WO2019233703A1

WO2019233703A1 - Plasma treatment device having a linear microwave plasma source and having a gas-conducting device

Info

Publication number: WO2019233703A1
Application number: PCT/EP2019/062043
Authority: WO
Inventors: Joachim Mai
Original assignee: Meyer Burger (Germany) Gmbh
Priority date: 2018-06-06
Filing date: 2019-05-10
Publication date: 2019-12-12
Also published as: DE102018113443A1

Abstract

The invention relates to a plasma treatment device for the plasma treatment of a substrate surface of a substrate, comprising a linear microwave plasma source. The plasma source contains: - a microwave antenna surrounded by a dielectric tube; - a wall having an opening; and - at least two gas inlets. The chamber of the plasma source is divided into a plasma generation region and a plasma treatment zone, the plasma generation region and the plasma treatment zone being connected to each other by a connection zone. The plasma source also has a gas-conducting device, which comprises two parts. The two parts of the gas-conducting device extend from opposite sides of the wall of the plasma source, with mirror symmetry in relation to a plane extending along the axis of the microwave antenna and perpendicularly to a plane of the opening, into the chamber of the plasma source and at least over a portion of the extent of the plasma source in the direction along the axis of the microwave antenna and reduce the width of the connection zone in said portion of the extent of the plasma source in comparison with a plasma source without a gas-conducting device.

Description

Plasma treatment apparatus with a linear microwave plasma source and a gas guiding device

The invention relates to a plasma treatment device with a linear microwave plasma source and a gas guiding device.

Linear microwave plasma sources consist of a rod-shaped microwave antenna, which is arranged in a dielectric tube and is therefore also referred to as an inner conductor of a coaxial conductor arrangement. The outer conductor is then formed by the generated plasma on the dielectric tube. This coaxial conductor arrangement is surrounded by a wall and thereby forms the actual plasma source. The wall of the plasma source in this case has on one side an opening through which the plasma exits from the plasma source and in the vicinity of which a substrate to be treated is arranged outside the plasma source. The plasma source extends along the axis of the rod-shaped microwave antenna with a defined length, wherein the opening has a much smaller width compared to the length of the plasma source, so that it is referred to as a linear plasma source. Such plasma sources are described, for example, in DE 198 12 558 B4.

Plasma treatments, which are carried out with the aid of the plasma generated, are above all layer-separating processes such as CVD (chemical vapor deposition) or layer-removing processes, such as plasma etching. In both cases, often a first gas containing a chemically active ingredient of the process carried out is introduced near a substrate surface of the substrate to be treated into the plasma source, while a second gas containing no or only a negligible chemically active ingredient of the performed process, is introduced into the plasma source near the microwave antenna. With this and with the aid of a spatially defined magnetic field, which is generated by a magnetic device arranged on the plasma source, the space within the plasma source is subdivided into two regions: a plasma generation region in which a plasma is generated from the second gas and which is near and Extends substantially radially symmetrically to the microwave antenna, and in a plasma treatment zone in which the plasma generated in the plasma generation region excites the first gas so far that the desired treatment of the substrate surface takes place. The plasma treatment zone is located substantially near the substrate surface and may extend beyond the actual space of the plasma source. Both areas can also partially overlap, but a substantial spatial separation is advantageous. The overlap area, or an area, that defines the plasma generation area and the Connecting plasma treatment zone with each other, is referred to as the connection zone. Such a plasma treatment device is described, for example, in EP 3 309 815 A1. The first gas and / or the second gas may also be gas mixtures of different gases.

In the known from the prior art plasma treatment devices, however, a significant diffusion of constituents of the first gas from the plasma treatment zone in the direction of the plasma source, which adversely affects the service life of the plasma source and / or the quality of the treated substrate surface or a change in the Process conditions of the performed process leads. In addition, the space within the plasma source is almost completely filled with plasma. Thus, for example, in layer-depositing processes, a layer may grow on the dielectric tube and / or the wall of the plasma source, which on the one hand alters the coupling of the microwave power into the second gas and thus the generation of the plasma and the process conditions of the performed method, and on the other Particle formation and thus a deterioration of the quality of the deposited on the substrate surface layer leads. In addition, the layer deposition on the dielectric tube and / or the wall is often asymmetric, because due to the diffusion direction more components of the second gas reach the substrate facing side of the dielectric tube and the wall of the plasma source than the side facing away from the substrate of the dielectric tube and the wall. This leads to an asymmetric change of the plasma generation conditions in the plasma source, which is particularly difficult to compensate for. As a result, the service life of the plasma source is severely limited, i. the plasma source needs to be cleaned frequently. This leads to loss of productivity and, since the plasma source for cleaning often has to be removed from the plasma treatment apparatus, to an increased effort in disassembly and assembly of the plasma source, for example. With respect to the vacuum tightness of feedthroughs, etc. Similar effects can also coating removal components of the second gas.

It is therefore an object of the present invention to provide a plasma processing apparatus with which the disadvantages of the prior art can be avoided or reduced.

