Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge
Experimental results on study of the nonself-sustained arc discharge basic characteristics at currents up to 35 A are presented. The ion energy distributions and dynamics of the directed motion average energy of plasma flow ions are studied. Floating potentials in the plasma flows are measured. Ioni...
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2015
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| Cite this: | Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge / A.G. Borisenko, Yu.S. Podzirei // Вопросы атомной науки и техники. — 2015. — № 1. — С. 177-180. — Бібліогр.: 7 назв. — англ. |
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| citation_txt | Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge / A.G. Borisenko, Yu.S. Podzirei // Вопросы атомной науки и техники. — 2015. — № 1. — С. 177-180. — Бібліогр.: 7 назв. — англ. |
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| description | Experimental results on study of the nonself-sustained arc discharge basic characteristics at currents up to 35 A are presented. The ion energy distributions and dynamics of the directed motion average energy of plasma flow ions are studied. Floating potentials in the plasma flows are measured. Ionization coefficients of the generated plasma flows and their dependence on the discharge current are studied. It is shown that at the discharge currents equal 20…30 A the vacuum arc discharge in anode material vapors can effectively create dropless and highly ionized plasma flows of different metals and provides films deposition rates, which are comparable to possibilities of the cathode vacuum arc discharge.
Представлены результаты исследований основных характеристик несамостоятельного дугового разряда при токах до 35 А. Приведены функции распределения ионов по энергиям, измеренным в создаваемых плазменных потоках при разных значениях тока разряда и показана динамика энергии направленного движения ионов. Определены значения плавающего потенциала. Показано, что при токах 20…30 А вакуумный дуговой разряд в парах материала анода позволяет эффективно создавать бескапельные высокоионизованные потоки плазмы разных металлов и обеспечивать скорости роста осаждаемых покрытий, сравнимые со скоростями роста, обеспечиваемыми в технологиях с катодной формой вакуумной дуги.
Представлено результати досліджень основних характеристик несамостійного дугового розряду при струмах до 35 А. Наведені функції розподілу іонів за енергіями, виміряними в створюваних плазмових потоках при різних значеннях струму розряду і показана динаміка енергії спрямованого руху іонів. Визначено значення плаваючого потенціалу. Показано, що при струмах 20…30 А вакуумний дуговий розряд у парах матеріалу анода дозволяє ефективно створювати безкрапельні високоіонізовані потоки плазми різних металів і забезпечувати швидкості росту покриттів, які є порівняними зі швидкостями росту плівок, що забезпечуються в розрядах з катодною формою вакуумної дуги.
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ISSN 1562-6016. ВАНТ. 2015. №1(95)
PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2015, № 1. Series: Plasma Physics (21), p. 177-180. 177
ION ENERGY DISTRIBUTION AND BASIC CHARACTERISTICS
OF PLASMA FLOWS OF NONSELF-SUSTAINED ARC DISCHARGE
A.G. Borisenko, Yu.S. Podzirei
Institute for Nuclear Research NAS of Ukraine, Kyiv, Ukraine
E-mail: boris@kinr.kiev.ua
Experimental results on study of the nonself-sustained arc discharge basic characteristics at currents up to 35 A
are presented. The ion energy distributions and dynamics of the directed motion average energy of plasma flow
ions are studied. Floating potentials in the plasma flows are measured. Ionization coefficients of the generated
plasma flows and their dependence on the discharge current are studied. It is shown that at the discharge currents
equal 20…30 A the vacuum arc discharge in anode material vapors can effectively create dropless and highly
ionized plasma flows of different metals and provides films deposition rates, which are comparable to possibilities
of the cathode vacuum arc discharge.
PACS: 52.50.Dg, 52.80.Vp
INTRODUCTION
Formation of functional metal films of various
solid-state materials for needs of nano- and
microelectronics requires the use of plasma sources in
which plasma streams there are no material drops.
Physical processes that occur in the widely used arc
discharge in cathode material vapors, always create
plasma flows with the drops of cathode material [1-4].
Droplet sizes vary from a few to tens of microns.
Proportion of the droplets of diameter greater than 2
microns in the total weight of the transported material
can reach 90% [1]. Therefore, these flows can not be
used to solve a number of technological problems and
they require development and application of various
additional filtering methods [2-4]. However, filtration of
flows not only removes the drop phase of working
material, but also leads to a significant decrease in the
plasma flow intensity at the filter outlet [4, 5]. The
nonself-sustained arc discharge in anode material vapors
is characterized by diffuse current binding at the anode
and generates plasma flows without drops [6]. The
mode of local vaporization of the anode material
working surface in this type discharge virtually is absent
[7]. At the moment, information about the ion energies
in plasma flows generated by this type discharge is
absent. Also there are no data on characteristics of such
a discharge at currents more than 10 A. That is why
their study is important from both fundamental and
applied perspectives.
