RU2423754C2 - Method and device to manufacture cleaned substrates or pure substrates exposed to additional treatment - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: substrates cleaning with plasma etching is carried out on a plasma discharge plant, comprising a cathode source of electrons (5) and an anode structure (7). The anode structure (7) comprises, at one side, an anode electrode (9), and on the other side, a limiter (11), which is electrically isolated from it. The limiter (11) has a hole (13), directed towards the area (S) of the substrate (21) to be cleaned. Power supply to a cathode source of electrons (5) and an anode electrode (9) is sent via a supply circuit from a source of supply (19). The circuit is controlled in electric buffer mode.

EFFECT: provision of higher density of plasma etching directly near the cleaned area of the substrate and achievement of improved even cleaning both inside reliefs and of protruding parts on the considered area of the surface.

44 cl, 10 dwg

Description

The present invention, in a first aspect, relates to the manufacture of at least one cleaned substrate, especially cutter parts that are so cleaned, the cleaned substrates of which can be subjected to further processing before and / or after cleaning, for example by heating and / or applying coverings on them. The cleaning process that is used to produce the substrates thus cleaned is, generally speaking, plasma etching, both non-reactive and reactive. According to the first object of the present invention, the object of the present invention is to provide an increased plasma etching density directly at the surface region of the substrate to be cleaned and to achieve improved uniform cleaning both inside the reliefs and protruding parts on the surface region under consideration, especially, for example, on the cutting edges of the substrate of the tool parts.

According to a first aspect of the present invention, this object is achieved by a method of manufacturing at least one peeled substrate or a substrate obtained as a result of further processing of a substrate so cleaned in a manner that comprises the following.

In a vacuum chamber having a reaction zone and containing a gas for ionization, at least one plasma discharge is generated between at least one cathode electron source and at least one anode structure containing at least one anode electrode;

• increase the electron density and, thus, the ion density directly near at least one anode structure using a stopper having a hole open in the direction of the reaction zone and containing at least one anode electrode;

• provide for the presence of the anode electrode inside the limiter and act on this limiter with an electric potential different from the electric potential applied to the anode electrode, thereby concentrating the increased ion density in the limiter and in the immediate vicinity of its opening;

• place the substrate with the supply to it of a negative electric potential, at least averaged over time, and with respect to the electric potential of the anode electrode;

• place at least the cleaned area of the substrate surface for a predetermined cleaning time under the influence of the region of increased ion density and in the immediate vicinity of the hole, thereby being substantially closer to the hole than to the cathode electron source.

According to German patent DE 42 28 499, the plasma cleaning of the substrates is carried out by creating a plasma discharge between the hollow cathode and a generally flat anode facing the hollow cathode along the discharge axis. The substrates are placed in a vacuum chamber at a distance from and along the axis of the discharge.

According to the following reference, oriented generally to plasma cleaning, in German patent DE 41 25 365, which is consistent with US patent US-A-5 294 322, the first plasma discharge is created between the vaporized target and the wall of the vacuum chamber acting as an anode with using the first power source. For cleaning purposes, a shutter is positioned between the vaporized target and the substrates. The second anode electrode is U-shaped, and in order to clean it, it is put into operation from a second additional power source with an anode potential relative to the wall of the vacuum chamber. The substrates are put into operation using a third power source with a cathode potential relative to the considered wall.

Further attention is drawn to US Pat. No. 5,503,725.

According to the present invention, in one embodiment, the considered plasma discharge is generated as a low-voltage discharge with a voltage U _AUX between the anode electrode and the cathode electron source, the value of which is:

20 V ≤ U _AC ≤ 100 V,

however, in the following embodiment:

35 V ≤ U _AC ≤ 70 V.

Definition

Each time, throughout the disclosure of the content and claims of the present invention, when considering the values of voltage, current or electric potential, you should refer to their rms value (RMS). For the definition of the mean square value, a link is provided, for example, to Wikipedia http://en.wikipedia.org/wiki/ROOT MEAN SQUARE.

In a further embodiment, the anode electrode and the cathode electron source are put into operation by a power circuit with floating electrical potentials.

Thus, only one power source is used, and the cathode source of electrons, with a certain potential difference, “sees” only one anode electrode, which is the considered anode electrode inside the limiter.

Despite the fact that the limiter in question can be triggered by means of an additional power supply by supplying a pre-set, possibly adjustable electric potential, which is different from the electric potential of the anode electrode, in one embodiment, the limiter in question is at a floating electric potential.

In this case, the limiter in question is made of metal or of a dielectric material in its bulk, while at least part of its surface is metal. Perhaps it can even be made of a dielectric material.

In one embodiment, the interior of the limiter in question is selected mainly in a U-shape in at least one section plane. An anode electrode is proposed that is located at a distance from the bottom and along the bottom of the internal U-shaped space, which is still considered in the discussed section plane.

Further, in one embodiment, the U-shaped interior in question is shaped like a trough in a perpendicular view of the sectional plane under discussion.

In a further embodiment, direct current is applied to the anode electrode relative to the cathode electron source in a pulsed mode. Thus, it becomes possible, on the one hand, to generate high-density plasma inside and in close proximity to the limiter in question and, on the other hand, to limit the heating of the limiter and the anode electrode under control.

In a further embodiment, at least one of the direct current values, the amplitude of the pulses relative to the direct current value, the pulse repetition rate, the pulse duration or the maximum load, the pulse shape is adjustable. Thus, in one embodiment, the considered pulse repetition rate is selected in the range:

0.2 Hz ≤ f ≤ 200 kHz.

In yet another embodiment of the method of the present invention, in which the internal space of the limiter is selected, mainly U-shaped, in at least one plane of section and in which an anode electrode is located at a distance from the bottom and along the bottom of the inner U -shaped space, considered, moreover, in the sectional plane under discussion; the anode electrode has a length of W _AN , and the bottom of the internal space of the limiter has a length of W _CO , and these values are selected so that the ratio is valid:

W _AN <W _CO ≤ W _AN + 2 DSD.