The object is achieved by a plasma treatment apparatus according to claim 1. Preferred embodiments can be found in the subclaims. The plasma treatment device according to the invention for the plasma treatment of a substrate surface of a substrate has a linear microwave plasma source. The plasma source includes a microwave antenna surrounded by a dielectric tube, a wall having an opening and at least two gas inlets, wherein the opening is arranged on the side of the plasma source facing the substrate surface. The wall represents the outer envelope of the plasma source or the space of the plasma source, wherein the at least two gas inlets penetrate the wall and are suitable for introducing gas into the interior of the plasma source, ie the space of the plasma source. Of the at least two gas inlets, a first gas inlet is arranged in the vicinity of the opening, while a second gas inlet of the at least two gas inlets is arranged on a side of the plasma source opposite the opening. Of course, a plurality of first and / or a plurality of second gas inlets may be present, wherein the arrangement of the gas inlets is in each case as described above. The space of the plasma source is divided into a plasma generation area and a plasma treatment area, wherein the plasma generation area and the plasma treatment area are interconnected by a connection zone. During the operation of the plasma processing apparatus, a first gas is introduced into the plasma processing zone by means of the first gas inlet, the first gas containing components which are in an excited state suitable for layer deposition or stratification on the substrate surface while using second gas inlet, a second gas is introduced into the plasma generation region, which is mainly suitable for generating a plasma by means of a voltage applied to the microwave antenna voltage having a frequency in the microwave range, but contains no or only negligible components in an excited state to a layer deposition or a layer removal on or from the dielectric tube or the wall of the plasma source are suitable.

Moreover, the plasma source according to the invention comprises a gas guiding device comprising two parts, the two parts of the gas guiding device being mirror-symmetrical from opposite sides of the wall of the plasma source with respect to a plane which is along the axis of the microwave antenna and perpendicular to a plane of the opening of the wall extends into the space of the plasma source and extend at least over a portion of the extent of the plasma source in the direction along the axis of the microwave antenna. The gas-conducting device is an additional element of the plasma source, which, although connected to the wall of the plasma source and attached to it, is not realized by the wall itself. The two parts of the gas guiding device reduce the width of the connection zone in this part of the extent of the plasma source with respect to a Plasma source without gas guide. As a result, essentially two effects can be achieved. First, the plasma propagation itself and thus the transport of charge carriers in the direction of the plasma treatment zone can be influenced. Secondly, the gas conduction device can also be used to adapt the transport of gas particles between the plasma generation region and the plasma treatment zone. By the Gasleitvorrichtung the Strömungsleitwert for the second gas and the plasma generated therefrom from the plasma generation region is changed in the plasma treatment zone such that on the one hand, the second gas and the plasma generated therefrom substantially completely surrounds the dielectric tube and the diffusion of the first gas from the Plasma excitation zone is reduced or almost suppressed in the plasma generation region with respect to a plasma source without gas guide. Thus, a layer deposition or a layer-removing attack of the first gas on the dielectric tube and the wall of the plasma source in the region of the plasma generation region is greatly reduced or completely prevented. Secondly, the plasma treatment zone is reduced in width as measured transverse to the axis of the microwave antenna, whereby a smaller amount of the excited first gas reaches the plasma source wall in the plasma treatment zone and the wall in that region is less liable to become coated or stratified Attack is subject. As a result of both effects, the service life of the plasma source is increased and the controllability of the plasma treatment and the quality of the layer deposition or layer removal improved.

The gas-conducting device may consist of an electrically conductive or electrically insulating material or of a plurality of different materials, which may be present above or next to one another. Preferred materials are stainless steel, aluminum and titanium sheet. However, it is also possible to use ceramics such as aluminum oxide, zirconium oxide, etc. or various glasses or glass ceramics or even quartz glass. In some applications, carrier materials are used which are coated with different functional layers. Preferably, the gas guiding device is made of the same material and with the same thickness as the wall of the plasma source.

The plasma source may have different shapes in a cross section through the plasma source transverse to the axis of the microwave antenna. For example, the plasma source may be trapezoidal, with an upper side of the wall opposite the opening of the plasma source parallel to the plane of the opening and the plasma source wall having flat side surfaces between the upper side and the opening. Other embodiments of the plasma source are bell-shaped with a partially circular wall formed, wherein the rounding of the wall on the opening of the plasma source opposite side of the wall is arranged and a semicircular arc or another portion of a circular arc maps or oval, elliptical or otherwise round, ie not angular, runs.

The plasma processing apparatus may be a continuous type apparatus in which a substrate is continuously and linearly and unidirectionally, i. along a line from an entrance to an exit, through a plasma treatment chamber and past the opening of the plasma source, or a closed device, in which a substrate is introduced into a plasma treatment chamber, treated stationary or quasi-stationary therein and then discharged again. By quasi-stationary is meant a movement of the substrate with respect to the plasma source, but the substrate is not moved continuously and linearly and unidirectionally from an input to an output of the plasma processing chamber. This quasi-stationary movement can be rotating, linear, oscillating or different or a combination of different movements.

In a first embodiment, the two parts of the gas guiding device each have a first region which extends in a plane parallel to the plane of the opening of the wall, wherein a first end of the first region adjoins the wall of the plasma source.

In a first embodiment of the first embodiment, the two parts of the Gasleitvorrichtung each have a second region extending from a second end of the first region of straight at an angle greater than or equal to 90 ° and less than 180 ° in the direction of the plane of the opening of the wall extends, wherein the second end of the first region opposite to the first end of the first region.

In a second embodiment of the first embodiment, the two parts of the gas guiding device each have a second region which extends from a second end of the first region of a circular arc in the direction of the plane of the opening of the wall, wherein the second end of the first region of the first end of the first region and wherein the radius of the circular arc of the second region is greater than the radius of the dielectric tube.

In a particular embodiment of the second embodiment of the first embodiment, the wall of the plasma source in a region extending from a plane which is parallel to the plane of the opening of the wall through the axis of the microwave antenna, in the direction of the Opening opposite side of the plasma source formed as a hollow half-cylinder, wherein the radius of the half-cylinder is greater than the radius of the arc of the second region of the gas guide.

