Preparation of the ZnO substrate surface

Paweł Skupiński 1Krzysztof Grasza 1,2Andrzej Mycielski 1Elżbieta Łusakowska 1Halina Sakowska 2

1. Polish Academy of Sciences, Institute of Physics, al. Lotników 32/46, Warszawa 02-668, Poland
2. Institute of Electronic Materials Technology (ITME), Wólczyńska 133, Warszawa 01-919, Poland


ZnO is a material with a great potential for the applications in UV light emitters, spin functional devices, gas sensors, transparent electronics and surface acoustic wave devices. Large bulk crystals are usually grown by the hydrothermal method. In our Institute we use a less expensive chemical vapor transport (CVT) method to grow ZnO crystals.

Very important factor, which drive the efforts to obtain large single crystals of zinc oxide is the possibility to use the ZnO wafers as substrates for homoepitaxy and epitaxial growth of GaN layers in MBE ammonia-free methods. ZnO is a good candidate because the lattice parameters for both materials are almost the same. The preparation of substrate surface plays a crucial role in epitaxial growth applications.

This work presents a method to obtain ZnO substrates with a very smooth surface. The surface of our samples was investigated using the atomic force microscopy (AFM). We present a series of experimental results and a method based on those results to obtain surfaces with RMS= 0.5 nm. Surface of such RMS was made by short mechanical polishing with two different powders having grain size of 20-30 μm and 5-6 μm and finally by two-phase mechano-chemical polishing in colloidal silica of various pH. The first phase of mechano-chemical polishing was made in aquatic colloid solution of SiO2 nanoparticles reduced to pH=6 by hydrochloric acid. This part of polishing removes the layer degraded by mechanical polishing. The next step was polishing in colloidal solution reduced by nitric acid to pH=7. In this step we obtained very smooth surface. Short, low temperature annealing was a complementary procedure applied in order to remove the amorphous layer, keeping the roughness low.

Related papers
  1. (Cd, Mn)Te Crystals for X and Gamma Radiation Detectors - an Alternative Material to CdTe and (Cd,Zn)Te. 
  2. Improvement of the quality of polished SiC wafers using chemical oxidation and heat treatment
  3. SEM studies of the etched surface of (Cd,Mn)Te
  4. The influence of the PVT growth conditions on the SiC crystal shape
  5. Optical Characterisation of Bulk ZnO Crystals Grown by CVT
  6. Physical properties of unique ZnO single crystals from Oława Foundry
  7. Growth of SiC by PVT method with different sources of the cerium impurity, CeO2 or CeSi2
  8. The influence of growth atmosphere on the self-selection of the grains during ZnO crystal growth
  9. Ferromagnetic transition induced by re-crystallization of amorphous (Ge,Mn)Te layers
  10. Far-infrared and Raman Spectroscopy of CdTe0.97Se0.03(In)
  11. Lattice dynamics and Raman spectroscopy of ZnO:Mn crystals
  12. Influence of hydrogen on hydrogenated cadmium telluride optical spectra
  13. Additional  Phonon Modes related to intrinsic defects in CdHgTe
  14. Phonon and vibrational spectra of real crystals obtained using the synchrotron radiation
  15. ZnO homoepitaxial growth by Atomic Layer Epitaxy technique.
  16. XPS characterization of YAlO3:Co single crystals
  17. Initial Stage of SiC Crystal Growth by PVT Method
  18. Stability diagram for crystal growth from the vapor
  19. Magnetic properties of Fe doped SiC crystals
  20. Electrical contacts to semi-insulating (Cd,Mn)Te:V
  21. Influence of hydrogen on optical spectra of hydrogenated CdTe
  22. Effect of the Annealing Atmosphere on the Quality of ZnO Crystal Surface
  23. Structure properties of bulk ZnO crystals
  24. Materials requirements in the group - CdTe, CdZnTe and CdMnTe - and recent advances for X-ray and gamma-ray applications.
  25. Applications of the II-VI semimagnetic semiconductors
  26. Ferromagnetic (Eu,Gd)Te/PbTe semiconductor heterostructures
  27. Is the (Cd,Mn)Te crystal a prospective material for X-ray and γ-ray detectors?
  28. Modification of the nanostructure of the amorphised Si near-surface layer
  29. The local crystalline structure of ZnCdTe alloys obtained by Far Infrared Synchrotron Radiation measurements
  30. Defects induced by oxygen and hydrogen in CdTe crystals
  32. Structural and optical characterization of epitaxial layers of CdTe/PbTe grown on BaF2 (111) substrates
  33. Low-frequency magnons and phonons in hexagonal MnTe
  35. CVT contactless growth of ZnO crystals
  36. XPS investigations of NdGaO3 wafers
  37. Mn doped ZnTe (110) (1x1) surface in Resonant Photoemission study
  38. Differential Reflectivity and Photoemission study of ZnTe and CdTe(110) surface

Presentation: Poster at Joint Fith International Conference on Solid State Crystals & Eighth Polish Conference on Crystal Growth, by Paweł Skupiński
See On-line Journal of Joint Fith International Conference on Solid State Crystals & Eighth Polish Conference on Crystal Growth

Submitted: 2007-01-12 15:48
Revised:   2009-06-07 00:44
© 1998-2018 pielaszek research, all rights reserved Powered by the Conference Engine