DSD is the thickness of the dark space under the operating conditions of the method carried out in a vacuum chamber.

The thickness of the dark space under certain operating conditions is about 0.5 mm to 10 mm with a total pressure in the vacuum chamber of 0.1 Pa to 10 Pa. The thickness of the dark space is approximately 1 mm to 10 mm for a total pressure of 0.1 Pa to 3 Pa.

In front of the surfaces of the two electrodes with which a plasma discharge is generated, a region is formed, which is called, as the experienced operator knows, "electrode dark space". The length of this electrode dark space, mainly perpendicular to the surface of the electrode, is the thickness of the dark space. It is in this space that a significant drop in the electrode potential occurs, namely, between the plasma potential and the electrode surface potential. Thus, it is in this place that charged particles are accelerated by an electric field, which is formed as a result of a drop in the electrode potential in the dark electrode space.

In a further embodiment, the shoulder length of the inner U-shaped space - L is selected according to the ratio:

0.5 W _AN ≤ L ≤ 1.5 W _AN .

In another embodiment, the surface region of the substrate to be cleaned is distant from the plane defined by the stopper hole by a distance d that is selected:

2 cm ≤ d ≤ 10 cm.

In a further embodiment of the method described in the present invention, such power is supplied to the anode electrode relative to the cathode electron source to obtain a current density per unit area of the anode of at least 0.5 A / cm ² . In this case, the upper limit for such a current density is primarily limited by the efficiency of the heating limiting measuring instruments installed in the anode structure.

In a further embodiment, applying a power supply between the anode electrode in question and the cathode electron source creates a drop in the anode potential from 50 V to 100 V (including both limits). In this case, in the zone of the anode dark space, the electrons are strongly accelerated towards the anode electrode, leading to a high degree of ionization of gas molecules in this dark anode space.

In one embodiment, at least one cathode electron source is selected to generate substantially only electrons. Such a source may, for example, be a direct filament thermoelectrode cathode or a hollow cathode. Since it cannot be ruled out that due to collisions of positive ions with the cathode, such a cathode will also emit particles of its material, such a source is defined as emitting “mainly” only electrons.

In a further embodiment, the at least one cathode electron source is selected as a cathode emitting electrons and source material. In this case, the coating on the substrate is prevented by means of a controllably movable shutter. Moreover, such a cathode source of electrons can, for example, be made as a sputtering target, while the target is either non-magnetron or magnetron sputtering or a sputtering target in an arc discharge. In this case, for the cleaning process according to the present invention, the corresponding targets are activated only together with the considered anode electrode located in the limiter.

In a further embodiment, a DC bias voltage, a combination of direct and alternating current or alternating current, is applied to the substrate, moreover, preferably, the bias voltage of the direct current with superimposed pulses.

In a further embodiment of the method of the present invention, the substrates are further processed in at least one of the following process steps:

• cleaning by metal ion etching, in which the cathode is selected as the cathode source of electrons, which emits electrons and the source metal, in which the flow of metal particles from the considered cathode to the considered anode electrode is only limited but not prevented;

• heating, in which the anode electrode, as considered, is turned off and the substrate is activated as the anode electrode relative to the cathode electron source;

• coating.

Thus, for the purpose of coating, whenever the cathode source of electrons is made, for example, as a target of a sputtered source or a source vaporized in an arc discharge, an anode electrode with a limiter as an anode relative to the target cathode under consideration is introduced into the operation during the cleaning process , whereas during the coating operation, the anode electrode with the limiter is disconnected and a special anode is connected, such as, for example, the wall of the vacuum chamber relative to the sprayed cathode or, respectively , cathode of evaporation in an arc discharge.

In fact, the coating mode can be performed by various technologies:

a) the cathode electron source emits material, and the anode electrode is disconnected. Instead, an anode is connected, which is intended only for a source of material containing a cathode source of electrons.

b) The cathode electron source emits material, and the anode electrode is left connected. Such a coating process is similar to ion plating.

c) The cathode mainly emits electrons, the anode electrode is connected. A gas is supplied to deposit a coating therefrom, such as, for example, a carbon coating gas, for example methane or acetylene, or a mixture thereof. This gas decomposes in the immediate vicinity of the anode electrode, so that a coating is formed, for example, with diamond-like carbon (DLC). This method is fundamentally consistent with plasma chemical vapor deposition (PECVD).

d) The cathode source of electrons emits electrons and material. The anode electrode is connected. The gas from which the coating is deposited, or the reaction gas, is supplied to the vacuum chamber.

f) The cathode electron source and the anode electrode in question are both disconnected. A separate source of coating material was put into operation.

In a further embodiment, an auxiliary anode electrode is provided in a vacuum chamber. The process of occurrence and development of arcing, which means "disturbing" arcing, is prevented by the interruption of the operation of the anode electrode, which is active during processing of the substrate, whether it is cleaning, etching by metal ions, heating or coating, for the first time period and is replaced by process of auxiliary anode electrode.

In this case, the first time interval during which the auxiliary anode replaces the operation of the process anode is selected shorter than the second time intervals immediately before and after the first time interval considered, and during these second time periods the substrate is processed.

In a further embodiment, departing from the aforementioned embodiment with an auxiliary cathode functioning, the anode electrode that is active during the processing of the substrate is an anode electrode of the anode structure, thus interacting with the considered limiter, and the auxiliary anode electrode is placed much closer in the cathode source of electrons than to the anode structure.

In another embodiment, the considered switching from the anode electrode functioning during the processing of the substrate to the auxiliary anode for the considered first time interval is controlled in at least one of the following modes:

• in prevention mode, where the switch is constantly controlled by a timer, for example, periodically, during the processing process;

• in the limiting mode, where arcing is not prevented, but is quickly detected by the arcing detector, and as soon as the onset of arcing is detected, its further development is interrupted by switching from the anode electrode functioning during processing to the auxiliary anode.