In a particular embodiment of the first or second embodiment of the first embodiment, the two parts of the Gasleitvorrichtung each have a third region extending from the second end of the first region of straight at an angle greater than or equal to 90 ° and less than 180 ° in the direction of the opening opposite side of the plasma source extends.

In a particular embodiment of the first or second embodiment of the first embodiment, the two parts of the Gasleitvorrichtung each have a third region which extends from the second end of the first region of a circular arc in the direction of the opening opposite side of the plasma source, wherein the radius of the arc of the second region is greater than the radius of the dielectric tube. If the second embodiment of the first embodiment is present, i. If the second regions are also circular-arc-shaped, the radius of the circular arc of the third region is preferably equal to the radius of the circular arc of the second region.

In the presence of third regions of the gas-conducting device, the distance between two first ends of the third regions is preferably greater than 0, but smaller than the distance between two first ends of the second regions of the two parts of the gas-conducting device. In this case, the first ends of the second regions and the first ends of the third regions, in each case the ends, which are opposite to a second end of the respective region which adjoins the first region.

In the first embodiment, the plane in which the first regions extend preferably passes through the axis of the microwave antenna.

In another preferred embodiment of the first embodiment, the plane in which the first regions extend is arranged between the axis of the microwave antenna and the plane of the opening of the wall.

In a second embodiment of the plasma treatment device according to the invention, the two parts of the gas guiding device each have a first region, which differs from the Wall of straight line extends at an angle greater than 0 and less than 90 ° with respect to the plane of the opening of the wall in the direction of the plane of the opening of the wall.

In a third embodiment of the plasma processing apparatus according to the invention, the wall of the plasma source in a region extending from a plane parallel to the plane of the opening of the wall through the axis of the microwave antenna in the direction of the opposite side of the plasma source, as hollow Half cylinder formed and the two parts of the gas guide device each have a first region which extends in a circular arc from the wall of the plasma source in the direction of the substrate surface. The radius of the half-cylinder is equal to the radii of the circular arcs of the first regions of the gas guiding device and the centers of the half-cylinder and the arcs of the first regions coincide with the axis of the microwave antenna. Also in the second and third embodiments, the two parts of the gas guide device may again have second portions extending from a second end of the first portion similar to that described with respect to the first embodiment. The second end of the first region is again opposite a first end of the first region which adjoins the wall.

Preferably, in all embodiments, the connection points of the gas directing device to the wall of the plasma source, i. the first ends of the first regions farther from the plane of the opening of the wall than the first gas inlet.

In all embodiments, the gas-conducting device is preferably arranged movably on the wall of the plasma source. Thus, the gas guiding device can advantageously be changed in its orientation with respect to the plane of the opening of the wall or be folded away to remove the wall of the plasma source.

Preferably, the plasma source comprises a plurality of gas guiding devices, each of the gas guiding devices being arranged in a partial area of the extent of the plasma source in the direction along the axis of the microwave antenna, which is different from other partial areas in which another of the gas guiding devices is arranged. In other words, along the extent of the plasma source along the axis of the microwave antenna, different gas guiding devices can be arranged, each of which is adapted in its design to the peculiarities of the respective subarea. The invention will be explained in more detail with reference to the figures. The sizes of the individual components as well as the distances between them are not shown to scale.

Show it:

1 shows a plasma treatment device according to the invention with a first embodiment of a first embodiment of the gas guiding device and a first form of the plasma source,

2 shows a plasma treatment device according to the invention with the first embodiment of the first embodiment of the gas guiding device and a second form of the plasma source,

3 shows a plasma treatment device according to the invention with a second embodiment of the first embodiment of the gas guiding device and the first form of the plasma source,

4 shows a plasma treatment device according to the invention with a third embodiment of the first embodiment of the gas guiding device and the first form of the plasma source,

5 shows a plasma treatment device according to the invention with the third embodiment of the first embodiment of the gas guiding device and the second form of the

Plasma source,

6 shows a plasma treatment device according to the invention with a fourth embodiment of the first embodiment of the gas guiding device and the first form of the

Plasma source,

7 shows a plasma treatment device according to the invention with a fifth embodiment of the first embodiment of the gas guiding device and the first form of the

Plasma source,

8 shows a plasma treatment device according to the invention with a sixth embodiment of the first embodiment of the gas guiding device and the first form of the plasma source,

9 shows a plasma treatment device according to the invention with a seventh embodiment of the first embodiment of the gas guiding device and the first form of the

Plasma source,

10 shows a plasma treatment device according to the invention with a second

Embodiment of the gas guiding device and the first form of the plasma source and

11 shows a plasma treatment device according to the invention with your third one

Embodiment of the gas guiding device and the second form of the plasma source. In each case, cross sections are shown transversely to the axis of a microwave antenna.

FIG. 1 shows a plasma treatment apparatus 1 according to the invention which contains a plasma treatment chamber 10 with a wall 11. In the plasma processing chamber 10, one or more substrates 21 are to be treated on their substrate surface 22 by means of a plasma assisted process. In the illustrated case, the plasma treatment apparatus 1 is a continuous device in which the substrate or substrates 21 are moved through the plasma treatment chamber 10 linearly from a first opening 12 in the wall 1 1 to a second opening 13 in the wall 1 1, wherein the second opening 13th the first opening 12 is opposite. For this purpose, the substrates 21 are usually arranged on a substrate carrier 2, which moves in the example shown along the x-axis. The plasma treatment device 1 further comprises one or more gas exhaust ports 14, at which, for example, one or more vacuum pumps and pressure regulating devices are provided, with which within the plasma treatment chamber 10 an atmosphere defined at least in terms of pressure can be generated. Furthermore, the plasma treatment apparatus 1 has a microwave plasma source 3, hereinafter referred to as plasma source 3. The plasma source 3 has a wall 30 with an opening 31, which is opposite to the substrate surface 22. The distance HO between the plane of the substrate surface 22 and the plane of the opening 31 is, for example, 5 mm to 50 mm. The width SO of the opening 31 is, for example, 120 mm to 180 mm.

