NbN and Nb-Si-N films were deposited by magnetron sputtering the Nb and Si targets on silicon wafers at various bias voltage, Us. The films were investigated by an atomic force microscope (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nanoindentation. The deposited films were annealed to establish their thermal stability. The NbN films were nanostructured, and the Nb-Si-N films had a nanocomposite structure, and represented an aggregation of δ-NbNx nanocrystallites embedded into the amorphous Si3N4 tissue (nc-δ-NbNx/a-Si3N4)

Ivashchenko, V.I.

Kuzmenko, A.P.

Lytvyn, O.S.

Rogoz, V.M.

Scrynskyy, P.L.

Sobol, O.V.

English

SocioEconomic Challenges Journal (Sumy State University)

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  
NANOMATERIALS: APPLICATIONS AND PROPERTIES 
Vol. 3 No 1, 01NTF22(4pp) (2014) 
 
 
2304-1862/2014/3(1)01NTF22(4) 01NTF22-1  2014 Sumy State University 
Structure and Properties NbN and Nb-Si-N Deposited by Magnetron Sputtering 
 
V.I. Іvashchenko1, P.L. Scrynskyy1, O.S. Lytvyn2, V.M. Rogoz3,*, O.V. Sobol4, A.P. Kuzmenko5 
 
1 Institute for Problems of Material Science, NASU, 3, Кrzhyzhanovsky Str., 03680 Kiev - 142, Ukraine 
2 Institute of Semiconductor Physics, NASU, 41, Nauky Pr., 03028 Kyiv, Ukraine 
3 Sumy State University, 2, Rimsky-Korsakov Str., 40000 Sumy, Ukraine 
4 National Technical University "KPI", 21, Frunze Str. , 61002 Kharkov, Ukraine 
5 Kursk State Technical University, Center for collective use "High Tech", 94, October 50 Str.,  
305040 Kursk, Russia 
 
(Received 29 July 2014; published online 29 August 2014) 
 
NbN and Nb-Si-N films were deposited by magnetron sputtering the Nb and Si targets on silicon 
wafers at various bias voltage, Us. The films were investigated by an atomic force microscope (AFM), X-ray 
diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nanoindentation. The deposited films were 
annealed to establish their thermal stability. The NbN films were nanostructured, and the Nb-Si-N films 
had a nanocomposite structure, and represented an aggregation of δ-NbNx nanocrystallites embedded into 
the amorphous Si3N4 tissue (nc-δ-NbNx / a-Si3N4). 
 
Keywords: AFM, XRD, NbN, Nb-Si-N, XPS. 
 
 PACS numbers: 61.05.C –, 61.05.cp, 68.37.Ps, 61.05.js 
 
 
                                                          
*v.rogoz2009@gmail.com 
1. INTRODUCTION 
 
Nanostructured films are widely used for surface 
hardening of cutting tools due to high hardness, good 
corrosion stability and low friction coefficient [1-7]. 
Among these films, NbN-based films are of increasing 
interest. The hardness of such binary NbN nitride films 
is much more high than the bulk material 
(HV = 14 GPa) and higher than other binary nitride 
films (TiN, ZrN, VN). The hardness of the NbN films 
deposited by different arc deposition systems reaches 34-
49 GPa [8]. The NbN films were also prepared by using 
magnetron sputtering (MS) [9], ion beam assisted depo-
sition [10], pulsed laser deposition [11]. An increase in 
hardness was reached by the formation of the nanocom-
posite or nanolayered structures of the films based on 
niobium nitride. Silicon nitrides are known for their high 
temperature stability, low friction coefficient and high 
oxidation resistance. Hence, one can expect that that 
Nb-Si-N nanocomposite and multilayers will combine 
the properties of the constituent materials and will have 
improved properties as compared to NbN. In further, we 
will put an accent on the films prepared with magnetron 
sputtering. We reviewed the recent investigations on 
NbN and Nb-Si-N films deposited by magnetron sputter-
ing. 
We see from this brief review that, despite the previ-
ous investigations of the NbN and Nb-Si-N films, the 
comparative study of these two kinds of films prepared 
at the same deposition parameters was not yet carried 
out. Also, so far, the effect of the bias voltage supplied to 
the substrate (Us) on film properties was not analyzed. 
Besides, we note that, up to date, any theoretical inves-
tigations of the NbN/SiNx nanostructures at the atomic 
level were not carried out.  
In this work we aimed to fill these gaps in the inves-
tigations of NbN and Nb-Si-N films. These films were 
deposited on silicon wafers at various Us. The films were 
then investigated by: an atomic force microscope (AFM), 
X-ray diffraction (XRD), X-ray photoelectron spectrosco-
py (XPS), nanoindentaion and microindentation. The 
deposited nanocomposite films were annealed to estab-
lish their thermal stability. The NbN(001)/Si3N4 hetero-
structures were calculated at various temperature using 
first-principles molecular dynamics simulations to inter-
pret the experimental results on the Nb-Si-N films. 
 