In order to just prevent the damage to the technological process due to unwanted arcing, with a more general approach, one electrode of a pair of electrodes participating in the plasma treatment of the substrate is disconnected for a relatively short first period of time and its functioning is replaced by connecting an auxiliary electrode to work . Such a general approach for preventing damage caused by an arc is considered as a second object of the present invention, patentable per se, and comprises a method for preventing disruption of the processing process due to undesired arcing during vacuum treatment in a plasma discharge of at least one substrate, in accordance with which the plasma is generated with the participation of at least two electrodes, a method that includes disabling one of the at least two electrodes and, instead of Moreover, the auxiliary electrode is connected to the operation for the first time interval, which is much shorter than the second time intervals immediately before and after the first time interval.

When evaluating all variants of the embodiment of the patentable method according to the first object of the invention described above, it is necessary to indicate that all these variants of embodiment can be combined in two, three or more, if certain embodiments are not in conflict with each other.

To perform the above tasks in accordance with the first object of the present invention, the installation of vacuum processing contains:

• a vacuum chamber with a reaction zone, and in this chamber:

• a design for creating a plasma discharge, which contains a cathode source of electrons, an anode structure and a holder for the substrate, whereby the cathode source of electrons and the anode structure are functionally interconnected through a power source;

• in addition, in which the anode structure contains a limiter with an internal space open towards the reaction zone, and which contains the anode electrode;

• in which the limiter is installed electrically isolated from the anode electrode;

• the substrate holder is mounted inside the vacuum chamber in such a way as to locate the surface area of the substrate located on the holder, in the immediate vicinity of the limiter hole and substantially closer to this hole than to the cathode electron source, and, in addition, with the ability to functionally connect the substrate with a source of electrical displacement.

The following embodiments of such installations, which can be combined in two, three or more in the absence of mutual contradictions, are described in detail in paragraphs 25-40 of the claims, as part of the present disclosure.

Now the invention is described, in addition, by examples and using the drawings. These drawings demonstrate:

Figure 1 - schematically and simplified, a vacuum processing unit according to the present invention, implementing the manufacturing method according to this invention;

Figure 2 is a schematic perspective view of an embodiment of an anode structure that can be used in the installation of Figure 1;

Figure 3 - heuristically, various forms of change in the discharge current in time, supplied to the plasma discharge electrodes in the embodiment of figure 1 or 2;

Fig. 4a is a schematic illustration of a first type of cathode electron source that is used in the apparatus of the present invention for implementing the method of the present invention;

Fig. 4b is also a schematic illustration of a second type of cathode electron source;

Figure 5 - according to the second object of the present invention, the plasma treatment in a vacuum chamber and preventing damage to the process by undesirable arcing;

6 is still a simplified and schematic, in more detail presented installation for processing of the present invention and the presentation of the production method as an invention, operating in the mode of cleaning by etching;

Fig.7 - the installation and method of Fig.6, carried out in the mode of etching by metal ions;

Fig - installation and method of Fig.6 or Fig.7, carried out in the heating mode of the substrate; and

Fig.9 - installation and method of Fig.6-8, carried out in the mode of coating on the substrate.

Figure 1 demonstrates the principle of a method for manufacturing a clean substrate according to the present invention and produced in a vacuum cleaning unit, as an object of the present invention. A cathode electron source 5 and an anode structure 7 are provided in the vacuum chamber 1, evacuated by a pumping unit 3. The cathode electron source 5 emits electrons into the reaction zone R of the vacuum chamber 1. The anode structure 7 contains an anode electrode 9 and a limiter 11. The limiter 11 defines the boundaries of the internal a space having an opening 13 in the direction of the reaction zone R. In the inner space of the limiter 11, an anode electrode 9 is electrically isolated from the limiter 11. The limiter 11 of otovlen of metal and / or of a dielectric material, in this regard, in one embodiment, at least the interior of the limiter 11 is made of metal. The limiter 11 is at the floating electric potential Φ _fl . For some applications, the limiter can control the supply of a predetermined or adjustable electric potential relative to the wall of the vacuum tank, as shown in FIG. 1 by the dotted line 17. The cathode electron source 5 and the anode electrode 9 are supplied with power from a power source 19, which generates a signal containing a DC component with polarity as shown in FIG.

The electrons generated by the cathode electron source 5 are accelerated by the electric field from the emitting surface of the cathode electron source 5 to the anode electrode 9. Thanks to the limiter 11, which is under the electric potential, different, in any case, from the electric potential of the anode electrode 9, is formed, as schematically shown in figure 1, the increased electron density within the limiter 11 and in the immediate vicinity of its opening 13.

The working gas G _cl , for example argon, krypton, xenon or a mixture thereof, is fed into the vacuum chamber 1 and ionized by collisions with electrons. Whenever a reaction purification is to be performed, a chemically active gas, such as, for example, nitrogen, hydrogen, oxygen, or a mixture thereof, is additionally supplied to chamber 1.

As a result of the increased electron density in the limiter 11 and in the immediate vicinity of its opening 13, an increased degree of ionization of the working gas and, in the case of purification by reaction etching, increased activation of a chemically active gas are formed in the zone under consideration. The substrate 21, the area S of which is to be cleaned, is placed on the holder of the substrate 22 in the immediate vicinity of the hole 13 of the stop 11, aiming the surface S to the hole 13, thereby exposing it in this zone to high-density plasma. It can be said that by means of the limiter 11, the increased plasma density is "focused" on the area S, leading to an increased etching rate, whether reactive or non-reactive etching. The substrate 21 is thus controlled through the holder of the substrate 22 by supplying an electric potential that is negative with respect to the plasma potential. This is achieved, as schematically shown in figure 1, controlled by the supply of negative potential to the holder 22 relative to the electric potential of the wall of the vacuum chamber using a power source 23.

The inner surfaces of the limiter 11, as well as the protective tube 25 for the power supply 15, which is provided for in the embodiment shown in Fig. 1, as part of the limiter 11, are no more than from the anode electrode 9 and from the power supply 15 dark space thickness (DSD) for selected and prevailing operating conditions in the vacuum chamber 1. It should be noted that the power supply tube 25 is electrically isolated from the wall of the vacuum chamber and is under electric potential limit I'm 11.