1. EXPERIMENTAL SETUP
A scheme of the used experimental device is shown
in Fig.1. The discharge was ignited between an anode 3,
which was water cooled, and a grounded heated cathode
1 in vapors of working material 2. The working material
2 was placed directly on the anode of the discharge. In
experiments described here the working material was
nickel or titanium. Thermoelectrons from the cathode
reached the working material and heated it up. The
discharge initiation took place when the pressure of
working material vapors achieved a certain level. The
distance between the cathode and working material
constituted 5…10 mm. Crossed electric and magnetic
fields in the discharge zone were used for simplification
of discharge ignition and for control of generated
plasma flows parameters. They were created by a
cylindrical electrode 4 and the magnetic field coil 5. The
electric potential of the electrode 4, U4, was changing
Fig. 1. Scheme of experimental device.
1 – heated cathode; 2 – working material; 3 – cooled
anode; 4 – cylindrical electrode; 5 – magnetic coil;
6 – analyzer or a flat Langmuir probe;
7 – substrate holder-ion collector
relative to the potential of the grounded discharge
cathode. The magnetic field, B, in the area of the
discharge gap was B = 8×10
−3
T and corresponded to
the maximum of ion current to the collector 7 at a fixed
discharge current. An additional discharge in the
crossed electric and magnetic fields was ignited when
applying a positive potential to the cylindrical electrode
4. A flat electric probe 6 was used to measure
parameters of the plasma flows. The probe was placed
on the axis at a distance of 17…19 cm from the anode
or 9…11 cm from the upper surface of the electrode 4.
Potential of the probe when measuring the ion current
was typically U6 = -200 V. Energy spectra of ions were
measured using a 4-electrode electrostatic analyzer.
Deposition rates of the films, q, which are listed in the
work are averages over the dielectric substrate surface
of size 4.8×6 cm. The substrates were placed on the
electrode 7 at a distance 18…18.5 cm from the anode.
Geometric dimensions of the described plasma source
do not exceed the dimensions of a cylinder of diameter
mailto:boris@kinr.kiev.ua
178 ISSN 1562-6016. ВАНТ. 2015. №1(95)
17 and 20 cm in height. Therefore, the device can easily
be placed in a vacuum chamber for vacuum deposition.
The gas pressure in the discharge chamber was close to
the ultimate vacuum and was not more than 1×10
−3
Pa.
When working with titanium in sputtering mode the
pressure in the vacuum chamber diminished by about 10
times. The cathode of discharge in these experiments
worked in a free mode when the thermoelectron
emission current from the cathode exceeded the total
current of primary and secondary discharges.
2. EXPERIMENTAL RESULTS
The volt-ampere characteristic (VAC) of the nonself
sustained arc discharge in nickel vapors, that is the
dependence of the discharge voltage, Ud, on the value of
the discharge current Id, is shown in Fig. 2, curve 1. As
you can see VAC characteristics of this type discharge
have an appearance typical of vacuum arcs. Increase in
the discharge current is accompanied by a decrease in
the discharge voltage. In our case, at increase in the
discharge current from 12 to 35 A the discharge voltage
decreased from 180 to 85 V. VAC characteristics of the
described discharge is radically different from the VAC
characteristics of the nonself-sustained arc discharge in
gases. In the case of gas discharge the voltage is
increased by the rise of discharge current.
Fig. 2. Discharge voltage Ud and ion current to the
substrate holder Isub vs discharge current Id
The increase in discharge current is accompanied
by an increase of the ion current to the ion collector 7
(Fig. 2, curve 2). The ion current density on the
electrode 7 increased from 0.4 to 2.9 mA/cm
2
, which is
about 7 times.