2. EXPERIMENTAL AND COMPUTATIONAL 
DETAILS 
 
The NbN-based films were deposited on the mirror-
polished Si (100) wafer by DC magnetron sputtering 
the Nb (99.9 %, Ø72 4 mm) and Si (99.999 %, Ø72 4 
mm) targets in an argon-nitrogen atmosphere at the 
following deposition parameters: substrate tempera-
ture TS= 3500 С; substrate bias Us = 0 V, -20 V -40 V, -
70 V; flow rate (F) FAr = 40 sccm; FN2 = 13 sccm; work-
ing pressure PC = 0.17 Pa. The current applied to the 
Nb target was 150, 200, 250 and 300 mA, which corre-
sponded to a discharge power density PNb = 17.1 W/cm2, 
respectively. The current on the Si target was 100 mA 
(PSi = 5.3 W/cm2). The base pressure of the vacuum 
chamber was better than 10-4 Pa. The distance between 
the targets and the substrate holder was 8 cm. The 
dihedral angle between the target planes was ~ 450. 
The substrates were cleaned ultrasonically before they 
were put into the vacuum chamber. Also, before deposi-
tion, the substrates were etched in the vacuum cham-
ber in hydrogen plasma during 5 min. The film depos-
ited at PNb = 14.3 W/cm2 was annealed in a vacuum 
(0.001 Pa) during 2 ours at 600, 800 and 1000 C. 
The crystal structure of the films was determined 
by X-ray diffraction (XRD, diffractometer DRON-3M) 
using CuK  radiation. The crystallite size in films was 
evaluated from the broadening of peaks in X-ray dif-
fraction spectra using Scherrer formula. The chemical 
 V.I. ІVASHCHENKO, P.L. SCRYNSKYY, ET.AL. PROC. NAP 3, 01NTF22 (2014) 
 
 
01NTF22-2 
bonding status of films was observed by X-ray photoe-
lectron spectroscopy (XPS, EC 2401, USSR) using 
MgK  radiation (E=1253.6 eV). The Au 4f7/2 and Cu 
2p3/2 peaks with binding energy at 84.0  0.05 eV and 
932.66 0.05 eV, respectively, were used as a reference. 
Surface morphology was analyzed by atomic force mi-
croscope (AFM) NanoScope IIIa Dimension 3000 (Digi-
tal Instruments, USA). The hardness and elastic modu-
lus of films were determined from indentation by 
Nanoindenter-G200 instrument equipped with a 
Berkovich pyramidal tip under load in the range of 9 -
 13 mN. This range of loads was chosen in order to ob-
tain prominent plastic deformation of film while avoid-
ing the influence of substrate material. The nanohard-
ness (H) and elastic modulus (E) data was obtained 
from the load-displacement curves using Oliver and 
Pharr method. The Knoop hardness (HK) was estimat-
ed by a Microhardness Tester Micromet 2103 BUEH-
LER LTD at loading of 100 mN. 
 