The internal space of the limiter 11 is U-shaped in cross section relative to the x / y plane, whereby the anode electrode 9 is located near the bottom of the U-shaped, as discussed above, located at a distance from the bottom and from the shoulders of the U-shaped no more than dark space thickness (DSD).

Despite the fact that the design of the electrode 7 can be shaped to have an almost circular hole in area, in one embodiment, as shown in FIG. 2, the anode structure is conceived of elongated, for example, linearly, in the z direction, perpendicular to the x / y plane in figure 1. In this case, the anode electrode 9a also linearly extends, and with it the limiter 11a having a U-shaped profile is extended. In the embodiment of FIG. 2, power is supplied to the anode electrode 9a through a protective tube 25a.

In one configuration, more than one cathode electron source is provided, as schematically shown in FIG. 2 by 5a. In order to achieve a significant increase in the electron density and, accordingly, the plasma density in the limiter 11, 11a and in the immediate vicinity of the corresponding hole 13, 13a, at least 0.5 A / cm should be selected for the discharge current density per unit surface area of the anode electrode ² . In this case, an electric potential drop of approximately 50 V-100 V is formed in the anode dark space at the anode, which leads to high electron acceleration towards the anode electrode with the corresponding ionization effect or, for chemically active gases, the activation effect.

At the very least, an indication that such a drop in the anode electric potential is present is the potential difference between the anode electrode and the chamber wall at about 10 V-85 V.

However, due to such electronic bombardment, the anode electrode receives a heavy thermal load, which requires the adoption of certain measures. In fact, such are the thermal load of the anode electrode 9, 9a and the effectiveness of counter measures, which are crucial for the upper limit of the applied discharge current density. Despite the fact that it seems feasible to provide a system of channels inside the anode electrode 9, 9a and supply a heat-conducting medium through these channels to remove excess heat from the anode electrode, this approach is associated with significant structural complexity and cost.

In order to achieve high plasma densities in combination with the considered high discharge current densities and corresponding high etching rates on the substrate without active cooling of the anode electrode, the power supply 19 is controlled with a DC bias in a pulsed mode. The plasma discharge between the cathode electron source 5, 5a and the anode electrode 9, 9a, which is actually a low-voltage discharge, is thus controlled, as shown in FIG. 3, by a pulsed current superimposed on a DC bias. As shown schematically in FIG. 3, superimposed pulses can be of the same polarity with respect to the direct current bias, can be of both polarities and, in any case, can be of the chosen shape and, accordingly, of the spectrum. In one embodiment, at least one of the parameters can be selected or configured: pulse repetition rate, amplitude of a mono- or bipolar pulse relative to the DC bias value, maximum load and, accordingly, the pulse duration and the shape of the superimposed pulse. Thus, the plasma density can be adjusted near the anode structure, in the limiter 11, 11a and in close proximity to it.

In a further embodiment, as shown in FIG. 1, a low-voltage plasma discharge between the cathode electron source 5 and the anode electrode 9 is controllably shaped by a magnetic field H generated, as shown schematically, by the construction of the inductor 27. By means of such a magnetic field created so as to be controlled by a variable, it becomes possible to control the plasma impedance between the cathode electron source 5 and the anode 9 and, thus, ultimately control the density LASMA, which is subjected to the action area of the substrate S. By means of such a magnetic field H, it thus becomes possible to adjust and change the distribution of the etching rate over the surface area S of the substrate 21 to be cleaned by etching.

So far, we have discussed the cathode source of electrons 5 only as providing a supply of electrons. However, two types of electron cathode sources can be used 5. The first type of electron sources actually emits mainly only electrons, such as a cathode filament or a hollow cathode. Fig. 4a shows in a schematic diagram such a first type of electron source represented by a filament source heated by an incandescent current I. E denotes an electric field applied by a low voltage between the cathode electron source 5 and the anode electrode 9, 9a.

The second type of cathode electron source 5 is a cathode, which additionally emits source material into the reaction zone with electrons. Such sources are, for example, spray sources, including magnetron sputtering sources, sputtering sources in an arc discharge. This type of cathode electron source is schematically represented in FIG. 4b by a magnetron sputtering source. If the substrate made according to the invention should only be cleaned by etching, then cathode sources of electrons of the first type can be used. If, on the other hand, before and / or after cleaning, the substrate must be further treated, that is, covered with a plurality of layers, then it is advantageous to use cathode sources of electrons 5 of the second type.

As shown in FIG. 4b, when using such a cathode electron source 5 of the second type, a controllably movable shutter 29 can be proposed that is moved between the closed position, as shown, blocking the flow of material from the surface of the cathode to the substrate 21 and onto this substrate, and the open position when such a flow becomes possible. In ion etching cleaning mode, the shutter 29 is in the closed position. When cleaning by etching, as previously considered, the only anode that interacts with the cathode source of electrons 5, regardless of its type, is the anode electrode 9, 9a. Using the considered etching technology and, especially, due to the concept of anode design controlled as described, a very high etching rate on the substrate is achieved. In this case, high-density plasma is "focused" on the surface of the substrate. The design of a linearly elongated anode structure, as shown in FIG. 2, and the possible movement of the substrates relative to the anode structure leads to a very good density distribution of the etching rate over the surface of the substrate to be cleaned by etching. The etching effect is uniformly distributed over the surface of the substrate, as well as inside the depressions and on the protruding parts of such a surface. Thus, if the substrate is part of a tool with cutting edges, the result is that such edges are etched equally with areas away from the edges.

Also, when evaluating FIG. 1, it should be noted that for additional adjustment of the etching rate over the area S of the substrate, as well as its thermal load caused by electron and ion bombardment, a bias source 23 is used both with direct current and with direct and alternating current That includes operating with direct current and superimposed mono- or bipolar pulses. Whenever the bias is performed with direct current and superimposed pulses, at least one of the parameters can be configured to optimize the specific effect of spray cleaning on the surface S of the substrate: pulse repetition rate, pulse duration, and at the same time maximum load, mono amplitude or bipolar pulse and pulse shape.

