Characteristics of the plasma created by ECR plasma source for thin films deposition
The construction of planar ECR plasma source with multipolar magnetic field is described and the distribution of plasma parameters is measured. Plasma density and electron temperature at the distance 2,5 cm from the magnet surface achieve 5×10¹⁰ сm⁻³ and 22,5 eV accordingly and they linearly decreas...
Saved in:
| Published in: | Вопросы атомной науки и техники |
|---|---|
| Date: | 2005 |
| Main Authors: | , , , , |
| Format: | Article |
| Language: | English |
| Published: |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2005
|
| Subjects: | |
| Online Access: | https://nasplib.isofts.kiev.ua/handle/123456789/79155 |
| 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: | Characteristics of the plasma created by ECR plasma source for thin films deposition / V.D. Fedorchenko, O.V. Byrka, V.V. Chebotarev, I.E. Garkusha, V.I. Tereshin // Вопросы атомной науки и техники. — 2005. — № 1. — С. 192-194. — Бібліогр.: 12 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
nasplib_isofts_kiev_ua-123456789-79155 |
|---|---|
| record_format |
dspace |
| spelling |
Fedorchenko, V.D. Byrka, O.V. Chebotarev, V.V. Garkusha, I.E. Tereshin, V.I. 2015-03-26T18:21:36Z 2015-03-26T18:21:36Z 2005 Characteristics of the plasma created by ECR plasma source for thin films deposition / V.D. Fedorchenko, O.V. Byrka, V.V. Chebotarev, I.E. Garkusha, V.I. Tereshin // Вопросы атомной науки и техники. — 2005. — № 1. — С. 192-194. — Бібліогр.: 12 назв. — англ. 1562-6016 PACS: 52.50.Dg; 81.15.Jj https://nasplib.isofts.kiev.ua/handle/123456789/79155 The construction of planar ECR plasma source with multipolar magnetic field is described and the distribution of plasma parameters is measured. Plasma density and electron temperature at the distance 2,5 cm from the magnet surface achieve 5×10¹⁰ сm⁻³ and 22,5 eV accordingly and they linearly decreased with the moving off from ECR zone. The possibility of homogeneous and dense films deposition for both pure metals and alloys is shown. В роботі розглянута конструкція планарного ЕЦР плазмового джерела з мультипольним магнітним полем та виміряно розподіл параметрів створюваної плазми. На відстані 2,5 см від поверхні магнітів густина плазми та електронна температура 5 *10¹⁰ см⁻³ та 22,5 еВ відповідно, які лінійно зменшуються при віддаленні від ЕЦР зони. Показана можливість нанесення однорідних та щільних плівок, як чистих металів, так і сплавів. В работе описана конструкция планарного ЭЦР плазменного источника с мультипольным магнитным полем и измерены распределения параметров создаваемой плазмы. На расстоянии 2,5 см от поверхности магнитов плотность плазмы и электронная температура 5*10¹⁰ см⁻³ и 22,5 еВ соответственно, которые линейно спадают при удалении от ЭЦР зоны. Показана возможность напыления однородных и плотных пленок, как чистых металлов, так и сплавов. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Low temperature plasma and plasma technologies Characteristics of the plasma created by ECR plasma source for thin films deposition Характеристики плазми створеної ЕЦР плазмовим джерелом для нанесення тонких плівок Харктеристики плазмы, созданной ЭЦР плазменным источником для нанесения тонких пленок Article published earlier |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
Characteristics of the plasma created by ECR plasma source for thin films deposition |
| spellingShingle |
Characteristics of the plasma created by ECR plasma source for thin films deposition Fedorchenko, V.D. Byrka, O.V. Chebotarev, V.V. Garkusha, I.E. Tereshin, V.I. Low temperature plasma and plasma technologies |
| title_short |
Characteristics of the plasma created by ECR plasma source for thin films deposition |
| title_full |