Fig. 3. Floating probe potential Vf on the value
of discharge current Id
Throughout the investigated range of the discharge
current the potential of the isolated probe was negative
and was equal to -(35…45) (Fig. 3). The floating
potential value varies slightly according to the diameter
of the plasma flow. These data show that the plasma
stream, created by the given discharge has neutralized
space charge and it can be successfully used for films
deposition on substrates of any material, not only on
metals and semiconductors, but also on dielectrics. The
growth rates of the nickel and titanium films on
dielectric substrates, for various discharge currents are
shown in Fig. 4. As it can be seen from the figure, even
at discharge currents from 10 to 35 A the generated
plasma flows can be used for deposition of nickel films
with growth rates qNi = (1.5…5.5)×10
−6
m/h or qNi =
(4…15) ×10
−10
m/s (see Fig. 4, curve 1). In the case of
titanium deposition the films growth rates are qTi =
(2…10)×10
−6
m/h or qTi =(5…27)×10
−10
m/s (see Fig. 4,
curve 2).
Fig. 4. Rate of films deposition q on the discharge
current Id for Ni and Ti as a working material
Both dependences are nonlinear. The initial linear
growth of q at discharge currents greater than 25 A is
replaced by more rapid growth. This fact is interesting
from the fundamental point of view, since a linear
dependence of the growth rate of deposited films on the
discharge current value usually presented in the vacuum
arc discharge. This is also important from a practical
point of view, because it suggests the possibility of
increasing economic efficiency of industrial
equipment’s, which are developed on the basis of the
described type discharge. Therefore, further
investigations of the discharge, including this feature are
appropriate and necessary. Results of the growth rate
measurements and measured value of ion currents to the
substrate allowed to determine the ionic fraction in a
plasma stream that is factor of ionization of a plasma
stream, α. Calculations of α have been made taking into
account the process of ion sputtering of films material.
More detailed methodology of α measurement and
calculation is described in [6]. The results of
measurements for nickel are shown in Fig. 5. The
measurements were made at zero potential of the
cylindrical electrode 4. The data of Fig. 5 indicate that
variation of the discharge current can significantly
increase α. It can be seen that ionization coefficient of
the plasma flow in a discharge in nickel vapors is about
45% at a discharge current of 10 A and increases almost
linearly with the discharge current. It reaches values of
the order of 100% at a current of
ISSN 1562-6016. ВАНТ. 2015. №1(95) 179
30 A. That is, this discharge really produces highly
ionized flows of metal plasma.
Fig. 5. Ionization coefficient of plasma flow α vs
discharge current Id for Ni
The ion energy distributions in the plasma flows
generated at different discharge currents in the nickel
vapors are shown in Fig. 6. They have been calculated
from the decay curve of collector ions obtained by four-
electrode electrostatic analyzer. It is seen that the ions
with energies greater than the discharge voltage are
absent, in contrast to the vacuum arc discharge in vapor
of the cathode material. This indicates that in this
discharge the ions leaving the anode surface also absent.
Fig. 6. Ion energy distribution fi for various discharge
currents Id at U4 = 0: 1 – Id = 12 A; 2 – Id = 15 A;
3 – Id = 20 A
Thus, formation of the discharge working medium
occurs by evaporation of the anode material and
subsequent ionization of the vapor in the discharge gap
zone. The experiments show that the top of the energy
distribution of nickel ions decreases with increasing the
discharge current. This was also supported by data of
Fig. 6. The maximum of ion energy distribution at
discharge current of 12 A corresponds to an energy of
100 eV. Increasing the discharge current to 15 A, and
then to 20 A leads to a displacement of this peak to the
energy of 80 and 60 eV.
Presence of a positive potential on the cylindrical
electrode 4 leads to ignition of an additional discharge
in the crossed longitudinal magnetic and transversal
electric fields. The increase in the potential of electrode
4 induced a small reduction of the discharge potential.
The additional discharge not only made it easier the
ignition of the main discharge, but it also allowed to
influence on certain parameters of the created plasma
streams. Fig. 7 (curve 1) shows the values of α and qNi
at the fixed current of main discharge Id = 10 A and at
different values of the additional discharge current I4.
Fig. 7. Ionization coefficient of plasma flow α and rate
of Ni film deposition q vs current of additional
discharge I4
It is see that the additional discharge even at low
currents can significantly affect on the α and change its
value from 58 to 82%, which is almost 1.5 times. From
the data of Fig. 7, curve 2, it is visible that increase of α
takes place at almost stable rate of films deposition q: at
presented conditions the reduction of q is not more than
10 % of its initial value. The influence of the additional
discharge on ion energy distribution is shown in Fig. 8.