3. RESULTS AND DISCUSSION 
 
Figure 1 shows the AFM surface topography of the 
NbN and Nb-Si-N films deposited at various Us. One 
can see that the film surface roughness increases with 
Us. Also, the surface roughness in Nb-Si-N films is 
smaller than in NbN films, which can be due to the 
availability the amorphous SiNx tissue in Nb-Si-N films 
(see below). It follows that a decrease in the bias volt-
age Us and an introduction of silicon promote the re-
duction of surface roughness. 
 
 
 
Fig. 1 – AFM images of: the NbN films deposited at Us = 0 V 
(RMS = 5.3 nm) (а) and Us = -70 V (RMS = 2.9 nm) (b); Nb-Si-
N films deposited at Us = 0 V (RMS = 2.0 nm) (с) и Us = -70 V 
(RMS = 0.7 nm) (d) 
 
The XRD spectra of the deposited NbN and Nb-Si-N 
films are shown in Fig. 2 and Fig. 3. The peak A at 35.1 -
 35.40 and the peak B at 41.1 - 41.40 can be assigned to 
the δ-NbNx(111) and δ-NbNx(200) reflections, respectively. 
The grain size estimated from the Scherrer formula was 
in the ranges 4.1 − 8.7 nm and 18.1 - 19.8 nm for the NbN 
and Nb-Si-N films, respectively. It follows that an intro-
duction of Si leads to an increase of the NbN grains. 
20 30 40 50 60 70 80 90 100
50
100
150
200
250
300
-N
b
N
(4
0
0
)
-N
b
N
(2
2
2
)
-N
b
N
(3
1
1
)
-N
b
N
(1
2
 6
6
)
-N
b
N
(2
2
0
)
-N
b
N
(2
0
0
)
-N
b
N
(1
1
1
)
-N
b
N
(5
3
2
)
I,
 a
rb
. 
u
n
.
degr
 
 
1
2
3
 
 
Fig. 2 – XRD spectra of NbN films at 1. Us = 0 V, 
2. Us = − 40 V, 3. Us= - 70 V 
 
20 30 40 50 60 70 80 90 100
0
50
100
150
200
-N
b
N
(4
0
0
)
-N
b
N
(2
2
2
)
-N
b
N
(3
1
1
)
-N
b
N
(2
2
0
)
S
i 3
N
4
(3
0
2
)
-N
b
N
(2
0
0
)
-N
b
N
(1
1
1
)
S
i 3
N
4
(3
0
1
)
 
 
I,
 a
rb
. 
u
n
.
degr
1
2
3
4
 
 
Fig. 3 – XRD spectra of Nb-Si-N films at 1. Us = 0 V, 2. Us = -
 20 V, 3. Us = - 40 V, 4.Us= - 70 V 
 
The results of the XPS examination of the as depos-
ited and annealed NbN and Nb-Si-N films are present-
ed in Fig. 4. It is known that a native oxide grows on 
Nb compounds when exposed to air [12], and the peaks 
at 204.07 eV and 206.88 eV can be assigned to Nb 3d in 
NbN (203.97 eV [13]) and Nb2N2-xO3+x (207.0 eV [14]). 
For NbN films, the peak at 397.4 eV in the N 1s spec-
trum is determined by Nb-N bonds, whereas for Nb-Si-
N films, this peak is located around 397.2 eV, and can 
be assigned to N 1s in NbN (397.4 eV [12]). 
We suppose that the asymmetry of the N 1s peak 
can be caused by the Si-N bonds in Si3N4 (397.8 eV 
[14]). XPS measurements of the Si 2p spectrum provide 
further information on the Si bonding in the Nb-Si-N 
films (cf. Fig. 4). The peak at a binding energy of 
101.7 eV is assigned to Si in Si3N4 (101.7 eV [14]), and 
a shoulder at 103.3 eV in the Si 2p spectrum of the an-
nealed films is supposed to be due to the Si-O bonds in 
SiO2 (103.5 eV [14]). Finally, the O 1s spectra of the 
NbN and Nb-Si-N films are centered around 530.5 eV 
and 530.9 eV, respectively, and can be attributed to the 
Nb-O bonds in Nb2O5 (530.4 eV) and Nb2O2 (530.7 eV 
[14]), respectively. In the case of Nb-Si-N films, the Si-
 STRUCTURE AND PROPERTIES NBN AND NB-SI-N … PROC. NAP 3, 01NTF22 (2014) 
 