It has been pointed out that a plasma discharge between the cathode electron source 5 and the anode electrode 9, 9a can be called a “low voltage” plasma discharge. Although this term is perfectly understood by experienced operators, it is not clear by definition what “low” means. This is made clear by some of the operating parameters, such as discharge voltage and discharge current, determined from the density of the discharge current and the area of the anode electrode, as follows.

The following are now recommended operating parameters:

• The area of the anode electrode used now, open to the reaction zone

Width W _AN , as shown in FIG. 2 in the y direction: 8 cm.

The length in the z direction in figure 2: 60 cm

W _{AN is} usually determined from the length of the substrate in the Z direction and the allowance along the length from the ends of the anode electrode at both ends of the substrate from 5 cm to 10 cm.

• Cathode electron sources 5a: two sputtering targets in an arc discharge.

• Discharge current between each of the targets and the anode electrode: 200 A, resulting in a current density on the open surface of the anode electrode of 9a 0.83 A / cm ² .

• Limiter

The length of W _co bottom of the form U: 8 cm + 2 x DSD.

U-shaped shoulder length L: 0.5 W _AN -1.5 W _AN .

Located at a floating electric potential.

The distance d between the hole of the stopper 13 and the substrate area S (see figure 1):

2 cm ≤ d ≤ 10 cm, preferably

4 cm ≤ d ≤ 6 cm.

By varying the length L of the arms of the limiter U, the distribution of the etching rate can be adjusted.

• Etching gases

Working gases: argon, krypton, xenon or mixtures thereof.

Gases for reactive etching: nitrogen, hydrogen, oxygen or mixtures thereof.

• Total operating pressure

0.1 Pa-10 Pa, preferably 0.1 Pa-3 Pa (including all limits).

• Low-voltage discharge voltage U _AC between the cathode electron source and the anode electrode:

20 V ≤ U _AC ≤ 100 V, preferably

35 V ≤ U _AC ≤ 70 V,

which leads to a potential difference between the anode electrode and the wall of the vacuum chamber from 10 to 85 V, while, in the preferred process, from 20 to 50 V.

• Pulse repetition rate f: 0.2 Hz ≤ f ≤ 200 KHz.

• A magnetic field H set to control the distribution of etching on the substrate and / or to control the plasma impedance and, in particular, the processing speed at a given discharge voltage U _AC .

• Substrate electrical displacement: from 10 V to 2000 V DC, more specifically:

- for cleaning by etching 60 V-1000 V,

- for etching with metal ions 600 V-2000 V,

- for coating 10 V-300 V,

while superimposed pulses with a frequency of from 0 Hz to 500 Hz, preferably in this case, in the frequency range from 50 Hz to 300 Hz.

Still described in the first aspect of the present invention are the manufacture of peeled substrates and an apparatus for performing such a treatment.

5, a second aspect of the present invention is described which is patentable per se, but which can be optimally combined with the production of peeled substrates, as described above for the first aspect.

5, this second object is presented in the most generalized form. To create a plasma discharge inside the vacuum chamber 100, a pair of plasma electrode electrodes 102 and 104 is controlled by an electric power source 110. In general, one of the electrodes 102, 104 can be, for example, an ion sputter cathode, an arc sputter cathode, a hollow cathode, or a direct thermoelectronic cathode. glow, etc. The designations "cathode" and "anode", again, upon general consideration, can be rather vague or determined only by the corresponding ratio of the etching process to the sputtering process in the corresponding areas of the electrode, if the electrode pair is supplied with alternating current, especially in the high-frequency mode. Accordingly, at least part of the wall of the vacuum chamber can serve as one or even both electrodes, as is well understood by an experienced operator, for example, when considering a high-frequency etching chamber.

A substrate 106 is prepared for processing, and in the vacuum chamber 100, voltage is supplied to it from a bias source. The substrate, however, in a general aspect, can be placed on one of the electrodes 102 and 104, which is also well known to the experienced operator.

In such a conventional processing process, it is necessary to provide for an undesirable arcing process that can occur between the electrodes 102 and 104, such as between the anode and the ion sputter target, or between any of the electrodes 102 and 104 and the substrate 106. It is clear that when the electrodes 102 and 104 are concurrently determined for the source of vaporization in an arc discharge, then arcing between these electrodes is a desirable process, but not arcing between any of these electrodes and the substrate 106.

In a second aspect of the present invention, technological defects caused by undesired arcing are prevented. This is achieved by switching that of the electrodes 102 or 104, which is involved in the process of unwanted arcing, on the corresponding auxiliary electrode. Thus, according to FIG. 5, an auxiliary electrode _AUX 102 is proposed, for example. Using the switching unit T, the power source of the discharge 110 is switched from the electrode 102 to the auxiliary electrode 102 _AUX . This is done either regularly, for example periodically, during the plasma treatment of the substrate 106 in order to prevent said arcing, or as soon as the onset of arcing is detected, then the power supply 110 is switched off. In any case, the functioning of the processing electrode, such as electrode 102, is replaced by the connection of the corresponding auxiliary electrode, such as _AUX electrode 102, for the first short time period, significantly shorter than the second processing time intervals before and after the first time periods. Arcing between the electrodes 102 and 104 can be detected, as is known to an experienced operator, for example, by monitoring the discharge current in the power circuit 112.

Thus, the essence of the development and the subject of a special application is that the electrodes are switched to the auxiliary electrode. For example, in the case of two electrodes 102 and 104, used as an ion sputtering target, and an anode of a corresponding ion sputtering source, an auxiliary cathode is proposed rather than an auxiliary anode. Referring to FIG. 5, if a disturbing arcing is formed between one of the two electrodes 102 and 104 on the one hand and the substrate 106 on the other, by monitoring the circuit current through an analysis of the polarity of the inrush current bias 114, one can detect which of the electrodes 102, 104 is involved in the arcing on the backing. In this case, the corresponding electrode involved, 102 or 104, is switched to its auxiliary partner.

Departing from the basic concept of the present invention in its second aspect, which was explained using FIG. 5, let us go back to FIG. 1, which until now has only been explained in the context of the first aspect of the invention, which is etching cleaning.

