WO2012025249A1 - Method and control device for cleaning a plasma treatment device and/or a substrate accommodated in a plasma treatment device - Google Patents

Abstract

The invention relates to a method for cleaning a plasma treatment device and/or a substrate accommodated in a plasma treatment device, wherein the plasma treatment device comprises at least two plasma units, wherein at least two of the plasma units are sequentially ignited in order to produce a plasma wave that progresses through the plasma treatment device. Alternatively, a pulsing plasma pressure wave is produced by means of at least one plasma unit.

Description

 1 HQD-28423

Method and control device for cleaning a plasma treatment device and / or a substrate accommodated in a plasma treatment device

The present invention relates to a method for cleaning a plasma treatment apparatus and / or a substrate accommodated in a plasma treatment apparatus and a control apparatus for carrying out this method.

It is known to treat substrates by means of a plasma. In particular, in semiconductor technology, it is known to etch a surface of a substrate by means of a plasma or to support the buildup of layers on the substrate by means of the plasma. For example, it is known to grow a SiO _x N _y film by means of a plasma-assisted oxidation or to support deposition from the vapor phase by means of a plasma (PECVD = Plasma Enhanced Chemical Vapor Deposition).

For the treatment of the substrates plasma treatment devices are provided, in which plasma units are provided, which serve to generate the plasma. Since in the field of substrate processing, in particular in the field of semiconductor technology, even small impurities on the substrate or impurities in the layers grown on the substrate lead to unusability of the respective product, it is essential to keep both the plasma treatment apparatus and the substrate itself as particle-free as possible ,

In the plasma treatment apparatus, the substrate is usually accommodated in a plasma chamber, in which the actual plasma treatment, ie, for example, plasma etching or plasma-assisted deposition of a film, takes place. Such a device for treating substrates by means of a plasma is known, for example, from DE 10 2008 036 766 A1. 2 HQD-28423

In order to be able to achieve a cleaning of the plasma treatment device and / or a substrate accommodated in the plasma treatment device, rinsing methods are known, by means of which process gas or another gas, for example an inert gas, is passed through the respective process chamber and the substrate to remove impurities from the process chamber or rinse off from the substrate.

Impurities on the substrate may occur, for example, due to mechanical damage during handling of the substrate (in pre-process steps or during the treatment), thermal expansion of the substrate, or rotation of the substrate in the process chamber. Particles may adhere to the process chamber wall or to the substrate due to coulomb electrical forces, which may be generated in particular by frictional forces between the particles and convection-bearing ambient gases. These forces can occur, for example, due to thermophoretic and / or photophoretic effects, convection or radiation pressure. Furthermore, particles can be transported and deposited on the chamber wall of the process chamber or on the substrate by gravity, diffusion or by a plasma wave which is generated during the switching on and off of the plasma for the treatment of the respective substrate. Accordingly, unwanted particles can sediment on the chamber wall or the substrate. It is an object of the present invention to further improve the cleaning of both the plasma processing apparatus and, in particular, the process chamber in the plasma processing apparatus and the cleaning of a substrate accommodated in the plasma processing apparatus. This object is achieved by a method according to claim 1 and an apparatus according to claim 13. Further embodiments of the invention will become apparent from the dependent claims. 3 HQD-28423

In the method of cleaning a plasma processing apparatus and / or a substrate accommodated in a plasma processing apparatus, the plasma processing apparatus comprises at least two plasma units, wherein according to the present invention, at least two plasma units are sequentially ignited to generate a plasma wave progressing through the plasma processing apparatus.

By providing a plasma wave (or pressure wave, respectively) progressing through the plasma processing apparatus, particles which are present on the substrate, the chamber wall or other parts of the plasma processing apparatus can be dissolved. For example, the plasma field neutralizes the coulombic charges through which the particles adhere to the substrate surface or chamber walls of the process chamber. The resulting by the application of the plasma wave pressure fluctuations within the process chamber further solve weakly bound particles from the chamber wall or the substrate. Accordingly, according to the method according to the invention, particles which were not accessible to a simple gas purging process can be removed from the process chamber or from the substrate surface in this way, since they are detached from the respective surfaces.

