) substrates 
  4. Bulk GaAs growth by Contactless Liquid Phase Electroepitaxy
  5. Impact of substrate microstructure on self-induced nucleation and properties of GaN nanowires grown by plasma-assisted MBE
  6. Modelling of X-Ray diffraction curves for GaN nanowires on Si(111)
  7. Measurements of strain in AlGaN/GaN HEMT structures grown by plasma assisted molecular beam epitaxy
  8. Optical Characterisation of Bulk ZnO Crystals Grown by CVT
  9. Physical properties of unique ZnO single crystals from Oława Foundry
  10. Electronic and optical properties – As and As+Sb doped ZnO grown by PA-MBE
  11. Grown ZnMgO/ZnO/ZnMgO heterostructures on p-type Si(111) by MBE method
  12. Dual-acceptor doped p-ZnO:(As+Sb)/n-GaN heterojunctions grown by PA-MBE as a highly selective UV detector
  13. Structural, morphological and optical properties of ZnAl2O4 nanoparticles co-doped with Er3+and Yb3+ prepared by combustion aerosol synthesis.
  14. Influence of substrate on crystallographic quality of AlGaN/GaN HEMT structures grown by MBE
  15. Resonant photoemission study of Sm atoms on ZnO surface
  16. X-ray photoemission from CdTe/PbTe/CdTe nanostructure in normal and grazing-incidence modes
  17. Investigation of strain and lattice parameters distribution in epitaxial laterally overgrown InGaN/GaN structures 
  18. ZnO and core/shell ZnO/ZnS nanofibers: Characterization and applications
  19. Innowacyjne technologie wielofunkcyjnych materiałów i struktur dla nanoelektroniki, fotoniki, spintroniki i technik sensorowych (InTechFun).
  20. Liquid phase growth and characterization of laterally overgrown GaSb epitaxial layers
  21. Photothermal investigations of SiC thermal properties
  22. Characterization of Ir and IrO2 Schottky contacts on n-type 4H-SiC under high temperature stress
  23. Distribution of strain in laterally overgrown GaAs layers determined by x-ray diffraction
  24. Determination of stress in composite engineered substrates for GaN-based RF power devices
  25. Optimisation of electrochemical sulphur treatment of GaSb and related semiconductors: application to surface passivation of GaSb/In(Al)GaAsSb TPV cells
  26. Comparison of various GaSb-based device structures for application in thermophotovoltaic cells
  27. TaSiN, TiSiN and TiWN diffusion barriers for metallization systems to GaN
  28. Transparent Conducting Oxides as Ohmic Contacts for GaSb-based Thermophotovoltaic Cells
  30. Thermally stable Ru-Si-O gate electrode for AlGaN/GaN HEMT
  31. p-type conducting ZnO: fabrication and characterisation
  32. Diffusion barrier properties of reactively sputtered W-Ti-N thin films
  33. Structure modifications in materials irradiated by ultra-short pulses of VUV free electron laser
  34. Study of Long-Term Stability of Ohmic Contacts to GaN
  35. Novel substrates for heteroepitaxy by lateral overgrowth technology

Presentation: Poster at 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17, Topical Session 3, by Kamil Klosek
See On-line Journal of 17th International Conference on Crystal Growth and Epitaxy - ICCGE-17

Submitted: 2013-03-28 15:31
Revised:   2013-07-31 15:12
Web science24.com
© 1998-2022 pielaszek research, all rights reserved Powered by the Conference Engine