Within the wall 30, a linear microwave antenna 32 is arranged, which has a circular shape in the illustrated cross-section and extends rod-shaped along the y-axis. The microwave antenna 32 is surrounded by a dielectric tube 33, which has an annular cross-section and also extends along the y-axis. The distance H between the axis of the microwave antenna 32 and the opening 31 of the wall 30 is typically in the range of 60 mm to 100 mm. On the outer sides of the wall 30 magnetic devices 34 are arranged, which generate a magnetic field within the plasma source 3 and can be moved along the wall 30.

Near the opening 31, ie between the microwave antenna 32 and the dielectric tube 33 on the one hand and the opening 31 on the other hand, first gas inlets 35a and 35b are arranged, through which, with the aid of gas lines, a first gas which has, at least in the excited state, layer-forming or layer-removing constituents is admitted into the plasma source 3 and in adjacent areas of the plasma processing chamber 10. Depending on the technology requirements, however, only a first gas inlet can be unilaterally at the opening 31 to be ordered. Often, a gas pumping device is then arranged in the wall 30 of the plasma source 3 or in the wall 11 of the plasma chamber 10 on the side of the opening 31 opposite the first gas inlet. This results in a change in the consumption conditions of the gas or gas mixture introduced at the first gas inlet from the first gas inlet to the opposite side at the opening 31 as a result of the outflow of the first gas, whereby the layer deposition or layer removal across the width of the opening 31 can result. Of course, more than two first gas inlets can be arranged in the plasma source 3 as described.

On an upper side of the wall 30, which is opposite to the opening 31, a second gas inlet 36 is arranged, through which a second gas is introduced into the plasma source 3. Thus, in contrast to the first gas, the second gas is introduced far from the substrate surface 22 to be processed, the microwave antenna 32 and the dielectric tube 33 being arranged between the second gas inlet 22 and the opening 31. Of course, a plurality of second gas inlets 36 may be arranged within the plasma source 3. From the second gas, a plasma is generated in a plasma generation region 37 in the operating state of the microwave antenna 32, which excites the first gas in a plasma treatment zone 38 to such an extent that the desired treatment of the substrate surface 22 takes place. The plasma generation region 37 and the plasma treatment zone 38 are interconnected by a connection zone 39 in which plasma particles are present, but where plasma is hardly regenerated and in which there is a reduced amount of the first gas compared to the plasma treatment zone 38.

According to the invention, the plasma source 3 further includes a gas guiding device 40 comprising two parts 40a and 40b, each opposite to opposite sides of the wall with respect to a plane passing through the axis of the microwave antenna 32 and perpendicular to a plane of the opening 31 of the wall 30 30 are fixed and from there into the interior of the plasma source 3 and at least over part of the plasma source 3 in the direction along the axis of the microwave antenna 32, ie in the y-direction, extend. In the illustrated embodiment of the first embodiment, the parts 40a and 40b of the gas guiding device are each formed by a first region 41 which extends in a plane parallel to the plane of the opening 31, which in the illustrated case extends parallel to the substrate surface 22. The first region 41 is in each case at a first end 41 1 of the first region 41 with the wall

30 firmly and gastight connected. The width S of the opening of the gas guiding device 40 to the opening

31 is determined in this embodiment by the distance from second ends 412 of the first regions 41 from each other, wherein the second ends 412 respectively the first ends 41 1 of corresponding first portion 41 opposite. In this case, the plane in which the opening of the gas guiding device 40 is arranged to the opening 31 and which coincides in the illustrated embodiment with the plane in which the first regions 41 are arranged, between the axis of the microwave antenna 32 and the plane of the opening The distance H1 and the width S influence the plasma expansion within the plasma source 3 and the gas flow of the second gas from the second gas inlet 36 in the direction of the substrate surface 22. By Gasleitvorrichtung 40 it comes to a Increasing the flow rate of the second gas in the direction of the substrate surface 22, whereby the gas transport of the first gas toward the dielectric tube 33 is reduced.

The concrete dimensioning of the distance H1 and the width S strongly depend on the required technology conditions. Thus, second gases from the second gas inlet 36 at high gas flows produce greater pressure differences and higher gas particle velocities in the region of the gas guide device 40 than at lower gas flows. The gas types of the first and the second gas and the working pressure range within the plasma source 3 and also the gas flow ratios between the first gas, which is inserted near the substrate surface 22, and the second gas, which is inserted near the plasma generating region 37, play a part important role. There are very complex relationships between the process parameters and the resulting particle transport conditions. The dimensions of all mentioned in the present application sizes of the gas-conducting device 40 is therefore obtained mainly from model calculations and simulations using powerful software. In addition, a compromise between the influence of the gas directing device 40 on the transport conditions of the plasma particles and the desired concentration gradient of the first gas from the first gas inlets 35a and 35b in the direction of the plasma generation region 37 usually needs to be compromised. Typical values for the width S are in the range of 30 mm to 50 mm, while typical values for the distance H 1 are in the range of 0 mm to 50 mm. In this case, these values are adapted to the diameter of the dielectric tube 33 or the distance H between the axis of the microwave antenna 32 and the opening 31. Along the extent of the plasma source 3 in the direction of the axis of the microwave antenna 32, ie in the y-direction, the width S and / or the distance H1 can vary. Thus, for example, in some sub-regions along the y-direction, the width S may also be 0 (zero), so that the opening of the gas guiding device 40 to the opening 31 over the entire extent of the plasma source 3 along the axis of the microwave antenna 32 by a plurality of delimited from each other Openings is formed. In the embodiment of FIG. 1, the plasma source 3 has a trapezoidal cross-section in which the upper side of the wall 30 opposite the opening 31 is parallel to the plane of the opening 31 and the lateral parts of the wall 30 are at an obtuse angle from the upper side Direction of the plane of the opening 31 are rectilinear. This form of the plasma source 3 is referred to below as the first form of the plasma source 3.