As a result of the plasma wave progressing in the plasma treatment apparatus, the resulting forces remove the particles from the chamber interior surface as well as from the substrate surface. As an alternative to sequential ignition, removal of the particles from the interior surfaces of the chamber can also be achieved by already pure pulsing (simultaneous ignition of the plasma units) of the plasma (pressure wave).

Preferably, at least three plasma units are provided in the plasma processing apparatus, which are ignited sequentially such that a directional plasma wave propagates through the plasma processing apparatus. Preferably, this plasma wave travels in the plasma processing apparatus from one side of the process chamber to the 4 HQD-28423 other side, for example from left to right or from right to left or from top to bottom or vice versa. In this way, the entire plasma processing apparatus can be traversed by means of the plasma wave at least in the area relevant to the substrate processing such that the particles which have been released by the plasma wave are driven in one direction. Here they can preferably be collected, for example by suction. Preferably, the plasma wave covers the substrate and / or the chamber walls and in a process chamber without a substrate, only the chamber walls.

Preferably, at least three plasma units are provided in the plasma treatment apparatus and are ignited in such a way that two plasma waves simultaneously run in opposite directions. In this case, the plasma waves preferably run symmetrically and particularly preferably outwards from the center of the plasma treatment device, in order to transport dissolved particles away from the surface relevant for the substrate treatment. Preferably, the particles can be removed by suction at the edges.

In order to achieve effective cleaning of the plasma processing apparatus and / or a substrate accommodated in the plasma processing apparatus, the plasma units may be repetitively sequentially ignited so that plasma waves repeatedly successively pass through the plasma processing apparatus, particularly 2 to 10,000 plasma waves in succession. By repeatedly applying the plasma wave to the plasma treatment apparatus, a more effective cleaning is performed such that the particles adhered to the respective surfaces are better dissolved and better transported.

Preferably, the plasma devices with different powers are ignited in such a way that plasma waves of different intensity pass through the plasma treatment device. Of course, the successive plasma waves can also be ignited with the same power of the plasma units, ie with the same intensity. The provision However, HQD-28423 of different intensities has the advantage that differently bound particles can be correspondingly detached from the surfaces. Preferably, a pressure change of the interior pressure in the plasma processing apparatus is applied simultaneously with the generation of the plasma wave. This pressure change can be achieved, for example, by pumping or rinsing the process chamber by means of an inert purge gas or by means of process gas. Such a pressure change may be performed, for example, from 100 mTorr to 1 Torr or more. As a result of the pressure change carried out simultaneously with the plasma wave, the particles dissolved by the plasma wave can be further detached from the surfaces by means of the gas flow resulting from the pressure change and then removed, preferably into a suction device. In this case, the purge gas is preferably introduced at the starting point of the plasma wave and the suction takes place in the direction of movement of the shaft, that is, for example, in an edge region of the process chamber.

For the sequential ignition of the plasma units, an ignition power is preferably introduced into at least one first plasma unit (master) in order thereby to generate a plasma in a first plasma region. Then a power is fed into at least one second plasma unit (slave), wherein the power is substantially smaller than the ignition power of the second plasma unit. The first plasma region overlaps with a radiation region of the second plasma unit, so that the plasma in the plasma region of the second plasma unit can be ignited by means of the already ignited plasma in the first plasma region. In this way, a plasma wave progressing through the plasma treatment apparatus can be produced in a simple manner and rapidly and successively switchable, in particular if the plasma regions of all adjacent plasma units overlap one another. In this way it becomes possible to generate a progressive plasma wave in the process chamber with relatively low power in the plasma devices. Regarding 6 HQD-28423 the special ignition and arrangement of the plasma devices is here referred to the non-prepublished DE 10 2010 035 593 of the applicant, which is insofar made the subject of the present application. The generation of the plasma wave is preferably coordinated with the application of the pressure change in the plasma processing apparatus.

The invention further advantageously relates to a control device for carrying out the method described above, wherein the control device can individually control at least two plasma units in a plasma treatment device in order to be able to generate a plasma wave progressing through the plasma treatment device.

