The effect of ion implantation on structural damage in compositionally graded AlGaN layers
Compositionally graded AlₓGa₁₋ₓN alloys with the Al concentration in the (7 ≤ x ≤ 32) range were implanted with Ar+ ions to study the structural and strain changes (strain engineering). It was shown that ion implantation leads to ~0.3…0.46% hydrostatic strains and a relatively low damage of the crys...
Saved in:
| Published in: | Semiconductor Physics Quantum Electronics & Optoelectronics |
|---|---|
| Date: | 2019 |
| Main Authors: | , , , , , , |
| Format: | Article |
| Language: | English |
| Published: |
Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
2019
|
| Subjects: | |
| Online Access: | https://nasplib.isofts.kiev.ua/handle/123456789/215418 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Journal Title: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Cite this: | The effect of ion implantation on structural damage in compositionally graded AlGaN layers / O.I. Liubchenko, V.P. Kladko, H.V. Stanchu, T.M. Sabov, V.P. Melnik, S.B. Kryvyi, A.Ye. Belyaev // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2019. — Т. 22, № 1. — С. 119-129. — Бібліогр.: 40 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1860479859844710400 |
|---|---|
| author | Liubchenko, O.I. Kladko, V.P. Stanchu, H.V. Sabov, T.M. Melnik, V.P. Kryvyi, S.B. Belyaev, A.Ye. |
| author_facet | Liubchenko, O.I. Kladko, V.P. Stanchu, H.V. Sabov, T.M. Melnik, V.P. Kryvyi, S.B. Belyaev, A.Ye. |
| citation_txt | The effect of ion implantation on structural damage in compositionally graded AlGaN layers / O.I. Liubchenko, V.P. Kladko, H.V. Stanchu, T.M. Sabov, V.P. Melnik, S.B. Kryvyi, A.Ye. Belyaev // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2019. — Т. 22, № 1. — С. 119-129. — Бібліогр.: 40 назв. — англ. |
| collection | DSpace DC |
| container_title | Semiconductor Physics Quantum Electronics & Optoelectronics |
| description | Compositionally graded AlₓGa₁₋ₓN alloys with the Al concentration in the (7 ≤ x ≤ 32) range were implanted with Ar+ ions to study the structural and strain changes (strain engineering). It was shown that ion implantation leads to ~0.3…0.46% hydrostatic strains and a relatively low damage of the crystal structure. The ion-implantation leads mainly to an increase in the density of point defects, while the dislocation configuration is almost unaffected. The density of microdefects is sufficiently reduced after the post implantation annealing. The structural quality of the AlₓGa₁₋ₓN layers strongly depends on the Al concentration and worsens with increasing Al. The implantation-induced structural changes in highly dislocated AlₓGa₁₋ₓN layers are generally less pronounced. Based on the X-ray diffraction, a model is developed to explain the strain field behavior in the AlₓGa₁₋ₓN/GaN heterostructures by migration of point defects and strain field redistribution. The approach to simulate 2θ/ω scans using statistical dynamical theory of X-ray diffraction for implanted compositionally graded structures, AlGaN, has been developed.
|
| first_indexed | 2026-03-23T18:50:58Z |
| format | Article |
| fulltext |
ISSN 1560-8034, 1605-6582 (On-line), SPQEO, 2019. V. 22, N 1. P. 119-129.
© 2019, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
119
Sensors
The effect of ion implantation on structural damage
in сompositionally graded AlGaN layers
O.I. Liubchenko1,*, V.P. Kladko1, H.V. Stanchu1,2, T.M. Sabov1, V.P. Melnik1, S.B. Kryvyi1,3 and A.E. Belyaev1
1
V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine,
41, prosp. Nauky, 03680 Kyiv, Ukraine
2
Institute for Nanoscience & Engineering, University of Arkansas,
W. Dickson 731, Fayetteville, Arkansas 72701, United States
3
Institute of Physics, Polish Academy of Sciences,
Al. Lotników 32/46 PL-02-668 Warsaw, Poland
*
E-mail: lubchenco.a@gmail.com
Abstract. Compositionally graded AlxGa1–xN alloys with the Al concentration in the
(7 ≤ x ≤ 32) range were implanted with Ar
+
ions to study the structural and strain changes
(strain engineering). It was shown that ion implantation leads to ~0.3…0.46% hydrostatic
strains and a relatively low damage of the crystal structure. The ion-implantation leads
mainly to an increase of the density of point defects, while the dislocation configuration is
almost unaffected. The density of microdefects is sufficiently reduced after the post-
implantation annealing. The structural quality of the AlxGa1–xN layers strongly depends on
the Al concentration and is worsen with increasing Al. The implantation induced structural
changes in highly dislocated AlxGa1–xN layers are generally less pronounced. Based on the
X-ray diffraction, a model is developed to explain the strain field behavior in the
AlxGa1–xN/GaN heterostructures by migration of point defects and strain field redis-
tribution. The approach to simulate 2θ/ω scans using statistical dynamical theory of X-ray
diffraction for implanted compositionally graded structures AlGaN has been developed.
Keywords: AlxGa1–xN, graded layers, ion implantation, statistical X-ray diffraction theory,
microdefects.
doi: https://doi.org/10.15407/spqeo22.01.119
PACS 61.05.-a, 61.05.C-, 61.10.Nz, 61.72.-y, 68.55.Ln, 68.65.-k, 78.55.Cr, 78.70.Ck
Manuscript received 07.03.19; revised version received 21.03.19; accepted for publication
27.03.19; published online 30.03.19.
1. Introduction
The wide range of direct band gaps of AlGaN alloys
(from 3.4 to 6.2 eV) and the presence of strong electronic
polarization fields [1] are attractive properties for the
development of various optoelectronic devices. In
particular, the recently demonstrated polarization-
induced doping in III-nitrides was shown to effectively
enhance the p-type conductivity of the AlGaN layers [2],
which was successfully exploited for fabrication of light
emitting diodes (LEDs) [2] and p-n junction devices [3].
At the same time, the ion implantation technique is more
attractive for selective area doping and implant isolation
[4].
It is well known that the implantation process leads
to severe deterioration of the crystalline quality and
accumulation of large lattice strains. These effects were
extensively studied in the past for AlN and GaN
semiconductors [5, 6], and it was shown that damage and
strain buildup with increasing the ion dose until
amorphization. The implantation damage is partially
reduced after the post implantation high-temperature
annealing, which is performed for donor/acceptor
activation.
The recent studies on the process of ion
implantation in ternary Al0.44Ga0.56N layers have shown a
multi-step damage accumulation with increasing the
implantation fluence, and the transition threshold of the
defects buildup increasing with AlN molar fraction [7].