Characteristics of the plasma created by ECR plasma source for thin films deposition |
| title_fullStr |
Characteristics of the plasma created by ECR plasma source for thin films deposition |
| title_full_unstemmed |
Characteristics of the plasma created by ECR plasma source for thin films deposition |
| title_sort |
characteristics of the plasma created by ecr plasma source for thin films deposition |
| author |
Fedorchenko, V.D. Byrka, O.V. Chebotarev, V.V. Garkusha, I.E. Tereshin, V.I. |
| author_facet |
Fedorchenko, V.D. Byrka, O.V. Chebotarev, V.V. Garkusha, I.E. Tereshin, V.I. |
| topic |
Low temperature plasma and plasma technologies |
| topic_facet |
Low temperature plasma and plasma technologies |
| publishDate |
2005 |
| language |
English |
| container_title |
Вопросы атомной науки и техники |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| format |
Article |
| title_alt |
Характеристики плазми створеної ЕЦР плазмовим джерелом для нанесення тонких плівок Харктеристики плазмы, созданной ЭЦР плазменным источником для нанесения тонких пленок |
| description |
The construction of planar ECR plasma source with multipolar magnetic field is described and the distribution of plasma parameters is measured. Plasma density and electron temperature at the distance 2,5 cm from the magnet surface achieve 5×10¹⁰ сm⁻³ and 22,5 eV accordingly and they linearly decreased with the moving off from ECR zone. The possibility of homogeneous and dense films deposition for both pure metals and alloys is shown.
В роботі розглянута конструкція планарного ЕЦР плазмового джерела з мультипольним магнітним полем та виміряно розподіл параметрів створюваної плазми. На відстані 2,5 см від поверхні магнітів густина плазми та електронна температура 5 *10¹⁰ см⁻³ та 22,5 еВ відповідно, які лінійно зменшуються при віддаленні від ЕЦР зони. Показана можливість нанесення однорідних та щільних плівок, як чистих металів, так і сплавів.
В работе описана конструкция планарного ЭЦР плазменного источника с мультипольным магнитным полем и измерены распределения параметров создаваемой плазмы. На расстоянии 2,5 см от поверхности магнитов плотность плазмы и электронная температура 5*10¹⁰ см⁻³ и 22,5 еВ соответственно, которые линейно спадают при удалении от ЭЦР зоны. Показана возможность напыления однородных и плотных пленок, как чистых металлов, так и сплавов.
|
| issn |
1562-6016 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/79155 |
| citation_txt |
Characteristics of the plasma created by ECR plasma source for thin films deposition / V.D. Fedorchenko, O.V. Byrka, V.V. Chebotarev, I.E. Garkusha, V.I. Tereshin // Вопросы атомной науки и техники. — 2005. — № 1. — С. 192-194. — Бібліогр.: 12 назв. — англ. |
| work_keys_str_mv |
AT fedorchenkovd characteristicsoftheplasmacreatedbyecrplasmasourceforthinfilmsdeposition AT byrkaov characteristicsoftheplasmacreatedbyecrplasmasourceforthinfilmsdeposition AT chebotarevvv characteristicsoftheplasmacreatedbyecrplasmasourceforthinfilmsdeposition AT garkushaie characteristicsoftheplasmacreatedbyecrplasmasourceforthinfilmsdeposition AT tereshinvi characteristicsoftheplasmacreatedbyecrplasmasourceforthinfilmsdeposition AT fedorchenkovd harakteristikiplazmistvorenoíecrplazmovimdžerelomdlânanesennâtonkihplívok AT byrkaov harakteristikiplazmistvorenoíecrplazmovimdžerelomdlânanesennâtonkihplívok AT chebotarevvv harakteristikiplazmistvorenoíecrplazmovimdžerelomdlânanesennâtonkihplívok AT garkushaie harakteristikiplazmistvorenoíecrplazmovimdžerelomdlânanesennâtonkihplívok AT tereshinvi harakteristikiplazmistvorenoíecrplazmovimdžerelomdlânanesennâtonkihplívok AT fedorchenkovd harkteristikiplazmysozdannoiécrplazmennymistočnikomdlânaneseniâtonkihplenok AT byrkaov harkteristikiplazmysozdannoiécrplazmennymistočnikomdlânaneseniâtonkihplenok AT chebotarevvv harkteristikiplazmysozdannoiécrplazmennymistočnikomdlânaneseniâtonkihplenok AT garkushaie harkteristikiplazmysozdannoiécrplazmennymistočnikomdlânaneseniâtonkihplenok AT tereshinvi harkteristikiplazmysozdannoiécrplazmennymistočnikomdlânaneseniâtonkihplenok |