The device is provided in particular together with a process chamber in a plasma treatment device and at least two plasma units. Furthermore, the control device is advantageously connected to means for applying a pressure change in a process chamber of a plasma treatment apparatus. A plasma processing apparatus according to the present invention includes a control device for individually controlling the plasma devices such that at least two plasma units are arranged adjacent to each other so that their radiation area overlaps and the controller sequentially controls the plasma units to generate a plasma wave advancing through the plasma processing apparatus ,

The invention will be explained in more detail with reference to the drawings; in the drawings shows:

Figure 1 is a schematic sectional view through a plasma treatment apparatus; EP2011 / 004311

7 HQD-28423

FIG. 2 shows a schematic cross-sectional view of the plasma treatment device according to FIG. 1 with a cutting plane rotated by 90 degrees;

 Figure 3a is a schematic bottom view of an arrangement of

 Plasma units that can be used in the arrangement according to Figures 1 and 2;

 Figure 3b is a schematic view from below of an alternative

 Arrangement of plasma units that can be used in the arrangement according to Figures 1 and 2

 Figure 4 is a schematic view from below of an alternative

 Arrangement of plasma units that could be used in the device according to Figures 1 and 2;

 Figure 5 is a schematic plan view of different arrangement examples for plasma units, which could be used in the apparatus according to Figures 1 and 2; and

 Figure 6 is a schematic representation of a control device for

 Control of a plasma treatment device to perform the procedure for cleaning.

Location or directional information used in the following descriptions refers primarily to the illustration in the drawings and therefore should not be taken as limiting. You can also refer to a preferred final arrangement.

Figures 1 and 2 show each rotated by 90 degrees cross-sectional views through a plasma treatment apparatus 1 for the treatment of sheet-like substrates 2. The substrates 2 may be in particular semiconductor substrates whose surface is etched by means of a plasma or on the surface of which a layer growth is performed. The plasma treatment device essentially consists of a housing 3, which defines a process chamber 4 in the interior, a substrate receiving unit 7, an optional heating arrangement 8 and a plasma arrangement 9. 8 HQD-28423

The housing 3 may be of any suitable type defining a process chamber 4 in the interior in which predetermined process conditions regarding gas composition and gas pressures can be set via desired inlets and outlets, not shown in the figures. In a side wall of the housing 3, a loading-unloading opening 12 is provided, which can be closed and opened via a movable door element 13. Further, the housing 3 has in opposite side walls a plurality of through holes 14 for receiving cladding tubes 16, which in turn serve to accommodate heating units or plasma units, as will be explained in more detail below. The holes 14 are each formed in pairs in opposite side walls such that a cladding tube 14 may extend through the process chamber 4 through, perpendicular to the holes 14 having side walls. In a lower region of the process chamber 14, eight such pairs of holes 14 are provided with the corresponding cladding tubes 16 received therein. In an upper region, a total of ten pairs of bores 14 are formed in the opposite side walls of the housing 3. Thereby, nine of these pairs are in one line, while another pair are down, i. is offset towards the center of the process chamber. Also in these holes cladding tubes 16 are added.

On an upper wall of the housing 3, a cover element 18 is provided on the inside, ie within the process chamber 4, in order to protect the housing inner wall against a plasma generated by the plasma arrangement 9. Alternatively or additionally, a separating element between the plasma assembly 9 and the substrate 2 may be arranged. Further covering or separating elements may be located in the interior of the process chamber 4. 9 HQD-28423

In the bottom of the housing 3, a through opening for a support shaft 20 of the substrate holding assembly 7 is provided. The substrate holding assembly consists essentially of a vertically extending support shaft 20, a horizontally extending support plate 21, and support members 22. The support shaft 20 extends through the bottom of the housing 3 and may be connected to a drive motor outside the housing 3, for example Rotate support shaft about its longitudinal axis and / or move in the vertical direction. In order to enable a gas-tight passage of the support shaft 20 through the housing 3, corresponding sealing mechanisms, such as a bellows mechanism may be provided in the region of the passage. The support shaft 20 may be constructed, for example, of a material substantially transparent to electromagnetic radiation of the heating arrangement 8, such as quartz. Alternatively, however, the support shaft 20 could also have a highly reflective surface.