In the following figures, only the plasma source 3 is shown in each case, wherein the other elements of the plasma treatment device, although not shown, but are formed equal to Figure 1.

Figure 2 shows a second form of the plasma source 3. The second form of the plasma source 3 is defined by a circular shape of the plasma source 3 in the region above the axis of the microwave antenna 32, i. in the positive z-direction or in the opening 31 opposite region of the plasma source. Thus, the wall 30 is formed in this area as a hollow half cylinder with a radius R. Below the axis of the microwave antenna 32, the wall 30 again runs straight and at an acute angle to the plane of the opening 31. The radius R is chosen so that in the operating state of the microwave antenna 32, i. when the microwave power is applied, as far as possible a large proportion of the microwave power is reflected back into the plasma generation area in phase. The radius R depends on the wavelength of the microwave frequency used and the dimensions of the microwave antenna 32 and the dielectric tube 33, i. from the diameter Di of the microwave antenna 32 and the diameter Da of the dielectric tube 33. The gas guiding device 40 is formed similar to that of FIG.

The magnetic devices 34 are also arranged displaceably on the wall 30 and can be freely positioned along the wall 30. As in all embodiments and embodiments of the plasma source 3, the magnetic devices 34 may be made attractive or repellent to each other.

FIG. 3 shows a plasma source 3 with a second embodiment of the first embodiment of the gas-conducting device 40, wherein the plasma source 3 again has the first shape. In the second embodiment, the gas-conducting device 40 has a second area 42 in each of its two parts 40a and 40b, in each case adjacent to the first area 41. This is just trained and extends from the second end 412 of the first region 41 from straight at an angle a in the direction of the plane of the opening 31 of the wall 30. In this case, the angle a between the the opening 31 facing lower side of the first region 41 and the second region 42 measured. The angle a is greater than or equal to 90 ° and smaller than 180 °, with concrete values, as already stated above with respect to the width S and the distance H 1, again depend on many factors and are preferably determined by means of a simulation. The first regions 41 are arranged in a plane which has a distance H2 to the axis of the microwave antenna 32 and runs parallel to the plane of the opening 31. The two second ends 412 of the first regions 41 are spaced apart by a distance S1 that is greater than the width S of the opening of the gas guiding device 40. The width S corresponds to the distance from first ends 421 of the second regions 42, wherein the first ends 421 are opposite to second ends of the second regions 42, which adjoin the first ends 412 of the first regions 41. The opening of the gas guide 40 is again in a plane with the distance H1 from the axis of the microwave antenna 32, as already described with reference to FIG. The second regions 42 thus form, together with the dielectric tube 33, a flow channel, in particular for the first gas. By selecting the distances H1, H2 and S1 and the width S, the plasma propagation in the plasma source 3 and the gas flow resistance can be optimized in a simple manner. As compared with the first embodiment shown in Figs. 1 and 2, through the second region 42 and the adjacent arc portion of the dielectric tube 33, it becomes possible to set a higher gas flow resistance.

FIG. 4 shows a plasma source 3 with a third embodiment of the first embodiment of the gas guiding device 40 and the first form of the plasma source 3. Here, unlike the second embodiment described with reference to FIG. 3, the second region 42 of the gas guiding device 40 respectively circular arc or formed in the form of a portion of a hollow cylinder. The circular arc-shaped second regions 42 thus form segments of the circumference of a hollow cylinder with the radius R1, wherein the radius R1 is greater than the radius of the dielectric tube 33 and, for example, in the range of 16 mm to 20 mm. The specific value for R1 is highly dependent on the gas pressure and microwave power conditions and must be selected accordingly. Moreover, in contrast to FIG. 3, the first regions 41 are arranged in a plane which runs through the axis of the microwave antenna 32. The circular arc-shaped configuration of the second regions 42 is particularly advantageous for a good flow around the dielectric tube 33 by the second gas, whereby the dielectric tube 33 is particularly well protected from a coating or a coating-removing treatment by the first gas. The flow resistance of the gases in the plasma source 3 can be adjusted via the radius R1 and the width S of the opening of the gas-conducting device 40. FIG. 5 shows that the third embodiment of the gas-conducting device 40 explained with reference to FIG. 4 can also be formed in a plasma source 3 with the second shape. The radius R1 is smaller than the radius R of the half cylinder of the wall 30, but relatively independently of the radius R selectable.

The fourth embodiment of the gas guiding device 40 shown in FIG. 6 differs from the third embodiment explained with reference to FIG. 4 in that the plane in which the first regions 41 are arranged is opposite the plane which runs through the axis of the microwave antenna 32 , is displaced in the direction of the opening 31 of the wall 30 and now has a distance H2 to the axis of the microwave antenna 32. The center of the circular arc-shaped second regions 42 continues to lie in the same plane as the first regions 41 and is therefore also displaced from the axis of the microwave antenna 32 by the distance H2.