No amorphization was reported for the AlGaN alloys
implanted with Ar
+
ions at 320 keV. The accumulation of
implantation damage in AlxGa1–xN alloys was also
investigated in Ref. [8] for Al0.15Ga0.85N and
Al0.77Ga0.23N layers implanted under random and
channeled geometries with Tm
+
ions. The damage level
was shown to be lower for channeling implantation, and
like in Ref. [7] the damage behavior was distinct for the
alloys with different AlN molar fractions. Specifically, it
SPQEO, 2019. V. 22, N 1. P. 119-129.
Liubchenko O.I., Kladko V.P., Stanchu H.V. et al. The effect of ion implantation on structural damage …
120
was shown that surface regions with lower damage levels
form for AlGaN layers with higher AlN molar fractions.
Similar behavior of the bimodal damage was also
demonstrated in Ref. [9] for AlxGa1–xN alloys (x = 0,
0.13, 0.47, 0.7, and 1) implanted with Ar
+
ions. In
addition, the X-ray diffraction (XRD) analysis has shown
that the implantation with Ar
+
ions introduces hydrostatic
strain resulting from the expansion of the c-lattice
parameter. Saturation of the strain was suggested to
occur in alloys implanted at high ion fluences.
In this work, a detailed XRD study of the effect of
ion implantation and post implantation annealing on the
structural damage and strain state is presented for
compositionally graded AlxGa1–xN layers. The
implications of the described results are important for
further understanding of the processes of implantation
damage in III-nitride alloys with compositional gradients.
2. Experiment
The AlxGa1–xN layers were grown in a Veeco Gen-II
plasma-assisted molecular beam epitaxy (PAMBE)
system on commercial substrates consisting of ~5 µm of
(0001) oriented GaN on AlN/sapphire. First, the 400-nm
thick GaN buffer layer was grown under gallium-rich
conditions at a substrate temperature of 690 °C. Next, the
substrate temperature was raised up to 710 °C, and
compositionally graded AlxGa1–xN layers were grown by
linearly changing the temperature of the Al effusion cell
[10]. The AlN molar fraction in the AlxGa1–xN layers was
graded from ~7 up to ~22% (sample S1) and from ~7 up
to ~32% (sample S2). Implantation was performed at
room temperature at the angle 7°. Both samples were
implanted with Ar
+
ions in two steps. For each step, the
implantation energy and dose were 100 keV and
1×10
14
at./cm
–2
, respectively. The high-temperature
annealing was performed at ~750 °C for 15 min. The
samples were investigated with high-resolution X-ray
diffraction (HRXRD) using PANalytical X’Pert Pro
MRD XL diffractometer equipped with the CuKα1
radiation (λ = 0.154056 nm), four-bounce (220) Ge
monochromator, and three-fold (022) Ge analyzer.
3. Theory
To simulate X-ray diffraction spectra, we use the
statistical dynamical theory of X-ray diffraction
developed in Refs. [11–13] for uniform epitaxial films
with randomly distributed microdefects. The coherent
part of the diffracted intensity from a uniform crystalline
layer is based on solution of the equations for the
coherent and diffuse waves [11] under the condition
0=u (where u is the statistical average of the
displacement of the atoms from their positions in a
perfect lattice [11, 13, 14]).
In the case of symmetric Bragg diffraction, the
diffracted (
c
gE ) and transmitted amplitudes ( cE0 ) of
X-ray waves from a plane-parallel plate of thickness l are
given as [11]:
( ) ( )[ ]( ) ( ) QzizlizE c
1210 expexp εξ−−ξξ= , (1)
( ) ( )[ ]( ) ( ) QzizliEzE g
c
g 1exp1exp ε−−ξσ= , (2)
where z is the depth coordinate.
The amplitude coefficients of the reflected r and
transmitted t waves through a layer of the thickness l are
[11]:
( )( ) QilEr g
g
1exp −ξσ= ±
±
, (3)
( ) Qlit 1exp εξ= , (4)
( ) Qlit g
2exp ε−ξ=− , (5)
where, [11], ( ) 21 exp ξ−ξξ= ilQ , ( ) 22,1 ξ±η−=ξ d ,
22
4σ−η=ξ d , ggE −σσ=σ 22
, 2,102,1 ξ+ψ+σ=ε i ,
ψ+η=η 2id , ( )τ−σσ=ψ −
2
1 Egg ,
( )[ ] ( )000 2sin2 λγθθ∆+χπ=η , ( )000 λγπχ=σ ,
( )0,ggg c γλχ=σ ±± . Here, E is the static Debye–Waller
(D-W) factor, λ – X-ray wavelengths, γ0 and γg are
direction cosines, χ0, χg, χ–g – electric susceptibilities,
which are related to the structure factor of the crystal unit
cell, c is the polarization factor, θ – angle of incidence,
θ0 – Bragg angle, 0θ−θ=θ∆ – deviation from the exact
Bragg position.
The X-ray diffraction spectra from the
AlxGa1–xN/GaN heterostructures were calculated using
the recursive formula approach. Accordingly, the
amplitude coefficients of reflected Rn and transmitted Tn
waves in the n-th layer of a multilayered system are
given as follows [11]:
g
n
g
n
g
n
g
nng
n
g
n
rR
Rtt
rR
−
−
−
−
−
+=
1
1
1
,
g
n
g
n
nn
n
rR
tT
T
−
−
−
−
=
1
1
1
. (6)
In more details, to obtain the diffracted intensity,
the AlxGa1–xN/GaN heterostructure is first separated by n
sublayers. Then, this calculation starts from the substrate,
and the recursion equations are used successively for
each sublayer until the surface of the sample. Finally, the
coherent part of the diffracted intensity is given by:
2
n
c
g RI = . (7)
Reduction of diffracted intensity due to
displacement fields u associated with microdefects is
accounted by using the static Debye–Waller factor E [11,
13, 14]:
( )ugiE
rr
δ= exp , (8)
where g
r
is the diffraction vector.
SPQEO, 2019. V. 22, N 1. P. 119-129.
Liubchenko O.I., Kladko V.P., Stanchu H.V. et al. The effect of ion implantation on structural damage …
121
The randomly distributed spherically symmetric
defects, which have zero deformation fields outside the
cluster [11, 14–16], are considered to generalize the types
of point defects and to describe the microdefect structure
of the ion-implanted samples.
The displacement field for randomly distributed
spherically symmetric defects [11, 14–16] is given by:
( )
≤
>
=δ
d
d
Rr
Rr
ru r
r
r
ifvalue,random
if,0
(9)
The concentration of point defects in the AlxGa1–xN
layers implanted with Ar
+
ions is commonly higher than
in GaN bulk material [17, 18], and for the mentioned
implantation energy and doses is expected to be at the
order of 10
19
сm
–3
[19, 20].
Then, the static D-W factor is given by [11,14,16]:
π
−= 3
3
4
exp dd RCE (10)
and, for low defect concentrations E is reduced to [16]:
3
3
4
1 dd RCE
π
−= . (11)
Here, Cd and Rd are the concentration and
microdefect radius, respectively.