The support shaft 20 carries at its upper end the support plate 21, which is vertically adjustable on the support shaft both in the vertical direction, and about a longitudinal axis of the support shaft 20 is rotatable. The support plate 21 is preferably constructed of a material substantially transparent to the electromagnetic radiation of the heating arrangement 8. On an upper side of the support plate 21, a plurality of the support elements 22 is provided, which in turn is constructed of a preferably transparent to the radiation of the heating assembly 8 material. The support elements 22 are shown as conical tapered cone, on the top of the substrate 2 rests. The support elements 22 keep the substrate 2 at a certain distance spaced from the support plate 21st Overall, the substrate-holding arrangement could also have a different structure. In particular, the support plate could be constructed as a so-called susceptor, which has a projection surface corresponding to the substrate 2, and absorbs the electromagnetic radiation of the heating assembly 8 to be heated itself and above the substrate 2 to heat. 10 HQD-28423

The heating arrangement 8 consists essentially of eight heating lamps 24, which are arranged in the eight sheaths 16 in the lower region of the process chamber 4. The heating lamps 24 are designed as flashlights which extend substantially completely through the process chamber 4. The heating lamps 24 may be of any type suitable for heating the substrate 2 by electromagnetic radiation, such as tungsten-halogen lamps. Although not shown in detail, the cladding tubes 16 may be traversed by a cooling medium, such as air, to cool the cladding tubes 16 and the heating lamps 24 during operation. Of course, another heating arrangement may be used, such as a resistance heating arrangement, for example integrated in the support plate.

However, an alternative construction of the heating arrangement 8 is conceivable in which, for example, an arrangement of heating lamps 24 is separated via a quartz plate with respect to a process space for the substrate 2, as is known in the art.

The plasma arrangement 9 consists essentially of a first rod-shaped plasma unit 27 and a multiplicity of second rod-shaped plasma units 28. The first and second plasma units 27, 28 are respectively accommodated in corresponding cladding tubes 6, for example made of quartz, which are located in the upper region of the Process chamber 4 extend therethrough. While the second plasma units 28 are received in the in-line sheath tubes 16, the plasma unit 27 is located in the slightly downwardly shrouded tube 16 (see right outer sheath 16 in Figure 2).

The plasma units 27 and 28 can each have essentially the same basic structure as described, for example, in DE 10 2008 036 766 A1. The plasma units each have an outer conductor 30 and an inner conductor 31. The outer conductor 30 has, as can be seen in the view from below according to the figures 3a and 3b, a portion in T / EP2011 / 004311

1 1 HQD-28423 he completely surrounds the inner conductor 31, and a subsequent slotted region in which the inner conductor is gradually exposed until a free end of the inner conductor is completely exposed. The plasma units 27 and 28 are each of the type which is energized from one side (right, see FIG. 1). At the free end of the inner conductor 31 of the first plasma unit 27, a resonator 32 (see Figure 3) is further provided to promote ignition of a plasma in the region of the first plasma unit. Such a resonator may also be mounted on the second plasma units 28.

For the exact structure of the plasma units, reference is made to DE 10 2008 036 766 A1, which is therefore the subject of the present invention in order to avoid repetition. The plasma units can be accommodated in one or the other side or alternatively in the cladding tubes, as can be seen from FIGS. 3a and 3b.

As can be seen in the illustration according to FIGS. 2 and 3, the first plasma unit 27 is shown smaller than the second plasma units 28. This is intended to indicate that the first plasma unit 27 can have a lower power, in particular a lower ignition power than Alternatively, however, it is also possible to form the first plasma unit 27 in the same manner as the second plasma units 28. A separate embodiment in the manner described above is advantageous when the first plasma unit 27 is designated as the ignition unit is used, as will be explained in more detail below.