| first_indexed |
2025-11-25T22:45:44Z |
| last_indexed |
2025-11-25T22:45:44Z |
| _version_ |
1850572335358148608 |
| fulltext |
CHARACTERISTICS OF THE PLASMA CREATED BY ECR PLASMA
SOURCE FOR THIN FILMS DEPOSITION
V.D. Fedorchenko, O.V. Byrka, V.V. Chebotarev, I.E. Garkusha, V.I. Tereshin
Institute of Plasma Physics of the NSC KIPT, 61108, Kharkov, Ukraine
The construction of planar ECR plasma source with multipolar magnetic field is described and the distribution of
plasma parameters is measured. Plasma density and electron temperature at the distance 2,5 cm from the magnet surface
achieve 5×1010 сm-3 and 22,5 eV accordingly and they linearly decreased with the moving off from ECR zone. The
possibility of homogeneous and dense films deposition for both pure metals and alloys is shown.
PACS: 52.50.Dg; 81.15.Jj
1. INTRODUCTION
Development of the plasma assisted PVD and CVD
processes is accompanied by active elaboration and
investigation of the plasma sources of different kinds
including ECR type[1-7]. The planar ECR plasma sources
are of interest because they can be produced in the form
of assembling of separate moderate in size modules with
various space configurations depending on the
requirements of specific experiments.
In this work the plasma parameters of planar
rectangular ECR plasma source with multipolar magnetic
field were measured and explored. Preliminary
experiments on thin film deposition of pure metals and
NdFeB alloy were performed also.
2. THE PLANAR ECR PLASMA SOURCE
DESIGN
Scheme of the plasma source and experimental setup are
shown in Fig.1. The magnetic system of the planar plasma
source consists of 5 parallel rows of rectangular magnetic bars
with the length of 9cm each, disposed with a gap of 1cm. Each
magnetic bar consists of 3 Nd2Fe14B permanent magnets of 1×
1,2cm in cross section and 3cm in length. The base of the
magnet is the plane of 1×3cm. The magnetic bars are
magnetized in perpendicular to base direction i.e. in direction
of 1,2 cm. The e magnetic field on the magnet surface is 3 kG.
The permanent magnets are jointed butt (plane 1×1,2cm to
plane 1×1,2cm) with alternating polarities. The rows of the
magnetic bars are installed by such a way that the magnetic
field direction in each cross section is identical (see Fig.1).
The electromagnetic wave with frequency of 2,45GHz
is exited in the magnetic system by two-slot antenna,
which represents two rectangular copper channels
fastened to the copper basis of the plasma source. The
channel length is equal to the wavelength (12,5cm). The
width of the channel slot is 0,3cm and the height is equal
to a quarter of the wavelength. The antenna is installed so
as the slot channels are between magnetic bars on both
sides from the central bar. The channel output is aflush
with upper plane of the magnetic system (z=0).
The microwave power in the antenna is exited by the loop
on the terminal of the coaxial line. The coaxial line is
used also as the holder of all plasma source construction.
Second output of the coaxial line been situated outside of
the vacuum chamber is attached to a lateral wall of the
rectangular waveguide piece in which the microwave
power is launched by magnetron M105/1 attached to the
opposite lateral wall of the waveguide. Total power of the
magnetron is 600W. In Fig.1 the axis x of Cartesian
coordinates is in perpendicular to drawing direction, axis
y – along the drawing from left to right, axis z – in
vertical direction upward.