The correlation length τ is the main parameter of
statistical theory of X-ray diffraction, which determines
the defect related diffuse scattering [11, 14, 15]:
( ) ( )∫
∞
ςςης=τ
0
exp dgi , (12)
where ( )ςg is the correlation function [11, 13, 16].
In general, there are few types of spherical-
symmetric microdefects, each requiring unique
expressions for the correlation functions [13, 14, 16]. In
this work, for the sake of simplicity the correlation
function was generalized by the Gaussian function [13,
16]:
( )
τ
πς
=ς
0
2
4
expg , (13)
which leads to the correlation length in the form of [13,
15]:
( ) ( )[ ]iyerfy +⋅−τ=τ 1exp 2
0 , (14)
where πητ= 0y and 0τ is the Kato correlation length
[21].
Considering the mentioned above spherically
symmetric defects, the following relation is obtained
between the correlation length 0τ and defect radius Rd
[14, 15]:
00
4
3
γ=τ dR , (15)
where ( )00 sin θ=γ .
Also, taking into account Eqs. (11) and (15), the
defect radius (Rd) and concentration of defects (Cd) can
be determined as follows:
( )0
0
sin3
4
θ
τ
=dR , (16)
( )( ) ( )
3
0
3
0 1sin
64
81
πτ
−⋅θ
=
E
Cd . (17)
Finally, within the kinematical approximation, the
diffuse part of the diffracted intensity is given by [13,
15]:
( ) ( ) lEI g
d
g ⋅τ⋅−σ= Re12 22
. (18)
4. Results and discussion
The reciprocal space maps (RSMs) were measured
around the asymmetrical ( 5220 ) reflection to study
the epitaxial relationship in the ion-implanted
GaN/AlxGa1–xN heterostructures after implantation and
annealing processing. The ( 5220 ) RSMs of samples S1
and S2 are shown in Figs. 1a-d and Figs. 1e-h,
respectively. The Qx coordinate is inversely related to the
lattice parameter a and Qz – to the parameter c on RSMs.
The most intensive peak and the elongated vertical
streaks above it are attributed to the undamaged part of
the GaN substrate and the compositionally graded
AlxGa1–xN layer, respectively. Implantation with Ar
+
ions
introduces expansion of the lattice parameter c, which is
reflected in a downward shift of both the AlxGa1–xN
peaks and streak below the GaN peak (Figs. 1b, 1c, 1f
and 1g). The second implantation has induced an extra
downward Qz shift only for the AlxGa1–xN peaks (Fig. 1c
and 1g), which means increasing of the lattice parameter
c. In addition, RSMs shows fully strained graded layer to
GaN substrate at all the processing stages. Also, after
each processing stage, there are no visible Qx shift of the
AlxGa1–xN and GaN peak position, which indicates that
implantation does not introduce notable strain along the
a-axis of the crystal lattice. It is in agreement with
previous reports [8, 22–24]. The high-temperature
annealing resulted in a remarkable lattice recovery;
however, some residual с-lattice extension is still
observed in both the GaN and AlxGa1–xN layers (Fig. 1d
and 1h).
SPQEO, 2019. V. 22, N 1. P. 119-129.
Liubchenko O.I., Kladko V.P., Stanchu H.V. et al. The effect of ion implantation on structural damage …
122
The HRXRD 2θ/ω scans were measured around the
symmetrical (0002) reflection to investigate in more
details the implantation damage in the compositionally
graded layers. The scattered intensity near the low-order
reflection is generally characterized with higher intensity
contrast between the interference fringes and background
level, which is important for retrieving reliable data. For
the samples S1 and S2, the measured (grey circles)
(0002) 2θ/ω scans are shown in Fig. 2. The most intense
peak on the HRXRD spectra corresponds to the
undamaged GaN substrate. The peaks from the graded
AlxGa1–xN layer appear in the form of interference
fringes at the right side of the sharp GaN peak. Ion-
implantation resulted in an extension of the GaN and
AlxGa1–xN peaks toward the lower angles, which is
almost fully recovered after the high-temperature
annealing. Since the extension at the left side of the GaN
peak also vanishes, this additionally confirms its strain
nature. The (0002) 2θ/ω scans were simulated to compare
the strain in the AlxGa1–xN/GaN heterostructures after the
implantation with different Ar
+
doses.
The depth profiles of Al concentration in the
AlxGa1–xN layers of the as-grown samples S1 and S2
(insets in Fig. 2) were previously determined in Ref. [10]
and are used in this work to study the effect of ion
implantation on the strain distribution in the
AlxGa1–xN/GaN heterostructures. It is well known that
ion implantation is accompanied with formation of a high
density of point defects, which generally leads to a
vertical hydrostatic expansion of the unit cell (Fig. 1).
To simulate 2θ/ω scans, the hydrostatic strain in the
AlxGa1–xN and GaN buffer layers was approximated with
Fig. 1. ( 5220 ) RSMs of the samples S1 (a-d) and S2 (e-h) measured at the different processing stage: (a, e) as-grown, (b, f) after the
first implantation, (c, g) after the second implantation, and (d, h) after the high-temperature annealing.
SPQEO, 2019. V. 22, N 1. P. 119-129.
Liubchenko O.I., Kladko V.P., Stanchu H.V. et al. The effect of ion implantation on structural damage …
123
the two-piece normal distribution (Eq. (19)), which is
often used to fit the strain distribution in the ion-
implanted layers [25], and an exponential function
(Eq. (20)), respectively:
ρ>
ρ≤
=
Ω
ρ−
−=
∆
z
z
i
z
Τ
d
d
i ,2
,1
,
2
exp
2
AlGaN
(19)
( )zkk
d
d
21
GaN
exp −=
∆
. (20)
Here, ρ is the implanted range, 1Ω and 2Ω are the left-
and right-hand-side standard deviations, Τ is the peak
strain value, k1 and k2 are fitting parameters, and z is the
distance from the sample surface.
The differential evolution method [27, 28] allows
one to minimize the deviation between two profiles and
was employed for XRD 2θ/ω scans fitting. The error
between the experimental and calculated 2θ/ω scans was
determined as in Refs. [29, 30]. For the samples under
investigation, the fitting is additionally complicated by
the low intensity of the fringes from the AlxGa1–xN layer
and the relatively high intensity from the peak at the
lower angles from the GaN substrate.
The widely used minimization criteria, such as
mean-absolute error [27], relative error [27], and those
described in Refs. [31–33], does not allow a good fitting
of the entire XRD 2θ/ω scan, which is even more
complicated when considering the diffuse scattering.