In FIGS. 1 and 2, a respective plasma region of the respective plasma units 27 and 28 is indicated in the form of a dashed line surrounding the respective plasma unit. This is intended to indicate a customary expansion range of a plasma which is generated by a corresponding plasma unit 27, 28. An actual one 12 HQD-28423

Radiation range of the plasma units before ignition of a plasma can go further than the plasma region shown, as the skilled person can recognize. The plasma units 27 and 28 can be controlled individually and / or in groups. In particular, they can be controlled individually and / or in groups with regard to the power fed in and the time control. This applies in particular to the first plasma unit 27. For this purpose, a control unit, not shown, which is connected in a corresponding manner to the plasma units is provided.

FIG. 4 shows an alternative arrangement of the plasma units 27 and 28, wherein the second plasma units 28 are arranged in the same manner as shown in FIG. However, the second plasma unit 27 extends below and transverse to the first plasma units 28. In this case, the first plasma unit is arranged such that a plasma generated by it lies in a radiation area of all the second plasma units 28 when they are supplied with power. In this case, it is the same for both embodiments according to FIGS. 3 and 4 that the first plasma unit 27 lies outside a projection region of a substrate to be treated, which is indicated by the dashed line in FIGS. 3 and 4.

FIG. 5 shows further arrangement examples of the first plasma unit 27 relative to second plasma units 28, which in turn may be arranged exactly as shown in FIGS. 3 and 4. The first plasma units 27 are shown hatched in FIG. 5 to improve the illustration. The dotted circle in FIG. 5 again represents a projection surface of a substrate to be treated. In FIG. 27 a, an arrangement of the first plasma unit is shown, which substantially corresponds to the arrangement according to FIG. 3, that is to say. the first plasma unit extends substantially parallel to the second one 11 004311

13 HQD-28423

Plasma units 28 and is adjacent to an outer second plasma unit 28th

At 27b the arrangement according to FIG. 4 is shown, in which the first plasma unit extends perpendicular to the second plasma units 28 and a plasma area of the first plasma unit covers the plasma area of all second plasma units.

At 27c, the arrangement of a first plasma unit is shown, which in turn extends substantially parallel to the second plasma units 28, but is formed shorter and moreover between two adjacent plasma units 28 is arranged. The first plasma units may in particular also be arranged above the first plasma units as long as their plasma region overlaps a radiation region of the adjacent second plasma units 28.

At 27d, in turn, a first plasma unit is shown, which extends perpendicular to the sheet plane between two adjacent second plasma units 28.

The first and second plasma units 27, 28 may be of a different basic type and, in particular, they may have different firing powers. In particular, the first plasma unit 27 may have a significantly lower ignition power than the ignition power of the second plasma units 28. Considered to be significantly smaller here is an ignition performance of at most 70% of the ignition power of the second plasma units, preferably a maximum of 50% of the ignition power of the second plasma units. The ignition power of the first plasma unit 27 should preferably have a maximum of 20% or even less than or equal to 10% of the ignition power of the second plasma units 28.

In the different representations, the first plasma units are each shown as not having a projection area of the substrate 2 14 HQD-28423 overlap. Although this may be advantageous to minimize ignition effects on a substrate surface, it is also possible to allow such overlap. It may be advantageous to provide the first plasma unit further apart from the substrate than the second plasma units. However, this is not absolutely necessary, depending on the actual ignition power of the first plasma unit 27, in particular if the ignition power of the first plasma unit lies in a power range in which the second plasma units generate a plasma for a treatment of the substrate 2.

In the embodiments described above, in each case a first plasma unit 27 has been described which differs in terms of its arrangement, size and otherwise from second plasma units. However, it is also possible to dispense with such a separate first plasma unit 27 completely, and to provide only the arrangement of second plasma units 28, provided that they are individually and or in groups controllable.

The operation of the device 1 will be explained in more detail below with reference to the figures.