 
01NTF22-3 
O bonds in SiO2 can form the wide tail around 532.9 eV 
[14] (cf. Fig. 4). Using the XPS data (cf. Fig. 4), we es-
timated the niobium, nitrogen and silicon contents 
(CNb, CN and CSi, respectively) in NbN and Nb-Si-N 
films. It was found that CNb = 44.5 at.%, CN = 55.5 at.% 
for NbN films and and CNb = 45.1 at.%, CN = 43.2 at.% 
and CSi = 1.7 at.% for Nb-Si-N films.  
 
 
 
Fig. 4 – XPS spectra of the core levels in NbN (solid line), Nb-
Si-N (dashed line) and annealed at 10000C Nb-Si-N (dotted 
line) films deposited at Pw=14.3 W/cm2. The vertical lines 
denote the binding energies of the XPS peaks of: Nb 3d in 
NbN, 203.97 eV [13] and Nb2N2-xO3+x, 207.0 eV [14]; N 1s in 
NbN, 397.4 eV [12] and Si3N4, 397.8 eV [14]; Si 2p in Si3N4, 
101.7 eV and SiO2, 103.5 eV [14]; O 1s in Nb2O5, 530.4 eV,  
Nb2O2, 530.7 eV and SiO2, 532.9 [14] 
 
Comparison of the results presented in Fig. 1-4 en-
ables us to establish the structure of the NbN and Nb-
Si-N films. The NbN films are nanostructured, and the 
Nb-Si-N films have a nanocomposite structure, and 
represent an aggregation of δ-NbNx nanocrystallites 
embedded into the amorphous Si3N4 tissue (nc-δ-
NbNx/a-Si3N4). In contrast to NbN films, Nb-Si-N films 
are textured with the preferable (200) grain orienta-
tion. The films contain oxygen in the view of niobium 
oxides. For Nb-Si-N films, we also suppose that, oxygen 
forms SiO2 that is segregated along grain boundaries. 
We note that, despite the larger grain sizes, the surface 
roughness of the Nb-Si-N films is smaller as compared 
to that of the NbN films. One can assume that the 
amorphous SiN4 tissue in nanocomposite Nb-Si-N films 
smears the relief of the film surface, for this reason, the 
surface roughness of the nanocomposite films should be 
lower than that of NbN films. 
The dependence of nanohardness (H) and elastic 
modulus (E) on indenter penetration (L) of the deposit-
ed films are presented in Fig. 5 and Fig. 6. It is seen 
that, beginning with 75 nm, the nanohardness practi-
cally does not depend on L. The elastic modulus de-
creases upon a reaching maximum values at 
L = 50 nm.  These results point out that the soft silicon 
substrate does not exert influence on the nanohardness 
of the films. The elastic modulus of the films turns out 
to be more sensitive to the substrates, especially at 
high L.  
 
 
 
Fig. 5 – Dependences of the nanohardness (H) and elastic 
modulus (E) on nanoindenter penetration (L) for the 
NbN films deposited at various bias voltage 
 
 
 
Fig. 6 – Dependences of the nanohardness (H) and elastic 
modulus (E) on nanoindenter penetration (L) for the Nb−Si−N 
films deposited at various bias voltage 
 
4. CONCLUSIONS 
 
The NiCoCrAlY coating on the flat specimens of 
nickel base superalloy JS6U were produced by a multi-
chamber detonation sprayer. The MCDS application 
allows to form a dense hard layer with porosity below 
1 %. Results of this work open up new prospects for 
further elaboration of new technologies to making 
protective NiCoCrAlY coatings which can enhance 
properties of nickel base superalloy. 
 