Therefore, we first fitted the part of the 2θ/ω scan
associated with the AlxGa1–xN layer, assuming the strain
profiles, the static D-W factor, and the Kato correlation
length in the form of two-sided Gaussian functions
similar to those for the strain distribution (Eq. (19)). The
profiles of the static Debye–Waller factor and the Kato
correlation length were characterized with a common
maximum. Second, the fitting criterion between the
measured and simulated spectra is given as follows [30]:
∑ −=
N
K
II
N
Err calcexp
1
, (21)
where the user specified value of K is limited within
[0.1–0.9]. For small and large values of K, a good fitting
is achieved for the low and high intensity features of the
2θ/ω scan, respectively. When using the abovementioned
17.1 17.2 17.3 17.4 17.5 17.6
9 12 15 18 21
0
30
60
90
120
150
180
Simulated
Experimental
Initial
(a) sample S1
1st implantation
GaN
GaN buffer
2nd implantation
In
te
n
s
it
y
,
a
rb
.
u
n
it
s
θ, θ, θ, θ, deg
Annealed
AlGaN
T
h
ic
k
n
e
s
s
,
n
m
Al, %
17.1 17.2 17.3 17.4 17.5 17.6 17.7
5 10 15 20 25 30 35
0
30
60
90
120
150
180
Simulated
Experimental
Initial
(b) sample S2
GaN
GaN buffer
1st implantation
2nd implantation
In
te
n
s
it
y
,
a
rb
.
u
n
it
s
AlGaN
θ, θ, θ, θ, deg
Annealed
T
h
ic
k
n
e
s
s
,
n
m
Al, %
Fig. 2. Measured (gray circles) and simulated (red lines) (0002) 2θ/ω scans of the samples S1 (a) and S2 (b). The insets show the
depth profiles of Al concentration in the AlxGa1–xN layers of samples S1 and S2.
SPQEO, 2019. V. 22, N 1. P. 119-129.
Liubchenko O.I., Kladko V.P., Stanchu H.V. et al. The effect of ion implantation on structural damage …
124
criteria [27] with K = 1 and K = 2, the best fit is achieved
near the peak of the GaN substrate, where the intensity is
high. However, the fitting of the AlxGa1–xN layer is
generally poor. Therefore, the AlxGa1–xN peak was first
fitted separately, using [ ]65.05.0 −≈K , while the
parameters k1 and k2 in (Eq. (20)) were kept fixed. After
this, the determined fitting parameters for the AlxGa1–xN
layer were fixed, and the peak for the GaN buffer layer
was fitted by changing k1 and k2 in Eq. (20). For the GaN
buffer, the values of K were given both larger [0.7–0.8]
and lower [0.2–0.5] than for the AlxGa1–xN layer. The
mutual influence of small changes in the fitting
parameters of the two-step fitting process on the XRD
spectra is small and can be neglected.
The deviation between the experimental and
calculated XRD spectra is estimated using the following
relative error:
∑
−
=
N
calc
rel
I
II
N
Err
exp
exp1
(22)
The relative error of the performed fitting did not
exceed 40% for the sample S1 and 48% for the sample
S2.
The depth profiles of strain in the AlxGa1–xN/GaN
heterostructures obtained from the simulations are shown
in Fig. 3. The AlxGa1–xN layers of the as-grown samples
are under compressive strain (εc) along the c-axis due to
the tensile biaxial strain (εa) in the (0001) basal plane
induced by the constant in-plane lattice parameter. The
observed jump of εc at the AlxGa1–xN/GaN interface
results from the fact that the grading of Al concentration
in the AlxGa1–xN layer starts from about 7%, resulting in
the ~0.17% lattice misfit at the AlxGa1–xN/GaN interface.
After the implantation, an almost uniform depth
distribution of hydrostatic strain in the AlxGa1–xN layers
the most correctly describes the AlxGa1–xN peaks on the
(0002) 2θ/ω scan. This is despite the high implantation
energy (100 keV) that should have resulted in the
maximum concentration of Ar
+
at the depth of about
90 nm from the surface [19], which is often reported for
ion implantation into single crystals [26]. The strain in
the GaN buffer increases only after the implantation with
the first dose of Ar
+
ions and is not affected by the
second dose. Like to that in the AlxGa1–xN layer, the
strain in the GaN buffer is almost totally reduced after
the sample annealing.
Fig. 4 shows the averaged over the sample area
depth profiles of the static Debye–Waller factor (E) and
of the Kato correlation length (τ0) for the sample S1. The
shape of these profiles is very close to that of the
demonstrated in Fig. 3 (inset) hydrostatic strain. The
detailed analysis of the XRD spectra inherent to the
samples S1 and S2 suggest the presence of few types of
microdefects. For example, the microdefects of small and
large radius have a dominant effect on the spectra tail far
and close to the Bragg position, respectively [34].
However, consideration of more types of microdefects
sufficiently complicates the XRD spectra fitting and
interpretation of results. Therefore, we consider only one
dominant type of microdefects, which is characterized
with some averaged across the layer parameters of the
D-W factor, correlation length, as well as their depth
distribution.
Fig. 5 shows the microdefects radii and
concentrations, which were calculated according to
Eqs. (16) and (17) and averaged over the compositional
gradient layer thickness. A higher concentration of
defects with smaller radius is seen by comparing the
Fig. 3. The depth profiles of strain in the samples S1 (a) and S2 (b). The inset shows the hydrostatic strain in the AlxGa1–xN layers
after the implantation and annealing processes.
SPQEO, 2019. V. 22, N 1. P. 119-129.
Liubchenko O.I., Kladko V.P., Stanchu H.V. et al. The effect of ion implantation on structural damage …
125
Fig. 4. Depth profiles of the static Debye–Waller factor E (a)
and Kato correlation length τ0 (b) for the sample S1.
as-grown samples S2 and S1, which can be explained by
the higher Al concentration in the AlxGa1–xN layer of the
sample S2. After ion implantation, the average defect
size decreases with simultaneous increase of the defect
concentration, and which is most noticeably observed for
the sample S1. It should be noted that due to the high
crystalline quality of the samples S1 and S2, the coherent
part of diffracted intensity dominates over the diffuse
component, which reduces the accuracy of determined
depth profiles of the static D-W factor and radii of
defects [35]. After the high-temperature annealing, the
average microdefect size increases sufficiently. Also, for
both samples the average concentration of defects is
almost the same and lower than for the as-grown sample.
III-nitride heterostructures are commonly character-
rized with a high density of dislocations (10
8
–10
10
cm
–2
),
and the effect of dislocations is higher for XRD spectra
measured for high-order reflections. To simulate XRD
spectra for investigated ion-implanted structures, the
dislocations were included into the static Debye–Waller
factor along with the point defects. However, for
simplicity it was assumed that the diffuse scattering was
caused solely by point defects. Moreover, the
dislocations broadening of (0002) 2θ/ω scans is small in
comparison with high-order reflections [29]. This also
explains the weaker change of the microdefect state
of the sample S2 in comparison with the sample S1. The
0
1000
2000
3000
4000
5000
6000
1E12
1E13
1E14
R
a
d
iu
s
o
f
d
e
fe
c
ts
,
Å
Sample S1
Sample S2
1st
impl.