FIG. 7 shows a plasma source 3 with a fifth embodiment of the first embodiment of the gas guiding device 40 and the first form of the plasma source 3. In addition to the first and second regions 41 and 42, the parts of the gas guiding device 40 now each have third regions 43. The third region 43 extends from the second end 412 of the first region 41 in each case in a direction towards the upper side of the wall 30, which is opposite to the opening 31. In this case, the third area 43 is arranged at an angle β to an upper side of the first area 41, which faces away from the opening 31, and is designed to be planar. The angle β is greater than or equal to 90 ° and less than 180 °, with specific values, as already indicated with respect to other dimensions of the gas-conducting device 40, again depending on many factors and preferably determined by means of a simulation. The first regions 41 are arranged in a plane which runs through the axis of the microwave antenna 32 and parallel to the plane of the opening 31, but may be arranged in other configurations but also in another plane parallel thereto. The two first ends 431 of the third regions 43 are spaced apart by a distance S2 which is smaller than the width S of the opening of the gas guiding device 40, but in other embodiments may be equal to or greater than the width S. In this case, the first ends 431 are opposite to second ends of the third regions 43, which adjoin the first ends 412 of the first regions 41. The first ends 431 lie in a plane at the distance H3 from the axis of the microwave antenna 32, this plane being spaced from the upper side of the wall 30. In other embodiments, however, the third areas can also reach up to the upper side of the wall 30, as long as the second gas still through the second gas passage in a Space between the third regions and the dielectric tube can be embedded. By selecting the distances H1, H3, S1 and S2 and the width S, the plasma propagation in the plasma source 3 and the gas flow resistance can be optimized in a simple manner. Here simulations are used.

FIG. 8 shows a plasma source 3 with a sixth embodiment of the first embodiment of the gas-conducting device 40 and the first form of the plasma source 3. The sixth embodiment differs from the fifth embodiment in that the second and third regions 42 and 43 are each formed as circular-arc-shaped regions like this for the second areas

42 has already been explained in principle with reference to FIG. 4. In this case, the third regions 43 are subregions of the same hollow cylinder as the second regions 42. The center of the arcuate second and third regions 42 and 43 coincides with the axis of the microwave antenna 32. The first areas 41 are arranged in a plane passing through the axis of the microwave antenna 32 and parallel to the plane of the opening 31. The two first ends 431 of the third regions 43 are spaced apart by a distance S2 which is smaller than the width S of the opening of the gas guiding device 40, but in other embodiments may be equal to or greater than the width S. In this embodiment, besides the distance S2 between the first ends 431 of the third regions

43 and the width S of the opening of the gas guide 40 of the radius R1 of the second and third regions 42 and 43, a parameter for the optimization of the plasma expansion in the plasma source 3 and the gas flow resistance. In this case, typical values are in each case in the areas already mentioned with reference to FIG. 4 or FIG. 7. The distance H1 between the axis of the microwave antenna 32 and the plane in which the first ends 421 of the second regions 42 and thus the opening of the gas-conducting device 40 lie results from the desired width S and the radius R1 or vice versa.

FIG. 9 shows a plasma source 3 with a seventh embodiment of the first embodiment of the gas-conducting device 40 and the first form of the plasma source 3. The seventh embodiment differs from the fifth embodiment, illustrated in FIG. 7, in that the two third regions 43 extend through a connection region 44 which extends parallel to the upper side of the wall 30, are interconnected. The connection region 44 thus adjoins the first ends 431 of the third regions 431. In order to be able to feed the second gas into the plasma generation region, the second gas inlet 36, which penetrates the connection region 44 and is connected to a gas line, is arranged within the connection region 44. Thus, the second gas in the plasma generation region becomes within the space occupied by the second regions 42, the third regions 43 and the second region Connecting region 44 and the dielectric tube 33 is formed, particularly well utilized for plasma generation.

Similarly, the sixth embodiment shown in Fig. 8 may be formed, wherein the first ends of the third regions are then also connected to each other by a flat or curved connection region or wherein the distance S2 between the first ends of the third regions is 0 (zero ).

Of course, embodiments of the gas-conducting device can also be formed, in which circular-arc-shaped second regions with flat third regions and optionally a connecting region or even second regions with circular third regions are combined. Also, an embodiment of further regions, which adjoin the first ends of the second or third regions, are circular-arc-shaped or planar and thus enable a further defined design of the flow path of the second gas, are possible.

All previously illustrated embodiments of the first embodiment of the gas guide 40 was a first portion 41 which extends in a plane which is parallel to the plane of the opening 31 of the wall 30 extends. Other embodiments will be explained with reference to the following figures.

FIG. 10 shows a plasma source 3 with a second embodiment of the gas guiding device 40, in which plane rectilinear first regions 41 'extend in a plane towards the plane of the opening 31, the plane of the first regions 4T not being parallel to the plane of FIG Opening 31 of the wall 30, but at an acute angle g to the plane of the opening 31 extends. Concrete values of the angle g again depend on many factors and are preferably determined by means of a simulation. The first regions 41 'are gas-tightly adjacent to the wall 30 with first ends 41 1, while the second end 412 of the first regions 41', which are opposite the first ends 41 1, are located in a plane at a distance H 1 from the axis of the microwave antenna 32 , The second ends 412 thereby form the opening of the gas guiding device 40 to the opening 31, wherein the distance of the second ends 412 from one another represents the width S of the opening of the gas guiding device 40. The first ends 41 1 are located approximately the same, parallel to the opening 31 plane as the axis of the microwave antenna 32 may be arranged in other embodiments but also in another plane. The second embodiment of the gas guiding device 40 can be used both for the first and for the second form of the plasma source 3. FIG. 11 shows a plasma source 3 with a third embodiment of the gas-conducting device 40, in which arc-shaped first regions 41 "extend in the direction of the plane of the opening 31. In the illustrated second form of the plasma source 3, in which the region of the wall 30 lying above the axis of the microwave antenna 32 is formed as a hollow half-cylinder with the radius R, the radius of the first regions 41 "is equal to the radius R. In other words: The first regions 41 "and the upper region of the wall 30 form an almost complete hollow cylinder whose center coincides with the axis of the microwave antenna 32. However, in the lower region opposite to the opening 31, the hollow cylinder has an opening with the width S. On the hollow cylinder, a lower portion 30a of the wall 30 is arranged, which extends from the plane of the axis of the microwave antenna 32 to the opening 31 of the wall 30 as a planar region at an acute angle to the plane of the opening 31 of the wall 30. In the lower portion 30a, the first gas inlets 35a and 35b are arranged. The first regions 41 "are gas-tightly adjacent to the wall 30 with first ends 41 1, while second ends 412 of the first regions 41" facing the first ends 41 1 lie in a plane with a distance H 1 to the axis of the microwave antenna 32 are located. The second ends 412 thereby form the opening of the gas guiding device 40 to the opening 31, wherein the distance of the second ends 412 from one another represents the width S of the opening of the gas guiding device 40.