Macrowave
generator
vacuum
chamber
insulator
slot
antenna
electrostatic
analyzer
N N
S S
N NN
S S S
gas
diffusion
pump
Fig.1. Experimental set-up
With switching on the magnetron an electron
cyclotron resonance zone is formed above the slots. ECR
condition is reached in the region with magnetic field
intensity of 875 G where the electrons resonate at the
microwave frequency of 2,45 GHz. Part of the fast
electrons are trapped on magnetic field line and oscillated
between the magnetic cusps (mirror points of the
multipolar magnetic field). At the same time trapped
electrons undergo the electrical and gradient drift motion
and they are distributed along all magnetic structure
surface. The existence of the areas with minimum B in
longitudinal direction (axis x) promotes to the reduction
of fast electron losses to the wall of the chamber and the
construction elements. Thus the multipolar magnetic field
should increase the lifetime of fast electrons in the
resonance zone and thereby increase the ionization
probability by inelastic collisions with neutrals. The ECR
plasma source was introduced through the face flange into
the vacuum chamber with diameter of 20cm and length of
30cm. The vacuum chamber was pumped to background
pressure of 10-5 torr. Then the continuous flow of the
working gas was initiated with needle valve and a
pressure was reduced to a value of 1÷2×10-3torr (the
working pressure). Pure Ar, He, Kr were used as working
gases in these experiments.
Measurements of the plasma parameter were
performed by single and double Langmuir probes. All the
probes were able to move in z direction. Measurements
192 Problems of Atomic Science and Technology. 2005. № 1. Series: Plasma Physics (10). P. 192-194
of the plasma potential, the energy distribution of ions
and ion temperature were carried out by two-grid
electrostatic analyzer with retarding field.
3. EXPERIMENTAL RESULTS
Preliminary experiments demonstrated that plasma
density value and uniformity of created plasma layer are
defined by the location of the resonance zone with respect
to the magnetic structure plane (z=0). In optimal case
when the distance between magnet bars is 1cm and the
interface gap between magnets in the each magnet bars is
0,2 cm, the resonance zone (Bz=875G) is disposed
maximally above the magnetic plane (z=1cm). At such
configuration of the magnetic structure the primary
electrons are accelerated in the resonance zone, trapped
on the magnetic field lines and oscillated between
successive cusps getting over gradually to the rest of the
cusps and thus filling the all region of the magnetic field.
The created plasma is diffusively extended under the
action of the pressure gradient in perpendicular to the
magnet plane direction (z direction). With better plasma
confinement in the multipolar magnetic field a higher
density and electron temperature of the formed plasma are
observed and higher uniformity of plasma distribution in
the plane of magnetic structure is achieved. Visual
observation of the ECR discharge showed the
homogeneous plasma luminescence over the all plasma
source sections. At the same time the discharge was stable
and the consumable high frequency power did not change.
In these experiments all measurements were carried
out for z range from 2.5cm to 9cm from the magnet plane.
At the distance less than 2,5cm the electric probe
disturbed ECR discharge. The working pressure was
varied in the range from 1×10-3 to 3×10-3 torr. Transverse
size of the plasma with the uniform density is about 6x6
cm2 at the pressure 2×10-3torr and at position z=5cm.
Electron density ne for different working gases (Ar, He,
Kr) vs. the distance from the magnet plane is represented
in Fig.2. The curves for Ar and Kr are obtained at
pressure of 1×10-3 torr. For He the pressure was 3×10-3
torr. As it is seen the plasma density decreases practically
linearly with increasing the distance from ECR zone. It is
characteristic that the electron temperature behavior is
similar. At the distance z=2,5cm the electron temperature
is 22÷23eV practically for all gases and it decreases less
than two times moving away from magnet plane to 7,5cm.
Linear character of plasma density decreasing with the
distance from the resonance zone testifies to the diffusive
expansion of the plasma layer.