Fig. 8. Ion energy distribution fi for various additional
discharge currents I4: 1 – I4 = 0; 2 – I4 = 2 A
Here there are energy distributions of Ni ions, measured
at the main discharge current Id = 15 A, and in the
absence (curve 1) or in the presence of the additional
discharge with current of I4 = 2.5 A (curve 2). The
potential of the cylindrical electrode 4 in this case had
been changed from 0 to 110 V. It is evident that
additional discharge apparently has a little effect on the
ion energy distribution of the main discharge. In this
case, there is only a slight shift of the ion distribution
function peak to higher energies, which does not exceed
10 V (from 80 to 90 V).
CONCLUSIONS
The results of experimental studies of the main
characteristics and the energy spectra of ions in a
plasma of the nonself-sustained vacuum arc discharge
with currents up to 35 A are presented. It has been
established, that in the generated plasma streams the
ions, with energies equal or greater than the discharge
voltage, are absent. This indicates that the discharge
180 ISSN 1562-6016. ВАНТ. 2015. №1(95)
does not contain the ions which enter into the discharge
zone directly from the anode surface. The obtained data
also indicate that the basic physical mechanism
providing formation of the discharge working medium
is evaporation of the anode material. The most probable
mechanism of plasma formation is ionization of atoms
of working substance directly in the discharge zone.
The ion energy distributions were measured and it was
established that the maximum of ion distribution shifted
to smaller values at increase of the discharge current.
That is, a decrease in the directed motion energy of ions
takes place. It was shown that even at currents of
20…30 A the discharge generated highly ionized
plasma streams, and could provide deposition rates of
metallic films that were comparable with possibilities
of the vacuum cathode arcs. The data presented in this
article shows that the further researches of plasma
sources on the basis of the nonself- sustained arc
discharge in vapors of anode material are actual and
necessary.
REFERENCES
1. V.M. Khoroshikh. The droplet phase of cathode
erosion in steady-state vacuum arc // Physical surface
engineering. 2009, v. 7, № 1-2, p. 54-59.
2. D.S. Aksenov, I.I. Aksenov, V.Е. Strel'nitskij. Noise
emissions of particulate matter in the vacuum arc
plasma sources // PAST. 2007, № 6, p. 106-115.
3. R.L. Boxman, D.M. Sanders, and P.J. Martin.
Handbook of Vacuum Arc Science and Technology.
Noyes Publications, Park Ridge, N.J., 1995.
4. A. Anders. Cathodic Arcs: From Fractal Spots to
Energetic Condensation. New York: “Springer”,
2008, ISBN 978-0-387-79107-4.
5. V.M. Khoroshikh, A.A. Komar, V.A. Brovina. About
efficiency of vacuum-arc plasma sources with
separation of drop- phase cathode erosion // Physical
surface engineering. 2009, v. 7, № 1-2, p. 54-59.
6. A.G. Borisenko, V.A. Saenko, V.A. Rudnitsky.
Nonself-sustained arc discharge in anode material
vapors // IEEE Trans Plasma Science. 1999 August,
v. 27, №4, p. 877-881.
7. A.G. Borisenko, V.A. Saenko, J.S. Podziray.
Destruction of the arc discharge in vapors of the anode
material by the gas entering into the vacuum chamber //
Proceeding Int. Conf. on Plasma of Low Temperature
Plasma, PLTP-03, Kyiv, Ukraine, May 11-15. 2003,
p. 6-2-5.
Article received 23.11.2014
РАСПРЕДЕЛЕНИЕ ИОНОВ ПО ЭНЕРГИЯМ И ОСНОВНЫЕ ХАРАКТЕРИСТИКИ
ПОТОКОВ ПЛАЗМЫ НЕСАМОСТОЯТЕЛЬНОГО ДУГОВОГО РАЗРЯДА
А.Г. Борисенко, Ю.С. Подзирей
Представлены результаты исследований основных характеристик несамостоятельного дугового разряда
при токах до 35 А. Приведены функции распределения ионов по энергиям, измеренным в создаваемых
плазменных потоках при разных значениях тока разряда и показана динамика энергии направленного
движения ионов. Определены значения плавающего потенциала. Показано, что при токах 20…30 А
вакуумный дуговой разряд в парах материала анода позволяет эффективно создавать бескапельные
высокоионизованные потоки плазмы разных металлов и обеспечивать скорости роста осаждаемых
покрытий, сравнимые со скоростями роста, обеспечиваемыми в технологиях с катодной формой вакуумной
дуги.
РОЗПОДІЛ ІОНІВ ЗА ЕНЕРГІЯМИ ТА ОСНОВНІ ХАРАКТЕРИСТИКИ ПОТОКІВ ПЛАЗМИ
НЕСАМОСТІЙНОГО ДУГОВОГО РОЗРЯДУ
А.Г. Борисенко, Ю.С. Подзирей
Представлено результати досліджень основних характеристик несамостійного дугового розряду при
струмах до 35 А. Наведені функції розподілу іонів за енергіями, виміряними в створюваних плазмових
потоках при різних значеннях струму розряду і показана динаміка енергії спрямованого руху іонів.