Also, the gas guiding device 40 in the second or third embodiment may have, in addition to the first regions 4T and 41 ", second regions 42, as explained with reference to FIGS. 3 to 9.

The values given for distances and widths of openings are similar for all configurations (as far as they are occurrences) and can be selected according to the specific requirements of the plasma treatment, for example with the aid of simulations. The opening of the gas-conducting device 40 having the width S is in each case arranged above the plane of the opening 31 of the wall 30 of the plasma source 3, i. between the plane of the opening 31 and the axis of the microwave antenna 32.

In order to allow removal of the wall 30 of the plasma source 3, which is preferably taken upwards, ie in the positive z-direction, without the gas-conducting device 40 touching or damaging the dielectric tube 33 or the microwave antenna 32, the first ones are Areas 41, 4T or 41 "movably attached to the wall 30. Thus, they can be folded away before the removal of the wall 30 towards the wall, preferably downwards, ie in the direction of the substrate surface 22, whereby the width S of the Opening the gas guide 40 is increased. Also optionally present second or third areas 42 and 43 may be movably attached to the respective first area 41, 41 ', 41 "to facilitate removal of the wall 30 or the width S of the opening of the gas guide 40 or the distance S2 between the first ends 431 of the third regions 43 to change. By changing the width S or the distance S2, the flow conditions of the gases in the plasma source 3 can be adjusted and adapted to possible changes in the plasma process.

Preferably, the plasma source 3 is mirror-symmetrical to the plane passing through the axis of the microwave antenna 32 and perpendicular to the plane of the opening 31 of the wall 30, as shown in the figures. However, individual components of the plasma source may also be arranged asymmetrically or may be present only in one of the parts of the plasma source defined by said plane.

Components of said options for the design of the gas-conducting device 40 can also be combined with one another, as long as they do not exclude each other. Moreover, the presented gas guide device 40 can be used in various types of plasma treatment apparatus and for various forms of plasma source 3 and is not limited to the cases illustrated here.

reference numeral

1 plasma treatment device

10 plasma treatment chamber

1 1 Wall of the plasma chamber

12, 13 openings for insertion and removal of a substrate

14 gas pumping opening

2 substrate carrier

21 substrate

22 substrate surface

3 plasma source

30 wall of the plasma source

30a Lower part of the wall

31 opening of the wall

32 microwave antenna

33 Dielectric pipe

34 magnetic device

35a, 35b First gas inlet

36 second gas inlet

37 plasma generation area

38 plasma treatment zone

39 connection zone

40 gas guiding device

40a, 40b parts of the gas guiding device

41, 41 ', 41 "first region of the gas guiding device

411 First end of the first area

412 Second end of the first area

42 Second region of the gas guiding device

421 First end of the second area

422 Second end of the second area

43 Third area of the gas guiding device

431 First end of the third area

432 Second end of the third area

44 connecting region between the third regions of the gas guiding device Because diameter of the dielectric tube

Di diameter of the microwave antenna

H Distance between the opening of the wall and the axis of the microwave antenna

HO distance between substrate surface and opening of the wall

H1 distance between opening of the gas guide device to the substrate surface and axis of the microwave antenna

H2 distance between plane of the first areas and axis of the

microwave antenna

H3 distance between the plane of the first ends of the third regions and the

Axis of the microwave antenna

R radius of the wall

R1 Radius of the arc of the second areas

S width of the opening of the gas guide for opening the wall

50 width of the opening of the wall

51 Distance between second ends of the first areas

52 Distance between first ends of the third areas

Claims

claims

A plasma processing apparatus (1) for plasma treatment of a substrate surface (22) of a substrate (21) with a linear microwave plasma source (3), wherein the

Plasma source (3) includes a microwave antenna (32) surrounded by a dielectric tube (33), a wall (30) having an opening (31) and at least two gas inlets (35a, 35b, 36), the opening (31) being located on the of the at least two gas inlets (35a, 35b, 36), a first gas inlet (35a, 35b) is arranged in the vicinity of the opening (31), while a second gas inlet (36) of the at least two gas inlets is disposed on an opposite side of the plasma source (3) from the opening (31), and the space of the plasma source (3) is subdivided into a plasma generation region (37) and a plasma treatment zone (38) the plasma generation region (37) and the

Plasma treatment zone (38) are interconnected by a connection zone (39), characterized in that the plasma source (3) comprises a gas guide device (40) comprising two parts (40a, 40b), the two parts (40a, 40b) the gas guiding device (40) from opposite sides of the wall (30) of the plasma source (3) in mirror symmetry with respect to a plane which extends along the axis of the microwave antenna (32) and perpendicular to a plane of the opening (31) in the space of Plasma source (3) and at least over a portion of the extension of the plasma source (3) in the direction along the axis of the microwave antenna (32) extend and the width of the connection zone (39) in this part of the extension of the plasma source (3) relative to a plasma source without Reduce the gas guiding device.