2nd
impl.
Annealed
C
o
n
c
e
tr
a
ti
o
n
o
f
d
e
fe
c
ts
,
1
/c
m
3
Initial
Fig. 5. The average defect radius Rd and concentration of
defects Cd in the AlGaN layers of the samples S1 and S2 after
the growth, implantation and annealing stages.
defect concentration in the as-grown sample S2 is higher
due to the higher Al concentration in the AlxGa1–xN layer,
and higher lattice mismatch [10].
For perfect single crystals, the high-temperature
processes, such as annealing, lead to generation of
dislocation loops and defect agglomeration. However, for
highly-dislocated crystals, the high-temperature
annealing causes changes in dislocation configuration
and their gliding with simultaneous change of the
microdefect concentration [36, 37].
The triple-crystal (0002) ω-scans were measured at
the Bragg positions of the GaN substrate and AlxGa1–xN
layer to additionally study the type of defects introduced
by ion implantation. Fig. 6 compares the double
logarithmic plots of the (0002) ω-scans for the initial and
Ar
+
-implanted sample S2. The broadening normal to the
diffraction vector reflects the defect structure of the
sample and for high-quality crystalline materials is
determined by instrumental factors. Commonly, the slope
of line shapes at the tail region follows the power law
nI −θ∆~ for both ω and 2θ/ω scan types. Depending on
the type of defects, n can vary between 2 and 5. Thereby,
for epitaxial layers containing ordered threading
dislocations, the double-crystal and triple-crystal
measurements shows n = 3 and n = 4, respectively [38].
This was previously theoretically calculated by
Kryvoglaz and then developed in the works of Kaganer
SPQEO, 2019. V. 22, N 1. P. 119-129.
Liubchenko O.I., Kladko V.P., Stanchu H.V. et al. The effect of ion implantation on structural damage …
126
Fig. 6. Triple-crystal (0002) ω-scans in the log-log scale
measured for GaN substrate, and AlxGa1–xN layer for the
initial state and after the second stage of implantation in the
sample S2.
-4.00
-3.75
-3.50
-3.25
-3.00
-2.75
-2.50
-2.25
-2.00
-1.75
2nd
impl.
P
o
w
e
r
n
i
n
I
=
( ∆
ω
∆
ω
∆
ω
∆
ω
)n
AlGaN (Sample 1) AlGaN (Sample2)
GaN (Sample 1) GaN (Sample 2)
Initial 1st
impl.
Anneal
Fig. 7. The slope of the tail region determined from the (0002)
ω-scans of GaN buffer and AlGaN layer from the samples S1
and S2.
AlGaN (S1)
AlGaN (S2)
GaN (S1)
GaN (S2)
260
280
300
320
340
Anneal
2nd
impl.
1st
impl.
F
W
H
M
,
a
rc
s
e
c
Initial
Fig. 8. FWHM of the (0002) ω-scans measured for the
AlxGa1–xN layers and GaN substrates of the samples S1 and S2.
et al. [39]. Additionally, Barchuk et al. [40] have shown
that n can vary between 2 and 3, depending on the type
of threading dislocations (screw or edge).
For epitaxial layers containing random dislocations,
the intensity decay at the tail region of the (0002) ω-scan
is generally faster than for layers with threading pure
screw dislocations [38]. It should be mentioned that for
high densities of dislocations the behavior of intensity
decay does not depends on the dislocations density but is
defined solely by the dislocation type [38]. Additionally,
due to the high densities of dislocations in as-growth
non-implanted III-nitrides, the influence of point defects
on the intensity decay is commonly neglected.
The slope of the tail region determined from the
(0002) ω-scans of the samples S1 and S2 are plotted in
Fig. 7. It can be seen that the slope of the intensity decay
for the GaN template is about 3.75…3.88 for the sample
S1 and about 3.6…3.8 for the sample S2, and only
slightly changes after the high-temperature annealing.
The slope for the AlxGa1–xN layer is about 3.25 and 3.05
for the samples S1 and S2. The slope is only slightly
affected by the implantation and annealing processes.
Therefore, it may be concluded that the ion implantation
does not sufficiently affect the dislocation configuration
of the AlxGa1–xN/GaN heterostructure.
The full width of half maximum (FWHM) of ω-
scans for symmetrical (0002) reflection is commonly
measured to estimate the density of screw-type
dislocations [10]. FWHMs for the AlxGa1–xN layers and
GaN substrates of the samples S1 and S2 are shown in
Fig. 8, and compared for the as-grown, ion-implanted,
and annealed stages. It can be seen that the density
of screw-type dislocation is lower in the GaN and
AlxGa1–xN layers of the sample S1, which has a lower Al
concentration in the AlxGa1–xN layer. The density of
screw-type dislocations in the AlxGa1–xN layers is about
1.35·10
8
cm
–2
and 2.1·10
8
cm
–2
for the samples S1 and
S2, respectively [10]. FWHM increases after the first
implantation and only slightly – after the second
implantation step. The increase of the dislocation density
at room temperature is unlikely, and the increase of the
FWHM is probably related with the increase of the
concentration of point defects and the change of the
strain state in the sample. FWHM sufficiently decreases
after the high-temperature annealing, which indicate the
reduced concentration of point defects induced by
implantation and small changes in the dislocation
concentration. The nature of broadening of the GaN
substrate peak is different from that of the AlxGa1–xN
layer. It was shown in Ref. [19] that implantation in the
upper part of an AlN/GaN SL also leads to an increase of
the defect concentration in the buffer layer, which can be
explained by the strain and microdefects redistribution in
the sample. This also can be attributed to the samples S1
and S2 to explain the ω-scan broadening by the strain
distribution and defect migration in the Al2O3-GaN
substrate-GaN buffer-compositional gradient layer.
5. Conclusions
In this work, the compositionally graded AlxGa1–xN/GaN
heterostructures were implanted with Ar
+
ions to study
the possibility of strain engineering. A method was
developed to retrieve the profiles of strains and those of
the fluctuational displacements of atoms caused by the
presence of microdefects in a crystalline film by
SPQEO, 2019. V. 22, N 1. P. 119-129.
Liubchenko O.I., Kladko V.P., Stanchu H.V. et al. The effect of ion implantation on structural damage …
127
simulating the XRD spectra from the ion-implanted
heterostructures with including the diffuse scattering. It
was shown that ion implantation with doses and energy
of about (1…2)·10
14
cm
–2
and 100 keV does can induce
large values of hydrostatic strain ~0.3…0.46% and
relatively low damage of the crystalline lattice. Ion
implantation influences mainly on the density of point
defects, while the dislocation configuration is almost
unaffected. The density of microdefects is sufficiently
reduced after the post-implantation annealing facilitated.