It is quite clear that the prevention of processing defects due to undesired arcing, as broadly explained in the context of FIG. 5, can be well suited for use in an embodiment as explained in the context of FIG. 1.

Therefore, and according to FIG. 1, an auxiliary anode 9 _{AUX is} provided near the cathode electron source 5, which is intended, for example, as a ring anode. Each time, if it is necessary to prevent or interrupt the arcing, using the switching unit T, the anode 9 is disconnected and replaced with the auxiliary anode 9 _AUX . The operation of the switching unit T is provided either by a timer from the time relay 30 or by triggering upon detection of an arc of the trigger circuit. Arc detection is carried out, for example, by monitoring the current in the substrate bias circuit using the sensor unit 32, as shown schematically. The output signal of block 32 starts, for example, a block of a single or multi-pulse generator 34, which makes it possible to preferably control the duration of the pulse. Thus, the switching unit T is controlled either by a time relay 30, or by means of a pulse generator unit 34, or by both, as shown schematically by the “and / or” link in FIG. Thus, the prevention of the arc can be carried out, for example, under the control of the time relay 30, and the arc detector can be used as emergency control if, despite the control by the timer 30, an arc has formed.

Thus, the general approach to the issue of arc prevention, as explained in FIG. 5, is excellent for use in combination with a cleaning method, as explained in the context of FIGS. 1-4.

Figure 6 presents a vacuum installation for processing a variety of tool parts as substrates. The installation, as schematically shown in FIG. 6, is one embodiment implemented in accordance with the embodiment of FIGS. 1 or 2 for the considered special types of substrates. The installation includes an arc control method, as explained using FIG. 5 and FIG. 1.

To facilitate comparison of the embodiment of FIG. 6 with the embodiment of FIG. 1, the same reference numbers are used for similar nodes.

In a vacuum chamber 1 with a pumping channel 3a, a cathode electron source 5 is provided that is configured as an evaporation target in an arc discharge 6. Instead of it, for example, a thermionic cathode or an ion sputter cathode target, in general, a second type electron cathode source described above can be proposed. .

The anode structure 7 comprises an anode electrode 9 or 9a, as well as a limiter 11 or 11a. The limiter 11, 11a is made of metal and is at a floating electric potential.

The limiter 11, 11a sets the shape of the corresponding hole 13, 13a. Power is supplied from the power supply 19 through the power supply circuit 15 and the switching unit T1, as well as through the switching unit T2 to the anode electrode 9, 9a relative to the cathode evaporation target in the arc discharge 6. The substrates 21a are mounted on the carousel holder of the substrates 22, rotatable around the axis M electric drive 24. On the substrate 21a - the cutting parts of the tools located on the carousel 22, through the switching unit T3 and the power supply unit for applying an electric bias 23, a certain electric potential is supplied.

The magnetic field H is generated by the construction of the inductor 27. The cathode ion sputtering target 6 is fenced off from the substrates 21a located on the carousel 22, controlled by a movable shutter 29 (see FIG. 4b). Near the cathode evaporation target in arc discharge 6, an auxiliary anode 9 _{AUX is} proposed. As for the geometric dimensions and operating parameters, the above is considered in the context of the embodiment of FIG. 1. The embodiment of FIG. 6 can be operated in various modes of operation, which will be explained later. The operating mode shown in FIG. 6 is an etching cleaning mode, whereby the working gas and possibly the reactive gas are supplied to the vacuum chamber 1 through the corresponding gas inlet ports G _Cl . In the etching cleaning mode, the anode electrode 9, 9a is functionally connected through the switching unit T1 and the switch T2 to the positive pole of the power supply 19, the negative pole of which is functionally connected to the cathode sputtering target in the arc discharge 6. The carousel holder of the substrates 22 and with it the substrates 21a are functionally connected to the negative pole of the bias source 23 through a switching unit T3, the positive pole of which is connected to the wall of the vacuum reservoir 1. Operationally movable shutter 29, which It is controlled by a suitable drive (not shown), closed, blocking the path of the sprayed material from the cathode ion spray source 6 to the substrates 21a located on the rotating carousel 22.

In such an operating mode, in which a low-voltage plasma discharge is created between the cathode target of evaporation in the arc discharge 6, acting as an electron source, and the anode electrode 9, 9a, the substrates 21a on the rotating carousel 22 are etched by working gas ions or, possibly, an activated chemically active gas as described in the context of FIG. Arc detection or, more generally, arc protection, is performed, as explained in the context of FIG. 1, by blocks 30, 34, by the detection unit 32, thereby introducing the switching unit T1 in the course of time, for example periodically, and / or each time when the sensor unit 32 detects the onset of arcing. Through this control, the switching unit T1, by analogy with the switching unit T in FIG. 1, connects the operation of the auxiliary anode 9 _AUX relative to the cathode evaporation target in the arc discharge 6 instead of the functioning of the anode electrode 9, 9a.

Fig. 7 shows an embodiment as described in the context of Fig. 6, operated in a second mode of operation — etching or purification by metal ions.

In this case, the shutter 29 is partially open so that metal particles or ions from the metal cathode spraying target in the discharge of the arc 6 reach the surface of the substrates. Thus, due to the impact of metal ions, the substrates 21a are further etched on the rotating carousel 22. The arc protection is carried out in the same way as explained in the context of FIG. 6.

Fig. 8 illustrates the embodiment of Fig. 6, operated in a third mode, a heating mode. Using the switching unit T2, the operation of the anode electrode 9, 9a is stopped and the substrates 21a located on the rotating carousel 22 are switched via the switching units T3 and T2 to the positive pole of the power supply 19, transferring them to the position of the anodes relative to the cathode sputtering target in the arc discharge 6. Gate 29 is closed. In this case, the substrates 21a are heated by electronic bombardment. The heating rate is controlled by the appropriate setting of the power source 19. Arc protection can be disabled.