2. Plasma treatment apparatus according to claim 1, characterized in that the two parts (40a, 40b) of the gas guiding device (40) each have a first region (41) which extends in a plane parallel to the plane of the opening (31), wherein a first end (411) of the first region (41) adjoins the wall (30) of the plasma source (3).

A plasma processing apparatus according to claim 2, characterized in that the two parts (40a, 40b) of the gas guiding device (40) each have a second region (42) rectilinearly extending from a second end (412) of the first region (41) at an angle (a) greater than or equal to 90 ° and less than 180 ° in the direction of the plane of the opening (31), wherein the second end (412) of the first region (41) corresponds to the first end (41 1) of the first region (41). 41) is opposite.

4. plasma treatment apparatus according to claim 2, characterized in that the two parts (40a, 40b) of the gas guiding device (40) each have a second region (42) extending from a second end (412) of the first region (41) of a circular arc extending in the direction of the plane of the opening (31), wherein the second end (412) of the first region (41) opposite the first end (41 1) of the first region (41) and wherein the radius (R1) of the arc of the second region (42) is greater than the radius of the dielectric tube (33).

A plasma processing apparatus according to claim 4, characterized in that the wall (30) of the plasma source (3) extends in a region extending from a plane parallel to the plane of the aperture (31) through the axis of the microwave antenna (32). extending in the direction of the opening (31) opposite side of the plasma source (3) is formed as a hollow half-cylinder, wherein the radius (R) of the half-cylinder is greater than the radius (R1) of the arc of the second region (42) of the gas guiding device (40 ).

Plasma treatment apparatus according to any one of claims 3 to 5, characterized in that the two parts (40a, 40b) of the gas guiding device (40) each have a third region (43) extending from the second end (412) of the first region (4). 41) extends in a straight line at an angle (β) greater than or equal to 90 ° and smaller than 180 ° in the direction of the opening (31) opposite side of the plasma source (3).

7. A plasma processing apparatus according to any one of claims 3 to 5, characterized in that the two parts (40a, 40b) of the gas guiding device (40) each have a third region (43) extending from the second end (412) of the first region (4). 41) of circular arc in the direction of the opening (31) opposite side of the plasma source (3), wherein the radius of the circular arc of the third region (43) is greater than the radius of the dielectric tube (33).

8. plasma treatment apparatus according to claim 4 and 7, characterized in that the radius of the circular arc of the third region (43) is equal to the radius (R1) of the circular arc of the second region (42).

9. plasma treatment apparatus according to any one of claims 6 to 8, characterized in that the distance (S2) between two first ends (431) of the third regions (43) of the two parts (40a, 40b) of the gas guiding device (40) greater than 0, but smaller than the distance (S) between two first ends (421) of the second regions (42) of the two parts (40a, 40b) of Gas guiding device (40), wherein the first ends (421) of the second regions (42) and the first ends (431) of the third regions (43) are each the ends which correspond to a second end of the respective region (42, 43), which is adjacent to the first area (41), opposite.

A plasma processing apparatus according to any one of claims 2 to 9, characterized in that the plane in which the first regions (41) extend extends through the axis of the microwave antenna (32).

A plasma processing apparatus according to any one of claims 2 to 9, characterized in that the plane in which the first regions (41) extend is disposed between the axis of the microwave antenna (32) and the plane of the aperture (31).

12. Plasma treatment apparatus according to claim 1, characterized in that the two parts (40a, 40b) of the gas guiding device (40) each have a first region (4T) extending from the wall (30) straight at an angle (y) larger 0 and less than 90 ° with respect to a plane of the opening (31) in the direction of the opening (31), wherein a first end (41 1) of the first region (4T) adjacent to the wall (30) of the plasma source (3) ,

A plasma processing apparatus according to claim 1, characterized in that the wall (30) of the plasma source (3) extends in a region extending from a plane parallel to the plane of the aperture (31) through the axis of the microwave antenna (32). extending in the direction of the opening (31) opposite side of the plasma source (3), is formed as a hollow half-cylinder and the two parts (40a, 40b) of the gas guiding device (40) each having a first region (41 "), which differs from the Wall (30) of the plasma source extends in a circular arc in the direction of the plane of the opening (31), wherein the radius (R) of the half cylinder is equal to the radii of the circular arcs of the first regions (41 ") of the gas guiding device (40) and wherein the centers of the Half cylinder and the circular arcs of the first areas (41 ") coincide with the axis of the microwave antenna (32).

14. Plasma treatment apparatus according to one of the preceding claims, characterized in that the connection points of the gas guide device (40) with the wall (30) of the plasma source (3) are further away from the plane of the opening (31) than the first gas inlet (35a, 35b ).

15. Plasma treatment device according to one of the preceding claims, characterized in that the gas-conducting device (40) is arranged movably on the wall (30) of the plasma source (3).

16. plasma treatment apparatus according to any one of the preceding claims, characterized in that the plasma source (3) comprises a plurality of gas guide devices (40), wherein each of the Gasleitvorrichtungen (40) in a partial region of the extension of the plasma source (3) in the direction along the axis of the microwave antenna ( 32) which is different from other portions in which another one of the gas guiding devices (40) is arranged.