 V.I. ІVASHCHENKO, P.L. SCRYNSKYY, ET.AL. PROC. NAP 3, 01NTF22 (2014) 
 
 
01NTF22-4 
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Structure and Properties NbN and Nb-Si-N Deposited by Magnetron Sputtering

Electronic Sumy State University Institutional Repository

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE  NANOMATERIALS: APPLICATIONS AND PROPERTIES Vol. 3 No 1, 01NTF22(4pp) (2014)   2304-1862/2014/3(1)01NTF22(4) 01NTF22-1  2014 Sumy State University Structure and Properties NbN and Nb-Si-N Deposited by Magnetron Sputtering  V.I. Іvashchenko1, P.L. Scrynskyy1, O.S. Lytvyn2, V.M. Rogoz3,*, O.V. Sobol4, A.P. Kuzmenko5  1 Institute for Problems of Material Science, NASU, 3, Кrzhyzhanovsky Str., 03680 Kiev - 142, Ukraine 2 Institute of Semiconductor Physics, NASU, 41, Nauky Pr., 03028 Kyiv, Ukraine 3 Sumy State University, 2, Rimsky-Korsakov Str., 40000 Sumy, Ukraine 4 National Technical University "KPI", 21, Frunze Str. , 61002 Kharkov, Ukraine 5 Kursk State Technical University, Center for collective use "High Tech", 94, October 50 Str.,  305040 Kursk, Russia  (Received 29 July 2014; published online 29 August 2014)  NbN and Nb-Si-N films were deposited by magnetron sputtering the Nb and Si targets on silicon wafers at various bias voltage, Us. The films were investigated by an atomic force microscope (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nanoindentation. The deposited films were annealed to establish their thermal stability. The NbN films were nanostructured, and the Nb-Si-N films had a nanocomposite structure, and represented an aggregation of δ-NbNx nanocrystallites embedded into the amorphous Si3N4 tissue (nc-δ-NbNx / a-Si3N4).  Keywords: AFM, XRD, NbN, Nb-Si-N, XPS.   PACS numbers: 61.05.C –, 61.05.cp, 68.37.Ps, 61.05.js                                                             *v.rogoz2009@gmail.com 1. INTRODUCTION  Nanostructured films are widely used for surface hardening of cutting tools due to high hardness, good corrosion stability and low friction coefficient [1-7]. Among these films, NbN-based films are of increasing interest. The hardness of such binary NbN nitride films is much more high than the bulk material (HV = 14 GPa) and higher than other binary nitride films (TiN, ZrN, VN). The hardness of the NbN films deposited by different arc deposition systems reaches 34-49 GPa [8]. The NbN films were also prepared by using magnetron sputtering (MS) [9], ion beam assisted depo-sition [10], pulsed laser deposition [11]. An increase in hardness was reached by the formation of the nanocom-posite or nanolayered structures of the films based on niobium nitride. Silicon nitrides are known for their high temperature stability, low friction coefficient and high oxidation resistance. Hence, one can expect that that Nb-Si-N nanocomposite and multilayers will combine the properties of the constituent materials and will have improved properties as compared to NbN. In further, we will put an accent on the films prepared with magnetron sputtering. We reviewed the recent investigations on NbN and Nb-Si-N films deposited by magnetron sputter-ing. We see from this brief review that, despite the previ-ous investigations of the NbN and Nb-Si-N films, the comparative study of these two kinds of films prepared at the same deposition parameters was not yet carried out. Also, so far, the effect of the bias voltage supplied to the substrate (Us) on film properties was not analyzed. Besides, we note that, up to date, any theoretical inves-tigations of the NbN/SiNx nanostructures at the atomic level were not carried out.  