Fig. 9 shows the same embodiment as in Fig. 6, operated in the mode of coating the substrates. In this case, the cathode sputtering target in the arc discharge 6 is used as part of a normal sputtering source, where the wall of the vacuum reservoir 1 plays the role of the anode. This option is implemented using switching units T5 and T2. The anode electrode 9, 9a, previously operating in the modes of cleaning by etching or cleaning by etching with metal ions as an anode relative to the cathode sputtering target in the arc discharge 6, is disabled.

Whenever, for the purpose of arc protection, the auxiliary anode is activated, it is desirable if possible that such auxiliary _AUX anode 9 operates relative to the cathode at an electric potential different from the electric potential which is supplied to the standard anode 9, 9a. As shown in FIG. 6 by the dashed line, this can be realized using an auxiliary 19 _AUX power supply.

Claims (44)

1. A method of manufacturing at least one purified substrate or substrate obtained as a result of cleaning and further processing before and / or after such cleaning, comprising: creating in a vacuum chamber having a reaction zone and containing a gas intended for ionization, at least one plasma discharge, between at least one cathode source of electrons and at least one anode structure containing at least one anode electrode, an increase in electron density, and thereby density directly adjacent to said at least one anode structure by means of a limiter having an opening open towards the reaction zone and containing at least one anode electrode, providing said anode electrode inside said limiter and exposing said limiter to electric potential different from the electric potential applied to said anode electrode, thereby concentrating the increased ion density in said boundary Itel and in the immediate vicinity of the aforementioned hole, the placement of the aforementioned substrate with the supply to it of a negative electric potential, at least averaged over time, relative to the aforementioned electric potential of the anode electrode, the placement of at least the surface of the aforementioned substrate for a predetermined time cleaning under the influence of the mentioned region of increased ion density and in the immediate vicinity of the aforementioned holes, thereby, significantly closer to -mentioned opening than to said electron source cathode. 2. The method according to claim 1, in which the aforementioned plasma discharge is selected as a low voltage discharge with a voltage U _AC between the anode electrode and the cathode electron source, the value of which is:
20 V≤U _AC ≤100 V, preferably
35 V≤U _AC ≤70 V. 3. The method according to claim 1, in which the joint anodic voltage is supplied to said anode electrode and said cathode source of electrons by means of an electric power circuit with floating electric potentials. 4. The method according to claim 2, in which the joint anodic voltage is supplied to said anode electrode and said cathode source of electrons by means of an electric power circuit with floating electric potentials. 5. The method according to one of claims 1 to 4, comprising the operation of said limiter on a floating electric potential. 6. The method according to claim 1, in which the inner space of the said limiter is selected, essentially U-shaped, in at least one plane of section, and said anode electrode is located at a distance from the bottom and along the bottom of said U- figurative internal space, considered in the mentioned section plane. 7. The method according to claim 6, in which said inner space is selected in the form of a groove perpendicular to said section plane. 8. The method according to claim 1, containing power to said anode electrode relative to said cathode electron source in the presence of direct current and superimposed pulses. 9. The method of claim 8, in which at least one of the direct current values, the amplitude of said pulses relative to the magnitude of said direct current, pulse repetition rate, pulse duration or maximum load, pulse shape are adjustable. 10. The method according to one of claims 6 or 7, in which the repetition rate f of said pulses is selected
0.2 Hz <f≤200 kHz. 11. The method according to claim 1, in which the inner space of the said limiter is selected, essentially U-shaped, in at least one plane of section, and said anode electrode is located at a distance from the bottom and along the bottom of said U- shaped inner space, considered in the said plane of cross-section, wherein said anode in said plane has a length of W _AN , said bottom of said inner space of said limiter is selected with a length of W _C0 in compliance with relationships:
W _AN <W _CO <W _AN + 2DSD,
where DSD is the thickness of the dark space under the operating conditions of said method in said vacuum chamber. 12. The method according to claim 1, in which the inner space of the said limiter is selected, essentially U-shaped, in at least one plane of section, and the said anode electrode located at a distance from the bottom and along the bottom of said U- shaped inner space, considered in the said plane of cross-section, wherein said anode in said plan has a length W _AN , the shoulders of said internal U-shaped space of said limiter have a length L in compliance with the relation :
0.5 W _AN ≤L≤1.5 W _AN . 13. The method according to claim 1, comprising exposing the surface of said substrate to be cleaned at a distance d from a plane defined by said opening, which is selected:
2 cm ≤d≤10 cm. 14. The method according to claim 1, further comprising supplying said electrical anode to said anode relative to said cathode electron source to create a current density per unit area of the anode electrode of at least 0.5 A / cm ² . 15. The method according to claim 1, further comprising creating a drop in the anode potential of 50 to 100 V, including both limits. 16. The method according to claim 1, comprising creating a potential difference between 10 and 85 V between the anode electrode and the wall of the vacuum chamber, including both limits. 17. The method according to claim 1, in which the said at least one cathode source of electrons emits essentially only electrons. 18. The method according to claim 1, wherein said cathodic electron source is selected as the cathode emitting electrons and the target material, and wherein coating the substrate from the material source is prevented by a shutter. 19. The method according to claim 1, in which the DC bias potential, a combination of direct and alternating current or alternating current, and preferably a direct current potential with superimposed pulses, are applied to said substrate. 20. The method according to one of claims 1 to 4, 6-9, 11-19, in which the aforementioned substrate is subjected to additional processing, at least one of the following technological operations: cleaning by etching with metal ions: wherein said cathode source is selected electrons to emit electrons and the metal of the source, and only partially preventing the flow of metal particles from said cathode to said anode electrode, heating: in this case, said anode electrode is turned off and the said substrate is operated as an anode electrode regarding said cathodic electron source, coating. 21. The method according to claim 5, in which the aforementioned substrate is subjected to further processing, at least one of the following technological operations: cleaning by metal ion etching: wherein said cathode electron source is selected for emitting electrons and the source metal, and only partially preventing the flow of metal particles from said cathode to said anode electrode, heating: in this case, said anode electrode is turned off and the aforementioned substrate is operated as an anode electrode relative to said utogo cathode electron source, the coating application. 