Analysis of the magnetic field structure shows that the
main magnetic field component is z-component (Hz≈
346Oe, Hy≈4,3Oe, Hx≈0,11Oe) already at the distance of
2,5 cm from the magnet plane i.e. the diffusive plasma
flows directly along the magnetic field. In this case the
diffusion coefficient along magnetic field coincides with
coefficient of ambipolar diffusion. The plasma diffusion
in the transverse direction was restricted due to
magnetization of electrons. Larmor radius of electrons at
2,5cm from the magnetic plane was estimated as 0,046cm
while the mean free path of electrons is much longer than
the size of experimental setup. Relatively slow
decreasing of electron temperature with moving away
from the resonance zone is explained by restriction of the
diffusive expansion of plasma in cross direction. On the
other hand the measured I-V characteristics show that
floating potential of the single Langmuir probe reaches up
to 6V and it has a positive polarity. The current density to
the probe at zero applied voltage is +3,5 mA/cm2. The
appearance of such current to the probe signifies that the
ion stream propagate from the resonance zone in z
direction. The value ion current does not changed
practically in the region of z=2,5- 9cm.
2 3 4 5 6 7 8
0
1
2
3
4
5
6
He
Ar
Kr
n,
1
010
cm
-3
Z, cm
Fig.2. Electron density vs. the distance from the magnetic
structure plane
The plasma potential and the energy characteristics of
ion component of diffusive plasma flow are measured
with electrostatic analyzer [8-10]. The I-V characteristic
of analyzer measured for different gases at the distance
of z=5cm are shown in Fig.3. The potential, at which
characteristic knee is arisen, determines the plasma
potential with high accuracy [10,11]. For example Ar
plasma potential is about 40V and it decreases with
moving away from the resonance zone. So at z=9cm the
plasma potential is as low as 20V. According to [12] the
plasma potential is defined as:
Up=Ufl+(kTe/e)Ln(0,77mi/me)1/2, where Up-the plasma
potential, Ufl-the floating potential, mi- ion mass (in our
case Ar), me-the electron mass. The estimations made on
the base of I-V characteristics give the values of Up that
are in agreement with electric probe measurements within
0,5V. When the analyzer is moved away from the
resonance zone the electron temperature decreases and, as
a consequence, the plasma potential falls too. Higher
ionization potential of working gas leads to smaller
plasma potential in the ECR discharge (Fig.3).
0 10 20 30 40 50 60
0
10
20
30
40
50
60
He
Ar
Kr
I,
µA
U, V
Fig.3. I-V characteristics for different gases
193
The function of the ion energy distribution along z
direction can be received by numerical differentiation of
the I-V characteristic [8]:
f(v)=Ami/e(-dI/dE)=mi/e2(-dI/dV),
where A is a constant depending on the aperture and
geometry of the analyzer, I- collector current, U-
retarding potential, E- energy ions in eV. Calculated from
I-V characteristic the energy of Ar ions is ~ 20 eV.
Assuming Maxwellian distribution function, the ion
temperature is kTi=-e/dlnI(U)/dU, where I is collector
current. At the distance of 3cm from the magnet plane the
ion temperature is estimated to be 3÷3,5eV.
4. THIN FILM DEPOSITION
In these experiments the target and the substrate were
inclined with respect to plasma layer and with each other.
The plate target (pure tungsten with the size of 5×5cm2 )
was arranged at the angle of 450 and at the distance of
5cm from the magnet plane. The substrate was placed at
the distance of 3cm from the target and it was practically
perpendicular to the magnet plane. The negative bias of
the target could be varied in wide range. The potential of
the substrate (copper sample treated with diamond lathe
tool) could be changed too. Roughness of the sample was
0.1µm. Deposition process was realized after ultrasonic
washing and ion etching. For comparison 2 regimes of
deposition were realized at the same amplitude of the
accelerating voltage (900V): with direct current bias
supplied to the target and with pulsating voltage with the
frequency of 100Hz (full-wave rectification).
Surface analysis of the deposited films shows that the
film produced in the pulsating regime is more
homogeneous. A small positive bias to the substrate still
more improve the quality of the film. The droplet fraction
is not observed. The structure of the tungsten film is not
visible even at the magnification 1000 of the optical
microscope that indicates fine crystalline structure of the
deposited film. The film thickness measured by the
optical interferometer is 2µm
In trial experiments on magnetic film deposition by
sputtering of Nd8Fe86B6 alloy target the surface analysis
also shows high quality of the deposited film, its
uniformity and cleanness. At the magnification of 1000
any droplets and fractions are completely absent. XRD
shows that the deposited magnetic film has the amorphous
structure.