The structural perfection of the AlxGa1–xN layers
strongly depends on the Al concentration, and is reduced
with increased Al. The structural changes induced by ion
implantation in highly defected samples are less
pronounced. Ion-implantation leads to ω-scans
broadening from both the AlxGa1–xN and GaN layers,
which can be explained by migration of the point defects
and redistribution of strain fields within the
heterostructure. Due to the high density of dislocations in
III-nitrides, the microdefect structure can be better
distinguished for the ion-implanted samples with ultra-
low density of dislocations.
References
1. Jena D., Heikman S., Green D., Buttari D., Coffie
R., Xing H., Keller S., DenBaars S., Speck J.S.,
Mishra U.K. and Smorchkova I. Realization of wide
electron slabs by polarization bulk doping in graded
III-V nitride semiconductor alloys. Appl. Phys. Lett.
2002. 81, No. 23. P. 4395–4397.
doi: 10.1063/1.1526161.
2. Simon J., Protasenko V., Lian C., Xing H. and Jena
D. Polarization-induced hole doping in wide-band-
gap uniaxial semiconductor heterostructures.
Science. 2010. 327, P. 60–64.
doi: 10.1126/science.1183226.
3. Li S., Ware M., Wu J., Minor P., Wang Z., Wu Z.,
Jiang Y. and Salamo G. J. Polarization induced pn-
junction without dopant in graded AlGaN
coherently strained on GaN. Appl. Phys. Lett. 2012.
101, No. 12. P. 122103. doi: 10.1063/1.4753993.
4. Tadjer M.J., Feigelson B.N., Greenlee J.D., Freitas
J.A., Anderson T.J., Hite J.K., Ruppalt L., Eddy
C.R., Hobart K.D. and Kub F.J. Selective p-type
doping of GaN:Si by Mg ion implantation and
multicycle rapid thermal annealing. ECS J. Solid
State Sci. Technol. 2016. 5, No. 2. P. 124–127. doi:
10.1149/2.0371602jss.
5. Liu C., Mensching B., Volz K. and Rauschenbach
B. Lattice expansion of Ca and Ar ion implanted
GaN. Appl. Phys. Lett. 1997. 71, No. 16. P. 2313–
2315. doi: 10.1063/1.120059.
6. Liu C., Mensching B., Zeitler M., Volz K. and
Rauschenbach B. Ion implantation in GaN at liquid-
nitrogen temperature: Structural characteristics and
amorphization. Phys. Rev. B. 1998. 57, No. 4. P.
2530–2535.
doi: 10.1103/PhysRevB.57.2530.
7. Pagowska K., Ratajczak R., Stonert A., Nowicki L.
and Turos A. Compositional dependence of damage
buildup in Ar-ion bombarded AlGaN. Vacuum.
2009. 83. P. S145–S147.
doi: 10.1016/j.vacuum.2009.01.048.
8. Fialho M., Magalhães S., Chauvat M. P., Ruterana
P., Lorenz K. and Alves E. Impact of implantation
geometry and fluence on structural properties of
AlxGa1–xN implanted with thulium. J. Appl. Phys.
2016. 120, No. 16. P. 165703.
doi: 10.1063/1.4966120.
9. Faye D.N., Alves E., Felizardo M., Wendler E.,
Brunner F., Lorenz K., Magalhães S. and Weyers
M. Mechanisms of implantation damage formation
in AlxGa1– xN compounds. J. Phys. Chem. C. 2016.
120, No. 13. P. 7277–7283.
doi: 10.1021/acs.jpcc.6b00133.
10. Kuchuk A.V., Lytvyn P.M., Li C., Stanchu H.V.,
Mazur Y.I., Ware M.E., Benamara M.,
Ratajczak R., Dorogan V., Kladko V.P., Belyaev
A.E. and Salamo G.G. Nanoscale electrostructural
characterization of compositionally graded
AlxGa1–xN heterostructures on GaN/sapphire (0001)
substrate. ACS Appl. Mater. Interfaces. 2015. 7, No.
41. P. 23320–23327. doi: 10.1021/acsami.5b07924.
11. Punegov V.I. X-Ray diffraction from multilayer
structures with statistically distributed microdefects.
phys. status solidi (a). 1993. 136, No. 1. P. 9–19.
doi: 10.1002/pssa.2211360102.
12. Punegov V.I. Dynamic X-ray diffraction in layered-
inhomoneous systems. Tech. Phys. Lett. 1994. 20,
No. 1. P. 58–59.
13. Punegov V.I., Petrakov A.P. and Tikhonov N.A.
X-ray diffraction on laser disturbed near-surface
crystal layers. phys. status solidi (a). 1990. 122, No.
2. P. 449–458. doi: 10.1002/pssa.2211220202.
14. Pavlov K.M. and Punegov V.I. Der einfluß
kugelsymmetrischer kristalldefekte auf die
winkelverteilung gebeugter röntgenstrahlung. phys.
status solidi (a). Basic Res. 1997. 199, No. 1. P. 5–
14. doi: 10.1002/1521-3951(199701)199:1<5::AID-
PSSB5>3.0.CO;2-V.
15. Punegov V.I. and Pavlov K.M. Models of
spherically symmetric microdefects in the statistical
dynamical theory of diffraction: II. Correlation
length. Crystallogr. Reports. 1996. 41, No. 4. P.
585–591.
16. Punegov V.I. and Pavlov K.M. Models of Sphe-
rically Symmetric Microdefects in the Statistical
Dynamical Theory of Diffraction: I. Correlation
Function. Crystallogr. Reports. 1996. 41, No. 4.
P. 575–584.
17. Boguslawski P., Briggs E.L. and Bernholc J. Native
defects in gallium nitride. Phys. Rev. B.
1995. 51, No. 23. P. 17255–17258.
doi: 10.1103/PhysRevB.51.17255.
18. Fehrer M., Einfeldt S., Birkle U., Gollnik T. and
Hommel D. Impact of defects on the carrier
transport in GaN. J. Cryst. Growth. 1998. 189–190.
P. 763–767. doi: 10.1016/S0022-0248(98)00284-X.
SPQEO, 2019. V. 22, N 1. P. 119-129.
Liubchenko O.I., Kladko V.P., Stanchu H.V. et al. The effect of ion implantation on structural damage …
128
19. Liubchenko O.I., Sabov T.M., Kladko V.P., Melnik
V.P., Yukhymchuk V.O., Romaniuk B.M.,
Kolomys O., Hreshchuk O., Dubikovskyi O.V.,
Maksymenko Z.V., Gudymenko O.Yo. and Belyaev
A.E. Modification of elastic deformations and
analysis of crystalline changes in Ar
+
-implanted
AlN/GaN superlattices. Appl. Nanosci. 2019. 9. doi:
10.1007/s13204-019-01000-w.
20. Ziegler J.F., Ziegler M.D. and Biersack J.P. SRIM –
The stopping and range of ions in matter (2010).