22. The method according to one of claims 1 to 4, 6-9, 11-19, further comprising providing an auxiliary anode electrode in said vacuum chamber, and preventing the existence and development of arc burning by disabling the functioning of the anode electrode, which is active during the process processing the substrate for the time of the first time interval, and connecting to the operation of said auxiliary anode electrode for said first time interval, wherein said first time interval is shorter than the second approx time immediately before and after said first period of time. 23. The method according to claim 22, wherein said anode electrode that is active during the substrate processing process selects an anode electrode of said anode structure, and said auxiliary electrode is arranged substantially closer to said cathode electron source than to said anode structure. 24. The method according to item 22, in which said replacement of the operation of said anode electrode active during said processing process by the operation of said auxiliary anode electrode is controlled in at least one of the following modes: prevention mode, repeated in time, controlled timer, restriction mode, controlled by the detection of arcing. 25. Installation of a vacuum treatment, designed to implement a method of manufacturing at least one cleaned substrate or substrate obtained as a result of cleaning and additional processing, comprising: a vacuum chamber with a reaction zone and in said chamber: a plasma discharge structure containing a cathode source electrons, an anode structure and a substrate holder, said electron cathode source and anode electrode of said anode structure being functionally interconnected through and a power source, said anode structure comprising a limiter with an internal space towards said reaction zone and comprising said anode electrode, said limiter mounted insulated from said anode electrode, said substrate holder mounted inside the vacuum chamber so as to position the surface of the substrate on said holder near said hole and much closer to said hole than to said cathode source of elec tron, and, furthermore, which is such that said substrate is operatively connected to a source of electrical bias. 26. The apparatus of claim 25, wherein said anode electrode, said cathode electron source, and an electrical circuit comprising said power source and functionally interconnected said anode electrode and said cathode electron source are electrically floating. 27. The apparatus of claim 25, wherein said limiter is connected to a bias supply source to the limiter and is mounted electrically floating. 28. The apparatus of claim 26, wherein said limiter is connected to a bias supply source to the limiter and is mounted electrically floating. 29. Installation according to one of paragraphs.25-27, in which the inner space of the said limiter has a mainly U-shape in at least one section plane, and where said anode electrode is mounted at a distance from the bottom and along the bottom said U-shaped inner space viewed in said section plane. 30. The installation according to clause 29, in which said inner space has the shape of a groove perpendicular to said section plane. 31. The apparatus of claim 25, wherein said power source is a source that generates direct current with superimposed pulses at the output. 32. The apparatus of claim 25, wherein the interior of said limiter is generally U-shaped in at least one section plane, said anode electrode being spaced from the bottom and along the bottom of said U-shaped interior, in said plane of section, wherein said anode in said plane has a length of W _AN , said bottom of said inner space of said limiter is selected by length of W _CO , in compliance with the ratio:
W _AN <W _CO ≤W _AN + 2DSD,
where DSD is the thickness of the dark space in the conditions in which the installation is intended for operation. 33. The apparatus of claim 25, wherein the interior of said limiter is substantially U-shaped in at least one section plane and said anode electrode is mounted at a distance from the bottom and along the bottom of said U-shaped interior considered in the said section plane, said anode in the said plan has a length W _AN , the shoulders of said internal U-shaped space of said limiter have a length L, subject to the ratio:
0.5 W _AN ≤L≤1.5 W _AN 34. The apparatus of claim 25, wherein said substrate holder is mounted inside said vacuum chamber so as to position said surface region at a distance d from a plane defined by said hole, and wherein the ratio is:
2 cm ≤d≤10 cm. 35. The apparatus of claim 25, wherein said at least one cathode electron source emits mainly only electrons. 36. The apparatus of claim 35, wherein said cathodic electron source is either a direct glow cathode or a hollow cathode. 37. The apparatus of claim 25, wherein said cathode source emits electrons and source material in the direction of said reaction zone and furthermore comprises a movable shutter between said cathode electron source and said workpiece holder, wherein the shutter is driven from a closed position, closing the emitting surface of said cathode, to an open position, being away from said surface and said cathode. 38. The apparatus of claim 37, wherein said cathode electron source is a target for ion sputtering or vaporization in an arc discharge. 39. The installation according to one of paragraphs.25-28, 31-38, which is an etching cleaning installation, said etching cleaning installation additionally operating in the following operating modes: a metal ion etching cleaning mode in which said cathode electron source emits electrons and the source metal and is only partially covered by a shutter which is located between the emitting surface of said cathode and said substrate holder, a heating mode in which said anode electrode is disconnected is connected to said power source, and said substrate holder, like an anode, is operatively connected to said cathode electron source through said power source, a coating mode. 40. The installation according to clause 29, which is an etching cleaning installation, said etching cleaning installation additionally operating in the following operating modes: a metal ion etching cleaning mode in which said cathode electron source emits electrons and a source metal and is only partially covered by a shutter which is located between the emitting surface of said cathode and said substrate holder, a heating mode in which said anode electrode is disconnected from said about the power source, and said substrate holder, like the anode, is functionally connected to said cathode electron source through said power source, the coating mode. 41. The apparatus of claim 30, which is an etching treatment unit, said etching treatment unit additionally operating in the following operating modes: a metal ion etching cleaning mode, wherein said cathode electron source emits electrons and a source metal and is only partially covered by a shutter which is located between the emitting surface of said cathode and said substrate holder, a heating mode in which said anode electrode is disconnected from said about the power source, and said substrate holder, like the anode, is functionally connected to said cathode electron source through said power source, the coating mode. 42. The apparatus of claim 25, further comprising an auxiliary anode electrode and a switching control unit in said vacuum chamber that connects the operation of said auxiliary electrode instead of said anode electrode for a first time interval that is significantly shorter than time intervals immediately before and after said first time interval . 43. The apparatus of claim 42, wherein said auxiliary electrode is placed much closer to said cathode electron source than to said anode structure. 44. The apparatus of claim 42 or 43, wherein said switching device has a control input signal operatively coupled to at least one of the output signals of a timer or an arc start detector.

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