In this work we aimed to fill these gaps in the inves-tigations of NbN and Nb-Si-N films. These films were deposited on silicon wafers at various Us. The films were then investigated by: an atomic force microscope (AFM), X-ray diffraction (XRD), X-ray photoelectron spectrosco-py (XPS), nanoindentaion and microindentation. The deposited nanocomposite films were annealed to estab-lish their thermal stability. The NbN(001)/Si3N4 hetero-structures were calculated at various temperature using first-principles molecular dynamics simulations to inter-pret the experimental results on the Nb-Si-N films.  2. EXPERIMENTAL AND COMPUTATIONAL DETAILS  The NbN-based films were deposited on the mirror-polished Si (100) wafer by DC magnetron sputtering the Nb (99.9 %, Ø72 4 mm) and Si (99.999 %, Ø72 4 mm) targets in an argon-nitrogen atmosphere at the following deposition parameters: substrate tempera-ture TS= 3500 С; substrate bias Us = 0 V, -20 V -40 V, -70 V; flow rate (F) FAr = 40 sccm; FN2 = 13 sccm; work-ing pressure PC = 0.17 Pa. The current applied to the Nb target was 150, 200, 250 and 300 mA, which corre-sponded to a discharge power density PNb = 17.1 W/cm2, respectively. The current on the Si target was 100 mA (PSi = 5.3 W/cm2). The base pressure of the vacuum chamber was better than 10-4 Pa. The distance between the targets and the substrate holder was 8 cm. The dihedral angle between the target planes was ~ 450. The substrates were cleaned ultrasonically before they were put into the vacuum chamber. Also, before deposi-tion, the substrates were etched in the vacuum cham-ber in hydrogen plasma during 5 min. The film depos-ited at PNb = 14.3 W/cm2 was annealed in a vacuum (0.001 Pa) during 2 ours at 600, 800 and 1000 C. The crystal structure of the films was determined by X-ray diffraction (XRD, diffractometer DRON-3M) using CuK  radiation. The crystallite size in films was evaluated from the broadening of peaks in X-ray dif-fraction spectra using Scherrer formula. The chemical  V.I. ІVASHCHENKO, P.L. SCRYNSKYY, ET.AL. PROC. NAP 3, 01NTF22 (2014)   01NTF22-2 bonding status of films was observed by X-ray photoe-lectron spectroscopy (XPS, EC 2401, USSR) using MgK  radiation (E=1253.6 eV). The Au 4f7/2 and Cu 2p3/2 peaks with binding energy at 84.0  0.05 eV and 932.66 0.05 eV, respectively, were used as a reference. Surface morphology was analyzed by atomic force mi-croscope (AFM) NanoScope IIIa Dimension 3000 (Digi-tal Instruments, USA). The hardness and elastic modu-lus of films were determined from indentation by Nanoindenter-G200 instrument equipped with a Berkovich pyramidal tip under load in the range of 9 - 13 mN. This range of loads was chosen in order to ob-tain prominent plastic deformation of film while avoid-ing the influence of substrate material. The nanohard-ness (H) and elastic modulus (E) data was obtained from the load-displacement curves using Oliver and Pharr method. The Knoop hardness (HK) was estimat-ed by a Microhardness Tester Micromet 2103 BUEH-LER LTD at loading of 100 mN.  3. RESULTS AND DISCUSSION  Figure 1 shows the AFM surface topography of the NbN and Nb-Si-N films deposited at various Us. One can see that the film surface roughness increases with Us. Also, the surface roughness in Nb-Si-N films is smaller than in NbN films, which can be due to the availability the amorphous SiNx tissue in Nb-Si-N films (see below). It follows that a decrease in the bias volt-age Us and an introduction of silicon promote the re-duction of surface roughness.    