Nucl. Instruments Methods Phys. Res. Sect. B Beam
Interact. with Mater. Atoms. 2010. 268, No. 11-12.
P. 1818–1823. doi: 10.1016/j.nimb.2010.02.091.
21. Kato N. Statistical dynamical theory of crystal
diffraction. I. General formulation. Acta
Crystallogr. Sect. A. 1980. 36, No. 5. P. 763–769.
doi: 10.1107/S0567739480001544.
22. Pipeleers B., Hogg S. M. and Vantomme A. Defect
accumulation during channeled erbium implantation
into GaN. J. Appl. Phys. 2005. 98, No. 12. P.
123504. doi: 10.1063/1.2143120.
23. Fialho M., Rodrigues J., Magalhães S., Correia M.
R., Monteiro T., Lorenz K. and Alves E. Effect of
AlN content on the lattice site location of terbium
ions in AlxGa1−xN compounds. Semicond. Sci.
Technol. 2016. 31, No. 3. P. 035026.
doi: 10.1088/0268-1242/31/3/035026.
24. Magalhães S., Fialho M., Peres M., Lorenz K. and
Alves E. Quantitative x-ray diffraction analysis of
bimodal damage distributions in Tm implanted
Al0.15Ga0.85N. J. Phys. D. Appl. Phys. 2016. 49,
No. 13. P. 135308.
doi: 10.1088/0022-3727/49/13/135308.
25. Klappe J.G.E. and Fewster P.F. Fitting of rocking
curves from ion-implanted semiconductors. J. Appl.
Crystallogr. 1994. 27. P. 103–110.
doi: 10.1107/S0021889893007484.
26. Arulkumaran S., Kennedy J., Bhat T.N., Ng G.I.,
Ranjan K., Tripathy S. and Murmu P.P. Thermally
stable device isolation by inert gas heavy ion
implantation in AlGaN/GaN HEMTs on Si. J. Vac.
Sci. Technol. B, Nanotechnol. Microelectron.
Mater. Process. Meas. Phenom. 2016. 34, No. 4. P.
042203. doi: 10.1116/1.4955152.
27. Wormington M., Panaccione C., Matney K.M. and
Bowen D.K. Characterization of structures from X-
ray scattering data using genetic algorithms. Philos.
Trans. R. Soc. A Math. Phys. Eng. Sci. 1999. 357, N
1761. P. 2827–2848. doi: 10.1098/rsta.1999.0469.
28. Storn R. and Price K. Differential evolution – a
simple and efficient heuristic for global
optimization over continuous spaces. J. Glob.
Optim. 1997. 11, No. 4. P. 341–359.
doi: 10.1023/A:1008202821328.
29. Liubchenko O.I., Kladko V.P., Sabov T.M. and
Dubikovskyi O.V. X-ray analysis for micro-
structure of AlN/GaN multiple quantum well
systems. J. Mater. Sci. Mater. Electron. 2019. 30,
No 1. P. 499–507. doi: 10.1007/s10854-018-0315-3.
30. Liubchenko O.I. and Kladko V.P. Simulation of
X-ray diffraction spectra for AlN/GaN multiple
quantum well structures on AlN(0001) with
interface roughness and variation of vertical layers
thickness. Metallofiz. i Noveishie Tekhnologii.
2018. 40, No. 6. P. 759–776.
doi: 10.15407/mfint.40.06.0759.
31. Boulle A. and Debelle A. Strain-profile
determination in ion-implanted single crystals using
generalized simulated annealing. J. Appl.
Crystallogr. 2010. 43, No. 5. P. 1046–1052. doi:
10.1107/S0021889810030281.
32. Zolotoyabko E. Extended kinematic approach to the
simulation of high-resolution X-ray diffraction
spectra. Application to structures with buried
amorphous layers. J. Appl. Crystallogr. 1998. 31,
No. 2. P. 241–251.
doi:10.1107/S0021889897009096.
33. Liubchenko O., Kladko V. and Gudymenko O. Yo.
Modeling of X-ray rocking curves for layers after
two-stage ion-implantation. Semicond. Physics,
Quantum Electron. Optoelectron. 2017. 20, No. 3.
P. 355–361. doi: 10.15407/spqeo20.03.355.
34. Kladko V.P., Datsenko L.I., Bak-Misiuk J.,
Olikhovskii S.I., Machulin V.F., Prokopenko I.V.,
Molodkin V.B. and Maksimenko Z.V. Calculation
of two-dimensional maps of diffuse scattering by a
real crystal with microdefects and comparison of
results obtained from three-crystal diffractometry. J.
Phys. D. Appl. Phys. 2001. 34, No. 10A. P. A87–
A92. doi: 10.1088/0022-3727/34/10A/318.
35. Shcherbachev K.D., Bublik V.T., Mordkovich V.N.
and Pazhin D.M. Specific features of formation of
radiation defects in the silicon layer in “silicon-on-
insulator” structures. Semiconductors. 2011. 45, No.
6. P. 738–742. doi: 10.1134/S1063782611060224.
36. Moram M.A., Sadler T.C., Häberlen M., Kappers
M.J. and Humphreys C.J. Dislocation movement in
GaN films. Appl. Phys. Lett. 2010. 97, No. 26. P.
261907. doi: 10.1063/1.3532965.
37. Iwata H., Kobayashi H., Kamiya T., Kamei R., Saka
H., Sawaki N., Irie M., Honda Y. and Amano H.
Annealing effect on threading dislocations in a GaN
grown on Si substrate. J. Cryst. Growth. 2017. 468.
P. 835–838. doi: 10.1016/j.jcrysgro.2017.01.001
38. Kyutt R.T. Defect structure of epitaxial layers of III
nitrides as determined by analyzing the shape of X-
ray diffraction peaks. Tech. Phys. 2017. 62, No. 4.
P. 598–603. doi: 10.1134/s1063784217040144
39. Kaganer V.M., Brandt O., Trampert A. and Ploog
K.H. X-ray diffraction peak profiles from threading
dislocations in GaN epitaxial films. Phys. Rev. B:
Condens. Matter Mater. Phys. 2005. 72, No. 4. P.
045423. doi: 10.1103/PhysRevB.72.045423.
40. Barchuk M., Holý V., Miljević B., Krause B.,
Baumbach T., Hertkorn J. and Scholz F. X-ray
diffuse scattering from threading dislocations in
epitaxial GaN layers. J. Appl. Phys. 2010. 108, No.
4. P. 043521. doi: 10.1063/1.3460803.
SPQEO, 2019. V. 22, N 1. P. 119-129.