Визначено значення плаваючого потенціалу. Показано, що при струмах 20…30 А вакуумний дуговий розряд
у парах матеріалу анода дозволяє ефективно створювати безкрапельні високоіонізовані потоки плазми
різних металів і забезпечувати швидкості росту покриттів, які є порівняними зі швидкостями росту плівок,
що забезпечуються в розрядах з катодною формою вакуумної дуги.
http://ru.wikipedia.org/wiki/%D0%A1%D0%BB%D1%83%D0%B6%D0%B5%D0%B1%D0%BD%D0%B0%D1%8F:%D0%98%D1%81%D1%82%D0%BE%D1%87%D0%BD%D0%B8%D0%BA%D0%B8_%D0%BA%D0%BD%D0%B8%D0%B3/9780387791074
|
| id | nasplib_isofts_kiev_ua-123456789-82145 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-12-02T12:45:48Z |
| publishDate | 2015 |
| publisher | Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| record_format | dspace |
| spelling | Borisenko, A.G. Podzirei, Yu.S. 2015-05-25T15:29:18Z 2015-05-25T15:29:18Z 2015 Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge / A.G. Borisenko, Yu.S. Podzirei // Вопросы атомной науки и техники. — 2015. — № 1. — С. 177-180. — Бібліогр.: 7 назв. — англ. 1562-6016 PACS: 52.50.Dg, 52.80.Vp https://nasplib.isofts.kiev.ua/handle/123456789/82145 Experimental results on study of the nonself-sustained arc discharge basic characteristics at currents up to 35 A are presented. The ion energy distributions and dynamics of the directed motion average energy of plasma flow ions are studied. Floating potentials in the plasma flows are measured. Ionization coefficients of the generated plasma flows and their dependence on the discharge current are studied. It is shown that at the discharge currents equal 20…30 A the vacuum arc discharge in anode material vapors can effectively create dropless and highly ionized plasma flows of different metals and provides films deposition rates, which are comparable to possibilities of the cathode vacuum arc discharge. Представлены результаты исследований основных характеристик несамостоятельного дугового разряда при токах до 35 А. Приведены функции распределения ионов по энергиям, измеренным в создаваемых плазменных потоках при разных значениях тока разряда и показана динамика энергии направленного движения ионов. Определены значения плавающего потенциала. Показано, что при токах 20…30 А вакуумный дуговой разряд в парах материала анода позволяет эффективно создавать бескапельные высокоионизованные потоки плазмы разных металлов и обеспечивать скорости роста осаждаемых покрытий, сравнимые со скоростями роста, обеспечиваемыми в технологиях с катодной формой вакуумной дуги. Представлено результати досліджень основних характеристик несамостійного дугового розряду при струмах до 35 А. Наведені функції розподілу іонів за енергіями, виміряними в створюваних плазмових потоках при різних значеннях струму розряду і показана динаміка енергії спрямованого руху іонів. Визначено значення плаваючого потенціалу. Показано, що при струмах 20…30 А вакуумний дуговий розряд у парах матеріалу анода дозволяє ефективно створювати безкрапельні високоіонізовані потоки плазми різних металів і забезпечувати швидкості росту покриттів, які є порівняними зі швидкостями росту плівок, що забезпечуються в розрядах з катодною формою вакуумної дуги. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Низкотемпературная плазма и плазменные технологии Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge Распределение ионов по энергиям и основные характеристики потоков плазмы несамостоятельного дугового разряда Розподіл іонів за енергіями та основні характеристики потоків плазми несамостійного дугового розряду Article published earlier |
| spellingShingle | Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge Borisenko, A.G. Podzirei, Yu.S. Низкотемпературная плазма и плазменные технологии |
| title | Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge |
| title_alt | Распределение ионов по энергиям и основные характеристики потоков плазмы несамостоятельного дугового разряда Розподіл іонів за енергіями та основні характеристики потоків плазми несамостійного дугового розряду |
| title_full | Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge |
| title_fullStr | Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge |
| title_full_unstemmed | Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge |
| title_short | Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge |
| title_sort | ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge |
| topic | Низкотемпературная плазма и плазменные технологии |
| topic_facet | Низкотемпературная плазма и плазменные технологии |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/82145 |
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