First, a substrate to be treated is loaded into the process chamber 4 and held in a position and as shown in FIGS. 1 and 2. The process chamber 4 is closed via the door element 13, and a desired gas atmosphere within the process chamber 4 is set. Via the heating arrangement 8, the substrate 2 can be heated to a desired process temperature within the process chamber 4. By preheating the substrate (~ 400 ° C) even the plasma ignition power can be reduced. Directly above the substrate, the gas is as hot as the substrate in a cold wall reactor, and thus a plasma would also be ignitable at a lower power for that reason. Preferably, the substrate may be at a temperature in the range between 15 HQD-28423

100 and 600 ° C, preferably to a temperature of 400 ° C ± 50 ° C preheated.

When the plasma treatment is to start, and a corresponding gas atmosphere is present in the process chamber 4, the first plasma unit 27 is first subjected to an ignition power in order to ignite a plasma in the plasma region of the first plasma unit 27. When the plasma is ignited or even before, at least the adjacent to the first plasma unit 27 plasma unit 28 is applied to a power that is substantially lower than its ignition performance, but sufficient plasma within the plasma region of the second plasma unit 28 upright receive. In particular, the second plasma unit 28 can be supplied with a power with which the plasma is to be subjected to an initial treatment. During the treatment of the substrate 2, the power can then be changed accordingly, but at the beginning, the desired power can be set directly.

Because the first plasma unit 27 has already ignited and the plasma region of the first plasma unit overlaps a radiation region of the directly adjacent second plasma unit 28, a corresponding plasma is also produced adjacent to this second plasma unit 28. This plasma can then be spread in a corresponding manner over the entire second plasma units 28, for example from right to left according to FIG. 2. In this case, the second plasma units 28 can each be exposed to a power which is substantially lower than their ignition power. In particular, they can be directly applied with the power suitable for an initial substrate treatment. The application of an ignition power to the second plasma units 28, which would initially generate very high-energy plasma particles, is not necessary at any time since the respective plasmas in the region of the second plasma units 28 are ignited by adjacent plasmas. 16 HQD-28423

As a result, high-quality coatings can be generated from the outset using plasmas without damaging the substrate surface during the ignition process. In particular, a progressive plasma surface can be generated, which can optionally contribute to a cleaning of the substrate surface.

In the case of an arrangement of the plasma units according to FIG. 4, it would be possible to ignite all other plasma units essentially simultaneously after the ignition of the first plasma unit 27, since in the case of the transversely extending arrangement of the plasma unit 27 to the plasma units 28, the plasma region thereof will be the emission regions of all second plasma units 28 would cover. As one skilled in the art will recognize, the plasma treatment may be controlled from the beginning with a desired plasma power. After the gentle ignition, the plasma power can be increased or decreased (changed) with arbitrary mathematical functions. Of course, the plasma units can also be arranged differently, and it is also possible to provide a distance adjustment between the plasma units and the substrate, as shown, for example, in the unpublished DE 10 2009 060 230. By using a designated firing antenna, such as the first plasma unit 27, it is possible to generate significantly less high-energy plasma particles during the firing process, since the designated firing antenna can be provided with a lower firing power than the main units, ie. the second plasma units 28. By means of a corresponding spatial arrangement outside a projection region of the substrate to be treated, the proportion of the still high-energy plasma particles which hit the substrate can be substantially minimized. By appropriate control of the second plasma units 17 HQD-28423, the initial growth rate of a layer to be formed on the substrate can be greatly reduced, resulting in higher-quality layers with respect to the charge-to-break-down Q _{b (} or the interface state density D _it results.

As an alternative to using a designated ignition antenna, such as the first plasma unit 27, it is also possible to use only one or one of the second plasma units for ignition. This can be realized by implementing a single or group control of the second plasma units. For example, if the first plasma unit 27 were not provided in FIG. 2, for example, the two outer plasma units 28 located outside the projection area of the substrate 2 could be subjected to ignition power at the beginning of the process in order to ignite a plasma in their area. The remaining second plasma units could in turn then be subjected to a much lower power than the ignition power, in turn, to provide a progressive plasma surface. This would run in this example from the outside in. Of course, it would equally be possible to apply ignition power to only one of the outer second plasma units 28 in order to then achieve a plasma fringe advancing from one side to the other. Of course, depending on the arrangement of the plasma electrodes and corresponding control, it is also possible to generate a plasma front from the center to the outside. Preferably, however, the plasma electrode used for the initial ignition of a plasma should each be outside a projection range of the substrate to be treated. As described above, a plasma with small plasma powers can be ignited in the main field of the second plasma units. In this case, a particularly rapid ignition of the respective plasma in the region of the second plasma units 28 is possible, since these are ignited rapidly in each case by an adjacent plasma. Therefore, the present structure is particularly suitable for the application of a pulsed 11 004311

18 HQD-28423

Plasmas during substrate treatment, which can significantly reduce the average power over other pulsed plasmas.