Fig. 1 – AFM images of: the NbN films deposited at Us = 0 V (RMS = 5.3 nm) (а) and Us = -70 V (RMS = 2.9 nm) (b); Nb-Si-N films deposited at Us = 0 V (RMS = 2.0 nm) (с) и Us = -70 V (RMS = 0.7 nm) (d)  The XRD spectra of the deposited NbN and Nb-Si-N films are shown in Fig. 2 and Fig. 3. The peak A at 35.1 - 35.40 and the peak B at 41.1 - 41.40 can be assigned to the δ-NbNx(111) and δ-NbNx(200) reflections, respectively. The grain size estimated from the Scherrer formula was in the ranges 4.1 − 8.7 nm and 18.1 - 19.8 nm for the NbN and Nb-Si-N films, respectively. It follows that an intro-duction of Si leads to an increase of the NbN grains. 20 30 40 50 60 70 80 90 10050100150200250300-NbN(400)-NbN(222)-NbN(311)-NbN(12 66)-NbN(220)-NbN(200)-NbN(111)-NbN(532)I, arb. un.degr  123  Fig. 2 – XRD spectra of NbN films at 1. Us = 0 V, 2. Us = − 40 V, 3. Us= - 70 V  20 30 40 50 60 70 80 90 100050100150200-NbN(400)-NbN(222)-NbN(311)-NbN(220)Si 3N4(302)-NbN(200)-NbN(111)Si 3N4(301)  I, arb. un.degr1234  Fig. 3 – XRD spectra of Nb-Si-N films at 1. Us = 0 V, 2. Us = - 20 V, 3. Us = - 40 V, 4.Us= - 70 V  The results of the XPS examination of the as depos-ited and annealed NbN and Nb-Si-N films are present-ed in Fig. 4. It is known that a native oxide grows on Nb compounds when exposed to air [12], and the peaks at 204.07 eV and 206.88 eV can be assigned to Nb 3d in NbN (203.97 eV [13]) and Nb2N2-xO3+x (207.0 eV [14]). For NbN films, the peak at 397.4 eV in the N 1s spec-trum is determined by Nb-N bonds, whereas for Nb-Si-N films, this peak is located around 397.2 eV, and can be assigned to N 1s in NbN (397.4 eV [12]). We suppose that the asymmetry of the N 1s peak can be caused by the Si-N bonds in Si3N4 (397.8 eV [14]). XPS measurements of the Si 2p spectrum provide further information on the Si bonding in the Nb-Si-N films (cf. Fig. 4). The peak at a binding energy of 101.7 eV is assigned to Si in Si3N4 (101.7 eV [14]), and a shoulder at 103.3 eV in the Si 2p spectrum of the an-nealed films is supposed to be due to the Si-O bonds in SiO2 (103.5 eV [14]). Finally, the O 1s spectra of the NbN and Nb-Si-N films are centered around 530.5 eV and 530.9 eV, respectively, and can be attributed to the Nb-O bonds in Nb2O5 (530.4 eV) and Nb2O2 (530.7 eV [14]), respectively. In the case of Nb-Si-N films, the Si- STRUCTURE AND PROPERTIES NBN AND NB-SI-N … PROC. NAP 3, 01NTF22 (2014)   01NTF22-3 O bonds in SiO2 can form the wide tail around 532.9 eV [14] (cf. Fig. 4). Using the XPS data (cf. Fig. 4), we es-timated the niobium, nitrogen and silicon contents (CNb, CN and CSi, respectively) in NbN and Nb-Si-N films. It was found that CNb = 44.5 at.%, CN = 55.5 at.% for NbN films and and CNb = 45.1 at.%, CN = 43.2 at.% and CSi = 1.7 at.% for Nb-Si-N films.     Fig. 4 – XPS spectra of the core levels in NbN (solid line), Nb-Si-N (dashed line) and annealed at 10000C Nb-Si-N (dotted line) films deposited at Pw=14.3 W/cm2. The vertical lines denote the binding energies of the XPS peaks of: Nb 3d in NbN, 203.97 eV [13] and Nb2N2-xO3+x, 207.0 eV [14]; N 1s in NbN, 397.4 eV [12] and Si3N4, 397.8 eV [14]; Si 2p in Si3N4, 101.7 eV and SiO2, 103.5 eV [14]; O 1s in Nb2O5, 530.4 eV,  Nb2O2, 530.7 eV and SiO2, 532.9 [14]  Comparison of the results presented in Fig. 1-4 en-ables us to establish the structure of the NbN and Nb-Si-N films. The NbN films are nanostructured, and the Nb-Si-N films have a nanocomposite