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High-quality AlN growth: a detailed study on ammonia flow

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Gamze Yolcu at Sivas Cumhuriyet University
Gamze Yolcu
Merve Nur Koçak at Sivas Cumhuriyet University
Merve Nur Koçak
Dudu Hatice Ünal
Dudu Hatice Ünal
Dudu Hatice Ünal
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Ismail Altuntas
Ismail Altuntas
Ismail Altuntas
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Abstract and Figures

High crystalline and optical quality aluminum nitride (AlN) films with thin thickness have been grown on Al2O3 by MOVPE (metal-organic vapor phase epitaxy) and the NH3 flow rate has been changed to improve the morphology and quality of the films. Some characterization types of equipment such as atomic force microscopy (AFM), high-resolution X-ray diffraction (HRXRD), and Raman spectroscopy have been carried out to investigate the effect of different NH3 flow rates on surface morphology, roughness, and crystal quality of AlN, respectively. Unlike in the literature, in situ optical reflectance measurements have been given depending on NH3 flow rate and optical characterization has been performed by UV–VIS–NIR spectrophotometry. The well-defined interference patterns in the optical transmittance graph report a sharp interface between AlN and Al2O3. Also, all obtained samples have a sharp absorption edge that shows the quality of the films, but Sample B with 900 sccm NH3 flow has the sharpest absorption edge because it has high optical quality and low defect. The RMS (root mean square), DSDS{D}_{S} (screw-type dislocation density), and DEDE{D}_{E} (edge-type dislocation density) values of AlN with 900 sccm NH3 flow are 0.22 nm, 7.86 х 10⁷ , and 1.68 х 10¹⁰ cm⁻², respectively. The results obtained are comparable to the literature.
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High-quality AlN growth: a detailed study on ammonia
flow
Gamze Yolcu
1,2
, Merve Nur Koc¸ak
1,2
, Dudu Hatice U
¨nal
1,3
, Ismail Altuntas
1,3
,
Sabit Horoz
1,4
, and Ilkay Demir
1,3,
*
1
Nanophotonics Research and Application Center, Sivas Cumhuriyet University, 58140 Sivas, Turkey
2
Department of Metallurgical and Materials Engineering, Faculty of Engineering Sivas, Cumhuriyet University, 58140 Sivas, Turkey
3
Department of Nanotechnology Engineering, Faculty of Engineering, Sivas Cumhuriyet University, 58140 Sivas, Turkey
4
Department of Metallurgical and Materials Engineering, Faculty of Engineering and Natural Sciences, Sivas University of Science
and Technology, 58140 Sivas, Turkey
Received: 17 August 2022
Accepted: 21 November 2022
Published online:
25 January 2023
The Author(s), under
exclusive licence to Springer
Science+Business Media, LLC,
part of Springer Nature 2023
ABSTRACT
High crystalline and optical quality aluminum nitride (AlN) films with thin
thickness have been grown on Al
2
O
3
by MOVPE (metal-organic vapor phase
epitaxy) and the NH
3
flow rate has been changed to improve the morphology
and quality of the films. Some characterization types of equipment such as
atomic force microscopy (AFM), high-resolution X-ray diffraction (HRXRD),
and Raman spectroscopy have been carried out to investigate the effect of dif-
ferent NH
3
flow rates on surface morphology, roughness, and crystal quality of
AlN, respectively. Unlike in the literature, in situ optical reflectance measure-
ments have been given depending on NH
3
flow rate and optical characterization
has been performed by UV–VIS–NIR spectrophotometry. The well-defined
interference patterns in the optical transmittance graph report a sharp interface
between AlN and Al
2
O
3
. Also, all obtained samples have a sharp absorption
edge that shows the quality of the films, but Sample B with 900 sccm NH
3
flow
has the sharpest absorption edge because it has high optical quality and low
defect. The RMS (root mean square), DS(screw-type dislocation density), and
DE(edge-type dislocation density) values of AlN with 900 sccm NH
3
flow are
0.22 nm, 7.86 [10
7
, and 1.68 [10
10
cm
-2
, respectively. The results obtained are
comparable to the literature.
1 Introduction
AlN (aluminum nitride) has direct wide bandgap
(6.2 eV), high resistance (10
11
-10
13
Xcm), high
piezoelectric coefficient (d
33
= 5.56), high hardness
(12 GPa for the (0001) plane), and good thermal
conductivity (285 W / mK) [1–5]. Since AlN has
unique properties, it has many different application
areas, for example, ultraviolet photodetectors, light-
emitting diodes (LED), quantum cascade lasers
Address correspondence to E-mail: idemir@cumhuriyet.edu.tr
https://doi.org/10.1007/s10854-022-09556-0
J Mater Sci: Mater Electron (2023) 34:250 (0123456789().,-volV)(0123456789().,-volV)
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
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