Vapor phase epitaxy growth of GaN on pulsed laser deposited ZnO buffer layer

T. Ueda, T. F. Huang, S. Spruytte, Heon Lee, M. Yuri, K. Itoh, T. Baba, J. S. Harris

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Vapor phase epitaxy (VPE) is a promising method to produce GaN substrates due to its high growth rate. In this paper, we first describe ZnO buffer layer deposition by pulsed laser deposition (PLD) on sapphire substrates for subsequent GaN VPE growth. Previously, ZnO buffer layers for GaN growth were RF-sputtered films with only poly or highly oriented crystal structure. PLD-grown ZnO buffer layers are single crystalline with streaky RHEED patterns and exhibit a sharp band-edge peak in photoluminescence. We examined the effect of ZnO buffer layer thickness on film quality of VPE-grown GaN layers on c-plane sapphire substrates. The VPE-grown GaN surfaces on ZnO buffer layers exhibit terrace-like flat surfaces, whereas three-dimensional growth with sharp rock-like structure occurs without the buffer layer. X-ray rocking curve (XRC) measurements showed that inserting the ZnO buffer reduced the GaN peak width by more than a factor of two, suggesting better crystalline quality. From the XRC measurement, buffer layers upto 50 nm thickness improve the GaN growth, while the optical properties measured by photoluminescence (PL) remain unchanged. With a 200 nm thick ZnO buffer layer, cracks occur in the subsequent GaN layer, resulting in a broader XRC peak width. In addition, the GaN film on a thick ZnO buffer shows strong peaks from donor - acceptor pair recombination and deep acceptor level from 2.6-3.2 eV in the PL spectra which are associated with Zn-doping of GaN. This implies that a thick ZnO buffer results in Zn diffusion from the buffer layer into the VPE-grown GaN film.

Original languageEnglish
Pages (from-to)340-346
Number of pages7
JournalJournal of Crystal Growth
Volume187
Issue number3-4
Publication statusPublished - 1998 May 15
Externally publishedYes

Fingerprint

Vapor phase epitaxy
Buffer layers
Pulsed lasers
vapor phase epitaxy
pulsed lasers
buffers
Photoluminescence
Buffers
Aluminum Oxide
Pulsed laser deposition
Sapphire
X rays
Substrates
photoluminescence
Crystalline materials
pulsed laser deposition
sapphire
Reflection high energy electron diffraction
curves
x rays

Keywords

  • Buffer layer
  • GaN
  • Pulsed laser deposition
  • Vapor phase epitaxy
  • ZnO

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Ueda, T., Huang, T. F., Spruytte, S., Lee, H., Yuri, M., Itoh, K., ... Harris, J. S. (1998). Vapor phase epitaxy growth of GaN on pulsed laser deposited ZnO buffer layer. Journal of Crystal Growth, 187(3-4), 340-346.

Vapor phase epitaxy growth of GaN on pulsed laser deposited ZnO buffer layer. / Ueda, T.; Huang, T. F.; Spruytte, S.; Lee, Heon; Yuri, M.; Itoh, K.; Baba, T.; Harris, J. S.

In: Journal of Crystal Growth, Vol. 187, No. 3-4, 15.05.1998, p. 340-346.

Research output: Contribution to journalArticle

Ueda, T, Huang, TF, Spruytte, S, Lee, H, Yuri, M, Itoh, K, Baba, T & Harris, JS 1998, 'Vapor phase epitaxy growth of GaN on pulsed laser deposited ZnO buffer layer', Journal of Crystal Growth, vol. 187, no. 3-4, pp. 340-346.
Ueda T, Huang TF, Spruytte S, Lee H, Yuri M, Itoh K et al. Vapor phase epitaxy growth of GaN on pulsed laser deposited ZnO buffer layer. Journal of Crystal Growth. 1998 May 15;187(3-4):340-346.
Ueda, T. ; Huang, T. F. ; Spruytte, S. ; Lee, Heon ; Yuri, M. ; Itoh, K. ; Baba, T. ; Harris, J. S. / Vapor phase epitaxy growth of GaN on pulsed laser deposited ZnO buffer layer. In: Journal of Crystal Growth. 1998 ; Vol. 187, No. 3-4. pp. 340-346.
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