structure, and represent an aggregation of δ-NbNx nanocrystallites embedded into the amorphous Si3N4 tissue (nc-δ-NbNx/a-Si3N4). In contrast to NbN films, Nb-Si-N films are textured with the preferable (200) grain orienta-tion. The films contain oxygen in the view of niobium oxides. For Nb-Si-N films, we also suppose that, oxygen forms SiO2 that is segregated along grain boundaries. We note that, despite the larger grain sizes, the surface roughness of the Nb-Si-N films is smaller as compared to that of the NbN films. One can assume that the amorphous SiN4 tissue in nanocomposite Nb-Si-N films smears the relief of the film surface, for this reason, the surface roughness of the nanocomposite films should be lower than that of NbN films. The dependence of nanohardness (H) and elastic modulus (E) on indenter penetration (L) of the deposit-ed films are presented in Fig. 5 and Fig. 6. It is seen that, beginning with 75 nm, the nanohardness practi-cally does not depend on L. The elastic modulus de-creases upon a reaching maximum values at L = 50 nm.  These results point out that the soft silicon substrate does not exert influence on the nanohardness of the films. The elastic modulus of the films turns out to be more sensitive to the substrates, especially at high L.     Fig. 5 – Dependences of the nanohardness (H) and elastic modulus (E) on nanoindenter penetration (L) for the NbN films deposited at various bias voltage    Fig. 6 – Dependences of the nanohardness (H) and elastic modulus (E) on nanoindenter penetration (L) for the Nb−Si−N films deposited at various bias voltage  4. CONCLUSIONS  The NiCoCrAlY coating on the flat specimens of nickel base superalloy JS6U were produced by a multi-chamber detonation sprayer. The MCDS application allows to form a dense hard layer with porosity below 1 %. Results of this work open up new prospects for further elaboration of new technologies to making protective NiCoCrAlY coatings which can enhance properties of nickel base superalloy.   V.I. ІVASHCHENKO, P.L. SCRYNSKYY, ET.AL. PROC. NAP 3, 01NTF22 (2014)   01NTF22-4 REFERENCES  1. A.D. Pogrebnjak, A.G. Ponomarev, A.P. Shpak, Phys. Usp. 55, 270 (2012).  2. A.D. Pogrebnjak, V.M. Beresnev, Nanocoatings, Nanosys-tems, Nanotechnologies (Bentham Sci. Pub.: Sharjah: 2012). 3. A.D. Pogrebnjak, V.M. Beresnev, A.A. Demianenko, Phys. Solid State 54, 1882 (2012).  4. R. Krause-Rehberg, A.D. Pogrebnyak, O.V. Sobol', Phys. Metals and Metallogr. 114 No8, 672 (2013).  5. A.D. Pogrebnjak, Yu.A. Kravchenko, S.B. Kislitsyn, Surf. Coat. Tech. 201 No6, 2621 (2006). 6. A.D. Pogrebnjak, S. Bratushka, V.I. Boyko, Nucl. Instr. & Meth. 145 No3, 373 (1998). 7. A.D. Pogrebnjak, A.D. Mikhaliov, N.A. Pogrebnjak, Phys. Lett. 241, 357 (1998). 8. V.N. Zhytomirsky, Surf. Coat. Technol. 201, 6122 (2007).  9. G.A. Fontalvo, V. Terziyska, C. Mitterer, Surf. Coat. Technol. 202, 1017 (2007).  10. N. Hayashi, I.H. Murzin, I. Sakamoto, M. Ohkubo Thin Solid Films 259, 146 (1995).  11. G. Cappuccio, U. Gambardella, A. Morone, S. Orlando, G.P. Patisi, Appl. Surf. Sci. 109, 399 (1997).  12. J. Wang, Z. Song, K. Xu, Surf. Coat. Technol. 201, 4931 (2007).  13. J.J. Jeong, C.M. Lee, Appl. Surf. Sci. 214, 11 (2003).  14. G. Beamson, D. Briggs, High Resolution XPS of Organic Polymers, The Scienta ESCA300 Database (Wiley Inter-science: 1992).  

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Structure and Properties NbN and Nb-Si-N Deposited by Magnetron Sputtering

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