A faster pulse allows faster refreshment of the reactive species. If possible, one, in particular the designated ignition antenna, i. the first plasma unit 27, are operated substantially continuously. Alternatively, it is of course also possible to operate one or more of the second plasma units 28 continuously while the other second plasma units 28 are pulsed. Of course, mutual pulsing of the piasm units would also be possible, as long as there is still a plasma present, to achieve a renewed ignition of the plasma each with a power that is significantly lower than the ignition power of the corresponding plasma unit. For operating the device 1 and in particular for carrying out the cleaning method, it is essential that the plasma units 28 can be ignited sequentially one after the other. The plasma unit 27 ("ignition plasma unit") which overlaps with the plasma area of the adjacent plasma unit 28 and is designed to reduce the required ignition power in the adjacent plasma unit 28 is for performing the method of cleaning the plasma processing apparatus or a substrate accommodated therein 2. In other words, only the customary plasma devices 28 can be provided in the process chamber 4, these plasma units 28 then having to be able to be sequentially ignited one after the other.

In order to build up a plasma wave passing through the process chamber 4 of the plasma processing apparatus 1 or over the substrate 2, it is required that the plasma units 28 be sequentially ignited sequentially. Accordingly, the progressive plasma wave builds up synchronously with the ignition sequence applied to the plasma units 28. 19 HQD-28423

In this case, the plasma units 28 can be ignited in different sequences. For example, it may be provided that the central plasma unit, which is located above the support shaft 20, is ignited first and then the respectively adjacent plasma units 28 such that two plasma waves travel from the center of the process chamber to the edge of the process chamber. The two plasma waves run essentially symmetrically through the process chamber 4. In a further arrangement, it is conceivable to ignite the plasma units 28 from the right side in FIG. 2, ie the side on which the ignition plasma unit 27 is located, and then sequentially Ignite plasma units 28 to the left. In this way, a plasma wave advancing from the left to the right side of the process chamber 4 in FIG. 2 is generated. This makes it possible to dissolve and move particles, which either adhere to components within the process chamber 4 or a substrate 2, due to the progressive plasma wave and to move, as already described above.

Preferably, several plasma waves run in succession through the process chamber 4, for example in the order of 2 to 100 pulses of the plasma, it being possible to work either with the same power or with different powers of the plasma units, ie different or identical plasma intensities can be used for cleaning.

In order to prevent adherence of particles on the substrate 2, this is advantageously heated to a temperature which is higher than the temperature of the ambient gas, preferably to a temperature greater than 50 ° C.

In order to further support the cleaning process, a pressure change is advantageously applied in the process chamber 4, while the plasma wave moves through the process chamber 4. In this case, for example, a fast pump / rinse cycle can be used, in which the purge gas, in particular an inert purge gas or the process gas is admitted from 100 mTorr to 1 Torr and then pumped out again. EP2011 / 004311

 20 HQD-28423

In order to be able to achieve the greatest possible cleaning effect, the generation of the plasma wave is coordinated and takes place simultaneously with the application of the pressure change within the process chamber 4. The cleaning effect can be further enhanced by using appropriate gases in which the pressure wave progresses more slowly, e.g. Gases with larger atomic / molecular mass, as it is easier to coordinate plasma wave and pressure change. Preferably, gas is admitted at the position from which the plasma wave emanates, and the gas is sucked off at the position at which the plasma wave ends. In this way, a fluid flow can be generated which moves in the same direction as the plasma wave. Accordingly, particles dissolved by the plasma wave can be transported away by the gas stream, in particular by being sucked away by means of a suction device. In order to be able to apply such a plasma wave, it is essential that the control device can ignite the respective plasma units sequentially. Accordingly, the respective plasma units 27, 28 are individually controllable. FIG. 6 shows schematically the plasma treatment device 1, which is connected to a control device 40. The control device 40 is designed such that the individual plasma devices 28 can be controlled individually in such a way that plasma devices 28 can be controlled sequentially via the control device 40. In this way, a plasma wave can be generated in the process chamber 4, which moves defined in a direction within the process chamber 4.

