Microstructural study of Mg-doped p-type GaN

Correlation between high-resolution electron microscopy and Raman spectroscopy

S. C Y Tsen, David Smith, Kong-Thon Tsen, W. Kim, H. Morkoç

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

A series of Mg-doped GaN films (∼1-1.3 μm) grown by reactive molecular beam epitaxy at substrate temperatures of 750 and 800°C has been studied by high-resolution electron microscopy (HREM) and Raman spectroscopy. Stacking defects parallel to the substrate surface were observed in samples grown on sapphire substrates at 750°C with AlN buffer layers (60-70 nm) at low Mg concentration. A transition region with mixed zinc-blende cubic (c) and wurtzite hexagonal (h) phases having the relative orientations of (111)c//(00.1)h and (110)c//(10.0)h was observed for increased Mg concentration. The top surfaces of highly doped samples were rough and assumed a completely zinc-blende phase with some inclined stacking faults. Samples grown with a Mg cell temperature of 350°C and high doping levels were highly disordered with many small crystals having inclined stacking faults, microtwins, and defective wurtzite and zinc-blende phases. Correlation between HREM and Raman scattering results points towards the presence of compressive lattice distortion along the growth direction which might be attributable to structural defects. The films grown at 800°C had better quality with less observable defects and less yellow luminescence than samples grown at 750°C.

Original languageEnglish (US)
Pages (from-to)6008-6011
Number of pages4
JournalJournal of Applied Physics
Volume82
Issue number12
StatePublished - Dec 15 1997

Fingerprint

electron microscopy
Raman spectroscopy
zinc
high resolution
crystal defects
wurtzite
spectroscopy
defects
low concentrations
sapphire
molecular beam epitaxy
buffers
luminescence
Raman spectra
temperature
cells
crystals

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physics and Astronomy (miscellaneous)

Cite this

Microstructural study of Mg-doped p-type GaN : Correlation between high-resolution electron microscopy and Raman spectroscopy. / Tsen, S. C Y; Smith, David; Tsen, Kong-Thon; Kim, W.; Morkoç, H.

In: Journal of Applied Physics, Vol. 82, No. 12, 15.12.1997, p. 6008-6011.

Research output: Contribution to journalArticle

@article{4bd8f063363b4af3857d2f140169591d,
title = "Microstructural study of Mg-doped p-type GaN: Correlation between high-resolution electron microscopy and Raman spectroscopy",
abstract = "A series of Mg-doped GaN films (∼1-1.3 μm) grown by reactive molecular beam epitaxy at substrate temperatures of 750 and 800°C has been studied by high-resolution electron microscopy (HREM) and Raman spectroscopy. Stacking defects parallel to the substrate surface were observed in samples grown on sapphire substrates at 750°C with AlN buffer layers (60-70 nm) at low Mg concentration. A transition region with mixed zinc-blende cubic (c) and wurtzite hexagonal (h) phases having the relative orientations of (111)c//(00.1)h and (110)c//(10.0)h was observed for increased Mg concentration. The top surfaces of highly doped samples were rough and assumed a completely zinc-blende phase with some inclined stacking faults. Samples grown with a Mg cell temperature of 350°C and high doping levels were highly disordered with many small crystals having inclined stacking faults, microtwins, and defective wurtzite and zinc-blende phases. Correlation between HREM and Raman scattering results points towards the presence of compressive lattice distortion along the growth direction which might be attributable to structural defects. The films grown at 800°C had better quality with less observable defects and less yellow luminescence than samples grown at 750°C.",
author = "Tsen, {S. C Y} and David Smith and Kong-Thon Tsen and W. Kim and H. Morko{\cc}",
year = "1997",
month = "12",
day = "15",
language = "English (US)",
volume = "82",
pages = "6008--6011",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics Publising LLC",
number = "12",

}

TY - JOUR

T1 - Microstructural study of Mg-doped p-type GaN

T2 - Correlation between high-resolution electron microscopy and Raman spectroscopy

AU - Tsen, S. C Y

AU - Smith, David

AU - Tsen, Kong-Thon

AU - Kim, W.

AU - Morkoç, H.

PY - 1997/12/15

Y1 - 1997/12/15

N2 - A series of Mg-doped GaN films (∼1-1.3 μm) grown by reactive molecular beam epitaxy at substrate temperatures of 750 and 800°C has been studied by high-resolution electron microscopy (HREM) and Raman spectroscopy. Stacking defects parallel to the substrate surface were observed in samples grown on sapphire substrates at 750°C with AlN buffer layers (60-70 nm) at low Mg concentration. A transition region with mixed zinc-blende cubic (c) and wurtzite hexagonal (h) phases having the relative orientations of (111)c//(00.1)h and (110)c//(10.0)h was observed for increased Mg concentration. The top surfaces of highly doped samples were rough and assumed a completely zinc-blende phase with some inclined stacking faults. Samples grown with a Mg cell temperature of 350°C and high doping levels were highly disordered with many small crystals having inclined stacking faults, microtwins, and defective wurtzite and zinc-blende phases. Correlation between HREM and Raman scattering results points towards the presence of compressive lattice distortion along the growth direction which might be attributable to structural defects. The films grown at 800°C had better quality with less observable defects and less yellow luminescence than samples grown at 750°C.

AB - A series of Mg-doped GaN films (∼1-1.3 μm) grown by reactive molecular beam epitaxy at substrate temperatures of 750 and 800°C has been studied by high-resolution electron microscopy (HREM) and Raman spectroscopy. Stacking defects parallel to the substrate surface were observed in samples grown on sapphire substrates at 750°C with AlN buffer layers (60-70 nm) at low Mg concentration. A transition region with mixed zinc-blende cubic (c) and wurtzite hexagonal (h) phases having the relative orientations of (111)c//(00.1)h and (110)c//(10.0)h was observed for increased Mg concentration. The top surfaces of highly doped samples were rough and assumed a completely zinc-blende phase with some inclined stacking faults. Samples grown with a Mg cell temperature of 350°C and high doping levels were highly disordered with many small crystals having inclined stacking faults, microtwins, and defective wurtzite and zinc-blende phases. Correlation between HREM and Raman scattering results points towards the presence of compressive lattice distortion along the growth direction which might be attributable to structural defects. The films grown at 800°C had better quality with less observable defects and less yellow luminescence than samples grown at 750°C.

UR - http://www.scopus.com/inward/record.url?scp=0031354444&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031354444&partnerID=8YFLogxK

M3 - Article

VL - 82

SP - 6008

EP - 6011

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 12

ER -