Liubchenko O.I., Kladko V.P., Stanchu H.V. et al. The effect of ion implantation on structural damage …
129
Authors and CV
Oleksii I. Liubchenko, born in 1991,
graduated from the National
Technical University of Ukraine “Igor
Sikorsky Kyiv Polytechnic Institute”
in 2015 and postgraduate study at the
V. Lashkaryov Institute of Semicon-
ductor Physics. Since 2018, he is the
junior researcher at Department for
Diffraction Analysis of the Structure
of Semiconductors in V. Lashkaryov Institute of
Semiconductor Physics, NASU. The area of scientific
interests is material analysis sciences, high-resolution X-
ray diffraction and computer simulation of XRD spectra.
He authored 6 articles.
E-mail: lubchenco.a@gmail.com
Vasyl P. Kladko, Doctor of Sciences
(Physics and Mathematics), Corres-
ponding Member of the National
Academy of Sciences of Ukraine,
Head of the Department of Structural
and Elemental Analysis of Materials
and Systems at the V. Lashkaryov
Institute of Semiconductor Physics,
National Academy of Sciences of
Ukraine. Author of more than 300 publications. His
research interests include: solid-state physics, dynamical
theory of diffraction of radiation, X-ray optics, X-ray
diffraction analysis of semiconductor crystals, hetero- and
nanosystems.
H.V. Stanchu, born in 1987. Work
experience: junior researcher at the
V. Lashkaryov Institute of Semi-
conductor Physics, NAS of Ukraine.
PhD student at the University of
Arkansas. Authored over 18 peer-
reviewed articles. The area of his
scientific interests includes solid state
physics, crystal characterization, and materials science.
Tomash Sabov, born 1992 in
Uzhgorod (Ukraine), graduated in
electronics 2015 (Kyiv Polytechnic
Institute), since 2015 he is a Ph.D.
student at the V. Lashkaryov Institute
of Semiconductor Physics, NASU.
Since 2018 he is a junior researcher at
the Department of Ion Beam Engi-
neering at the V. Lashkaryov Institute
of Semiconductor Physics. He is author of more than 20
publications. His main research activity is physics of thin
films, chromogenic materials and SIMS analysis.
Victor P. Melnik, Doctor of Sciences
(Physics and Mathematics), Senior
Researcher, Department of Ion-Beam
Engineering, V. Lashkaryov Institute
of Semiconductor Physics, National
Academy of Sciences of Ukraine.
Author of more than 150 publications.
His research interests include: solid-
state physics, ion-beam material
synthesis, SIMS spectroscopy.
Serhii B. Kryvyi, born in 1991,
defended his PhD thesis in solid state
physics in 2017. Researcher at the
Department of Structural and
Elemental Analysis of Materials and
Systems, V. Lashkaryov Institute of
Semiconductor Physics, NAS of
Ukraine. Postdoctoral fellowship in
Laboratory of X-ray and Electron
Microscopy Research, Institute of Physics Polish
Academy of Sciences. Authored 14 articles and 1 patent.
The area of his scientific interests includes solid state
physics, real crystal structure, and materials science.
A.E. Belyaev, Director of V. Lashka-
ryov Institute of Semiconductor
Physics, Асаdemician of NAS of
Ukraine, Professor, Doctor of
Sciences. The area of his scientific
interests includes electrical and
galvanomagnetic properties of
semiconductors.
|
| id | nasplib_isofts_kiev_ua-123456789-215418 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1560-8034 |
| language | English |
| last_indexed | 2026-03-23T18:50:58Z |
| publishDate | 2019 |
| publisher | Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
| record_format | dspace |
| spelling | Liubchenko, O.I. Kladko, V.P. Stanchu, H.V. Sabov, T.M. Melnik, V.P. Kryvyi, S.B. Belyaev, A.Ye. 2026-03-16T10:57:54Z 2019 The effect of ion implantation on structural damage in compositionally graded AlGaN layers / O.I. Liubchenko, V.P. Kladko, H.V. Stanchu, T.M. Sabov, V.P. Melnik, S.B. Kryvyi, A.Ye. Belyaev // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2019. — Т. 22, № 1. — С. 119-129. — Бібліогр.: 40 назв. — англ. 1560-8034 PACS: 61.05.-a, 61.05.C-, 61.10.Nz, 61.72.-y, 68.55.Ln, 68.65.-k, 78.55.Cr, 78.70.Ck https://nasplib.isofts.kiev.ua/handle/123456789/215418 https://doi.org/10.15407/spqeo22.01.119 Compositionally graded AlₓGa₁₋ₓN alloys with the Al concentration in the (7 ≤ x ≤ 32) range were implanted with Ar+ ions to study the structural and strain changes (strain engineering). It was shown that ion implantation leads to ~0.3…0.46% hydrostatic strains and a relatively low damage of the crystal structure. The ion-implantation leads mainly to an increase in the density of point defects, while the dislocation configuration is almost unaffected. The density of microdefects is sufficiently reduced after the post implantation annealing. The structural quality of the AlₓGa₁₋ₓN layers strongly depends on the Al concentration and worsens with increasing Al. The implantation-induced structural changes in highly dislocated AlₓGa₁₋ₓN layers are generally less pronounced. Based on the X-ray diffraction, a model is developed to explain the strain field behavior in the AlₓGa₁₋ₓN/GaN heterostructures by migration of point defects and strain field redistribution. The approach to simulate 2θ/ω scans using statistical dynamical theory of X-ray diffraction for implanted compositionally graded structures, AlGaN, has been developed. en Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України Semiconductor Physics Quantum Electronics & Optoelectronics Sensors The effect of ion implantation on structural damage in compositionally graded AlGaN layers Article published earlier |
| spellingShingle | The effect of ion implantation on structural damage in compositionally graded AlGaN layers Liubchenko, O.I. Kladko, V.P. Stanchu, H.V. Sabov, T.M. Melnik, V.P. Kryvyi, S.B. Belyaev, A.Ye. Sensors |
| title | The effect of ion implantation on structural damage in compositionally graded AlGaN layers |
| title_full | The effect of ion implantation on structural damage in compositionally graded AlGaN layers |
| title_fullStr | The effect of ion implantation on structural damage in compositionally graded AlGaN layers |
| title_full_unstemmed | The effect of ion implantation on structural damage in compositionally graded AlGaN layers |
| title_short | The effect of ion implantation on structural damage in compositionally graded AlGaN layers |
| title_sort | effect of ion implantation on structural damage in compositionally graded algan layers |
| topic | Sensors |
| topic_facet | Sensors |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/215418 |
| work_keys_str_mv | AT liubchenkooi theeffectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT kladkovp theeffectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT stanchuhv theeffectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT sabovtm theeffectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT melnikvp theeffectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT kryvyisb theeffectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT belyaevaye theeffectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT liubchenkooi effectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT kladkovp effectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT stanchuhv effectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT sabovtm effectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT melnikvp effectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT kryvyisb effectofionimplantationonstructuraldamageincompositionallygradedalganlayers AT belyaevaye effectofionimplantationonstructuraldamageincompositionallygradedalganlayers |