5. CONCLUSIONS
ECR plasma source assigned for studying the different
cycles of plasma technology (cleaning and ion etching,
deposition of various materials including multiphase alloy
films) has been designed and investigated.
At the distance of 5cm from the magnet plane the
plasma density is up to 2,5×1010cm-3, the electron
temperature achieves 22÷23eV. Argon ion flux of
3,5mA/cm2 is obtained with ion energy of about 20eV.
The homogeneous range of this plasma flow is about 6×
6cm2.
The test experiments show the possibility of the
deposition of high quality coatings of different materials
including magnetic films on the base of the rare earth
compounds.
REFERENCES
1. N. Hershkowitz // IEEE Trans. Plasma Sci. (26). 1998,
p.1610-1620.
2. R.K. Waits // J.Vac. Sci.Technol. (15).1978, p.188.
3. J.Chapin and C.R.Condon. US Patent 4, 166,784, 1979
4. M.Shindo, M.Ishizone, Hkato, T.Mijazaki, A.Sakuma//
JMMM 161 1996, L1-L5.
5. J.N.Matossian // J.Vac.Sci.Technol. B 12. 1994, p.850.
6. N.V. Konilov, Ya.L.Linettsky // JMMM 127. 1993,
p.289-297.
7. A.S.Lileev, A.A.Parilov, N.M.Medvedeva, V.G.Blatov
// XIIIth Inter. Conf. On Perm. Magn. Susdal, 2000, 135.
8. С.Bohm and J.Perrn// Rev. Sci. Instrum. 1993, 64(1),
p.31-44.
9. C. Charles// J. Vac. Sci. Technol. A 11. 1993, p.157.
10.E.Leal-Quiros and M. A. Prelas // IEEE Transactions
on plasma science (16). 1988, p.661.
11. A. Fredriksen, A. Aaneslend, G. Hellblom and K.
Rypdal // Proceedings of the 1998 ICPP and 25th EPS
Conf. On Contr. Fusion and Plasma Physics, Praha./
ECA 22C, 1998, p.2789.
12. I. Beilis, R. Boxman and S. Goldsmith// J. Appl. Phys.
88, 11, 2000, p.6224.
ХАРКТЕРИСТИКИ ПЛАЗМЫ, СОЗДАННОЙ ЭЦР ПЛАЗМЕННЫМ ИСТОЧНИКОМ ДЛЯ
НАНЕСЕНИЯ ТОНКИХ ПЛЕНОК
В.Д. Федорченко, О.В. Бырка, В.В. Чеботарев, И.Е. Гаркуша, В.И. Терешин
В работе описана конструкция планарного ЭЦР плазменного источника с мультипольным магнитным полем и
измерены распределения параметров создаваемой плазмы. На расстоянии 2,5 см от поверхности магнитов
плотность плазмы и электронная температура 5*1010 см-3 и 22,5 еВ соответственно, которые линейно спадают
при удалении от ЭЦР зоны. Показана возможность напыления однородных и плотных пленок, как чистых
металлов, так и сплавов.
ХАРАКТЕРИСТИКИ ПЛАЗМИ СТВОРЕНОЇ ЕЦР ПЛАЗМОВИМ ДЖЕРЕЛОМ ДЛЯ НАНЕСЕННЯ
ТОНКИХ ПЛІВОК
В.Д. Федорченко, О.В. Бирка, В.В. Чеботарьов, І.Є. Гаркуша, В.І. Терьошин
В роботі розглянута конструкція планарного ЕЦР плазмового джерела з мультипольним магнітним полем та
виміряно розподіл параметрів створюваної плазми. На відстані 2,5 см від поверхні магнітів густина плазми та
електронна температура 5 *1010 см-3 та 22,5 еВ відповідно, які лінійно зменшуються при віддаленні від ЕЦР
зони. Показана можливість нанесення однорідних та щільних плівок, як чистих металів, так і сплавів.
194
|