The control device 40 is furthermore connected to gas inlet means 41 and gas suction means 42, wherein the control device 40 can control a pressure change in the process chamber 4 in this way and in particular also control a gas flow, in particular of the process gas, from the gas inlet 41 to the gas outlet or to the suction device 42 can, to allow efficient particle transport. 21 HQD-28423

The invention has been explained in detail above with reference to preferred embodiments, without being limited to the specific embodiments shown.

Claims

claims 1. A method for cleaning a plasma treatment device (1) and / or a substrate (2) accommodated in a plasma treatment device (1), wherein the plasma treatment device (1) comprises at least two plasma units (28), characterized in that at least two plasma units ( 28) are sequentially ignited to generate a plasma wave progressing through the plasma processing apparatus (1). 2. The method according to claim 1, wherein at least three plasma units (28) are provided, which are sequentially ignited to generate the progressive plasma wave, so that a directional plasma wave is formed. 3. The method according to claim 2, wherein the sequential ignition of the plasma units generates a plasma wave propagating from one side of the plasma treatment device to its other side, in particular over the substrate and / or through the process chamber. 4. The method of claim 1, wherein the plasma processing apparatus comprises at least three plasma units, wherein the plasma units are sequentially ignited such that at least two plasma waves in the plasma processing apparatus simultaneously run in opposite directions. 5. The method of claim 3, wherein the two plasma waves are symmetrical to each other through the plasma processing apparatus. 6. The method according to any one of the preceding claims, wherein by repeated sequential ignition of the plasma units more plasma waves are generated sequentially, in particular 2 to 10,000 plasma waves. 7. The method according to claim 6, wherein the plasma waves are generated successively at respectively different powers, so that plasma waves of different intensity are generated. 8. The method according to claim 1, wherein a pressure change is generated in the plasma treatment apparatus simultaneously with the generation of the plasma wave, in particular by pumping or purging a gas in the plasma treatment apparatus, in particular in a range from 100 mTorr to 1 Torr. 9. The method according to claim 8, characterized in that a purge gas, in particular an inert gas or a process gas, at the starting location of Plasma wave is initiated. 10. The method according to claim 8 or 9, wherein the purge gas is sucked in the direction of movement of the plasma wave, in particular in an edge region of the plasma treatment apparatus. 1 1. Method according to one of the preceding claims, wherein the substrate is heated simultaneously with the generation of the plasma wave, in particular to a temperature> 100 ° C. A method according to any one of the preceding claims, wherein an ignition power is input to at least a first plasma unit (27) to generate a plasma adjacent thereto in a first plasma region, and then a power is input to at least a second plasma unit (28). the at least in the second The power supplied to the plasma unit is less than the ignition power of the second plasma unit, and wherein the radiation range of the first plasma unit are arranged overlapping with the emission area of the second plasma unit. 13, control device (40) for performing the method according to any one of the preceding claims 1 to 12, characterized in that the control device with the plasma units (28) of a plasma treatment apparatus (1) is coupled such that at least two plasma units of the plasma treatment apparatus can be ignited sequentially to produce a progressive plasma wave. 14. A method for cleaning a plasma treatment apparatus (1) and / or a substrate (2) accommodated in a plasma treatment apparatus (1), wherein the plasma treatment apparatus (1) comprises at least one plasma unit (28), characterized in that it is repeatedly pulsed ignited Generating a pulsatile plasma pressure wave propagating through the device to remove or tear particles from the substrate and / or chamber interior surfaces.