DE102007056138A1 - Inductively coupled micro-wave plasma cell e.g. film system, has vacuum chamber formed at end of hollow chamber, where pressure of preset value lies on side of vacuum chamber such that plasma extends from hollow chamber to vacuum chamber - Google Patents

Abstract

The cell (1) has a microwave oscillator for producing microwaves and connected with a waveguide (2) for coupling the microwaves into the waveguide, and base layer made of metal. A hollow chamber (5) is designed as a throughhole, and a gas supply (7) is connected with an end of the hollow chamber. A vacuum chamber (9) is formed at another end of the hollow chamber, and a pressure differences are formed between the ends, where the pressure of small 100 millibar lies on a side of the vacuum chamber in such a manner that a plasma extends from the hollow chamber to the vacuum chamber. Independent claims are also included for the following: (1) a system for plasma-technological processing of substrates (2) a method for coating of substrates.

Description

The The invention relates to a microwave plasma source, an arrangement of Microwave plasma sources, a plant for plasma technological processing of substrates, a method of coating substrates with a microwave plasma source and a use of microwave plasma sources with in the claims 1, 17, 25 and 27 mentioned features.

For vacuum applications There are a variety of plasma sources, including those with microwave excitation, their development by the demand for Generation of ever smaller structures with least damage to the Substrates through the plasma, after homogeneous machining of ever larger areas and is driven forward after short processing times.

in the Core is about it, one for the machining stable and optimal plasma composition to achieve and these temporally and locally to control. This goal can in principle be with arrangements of a number be achieved by miniaturized plasma sources. Another possibility consists of the interaction of different forms of discharge use, like that for example capacitively and inductively coupled discharges in modern plasma systems the case is.

The Excitation of gas discharges with microwaves is at the latest technically used since the 60s of the 20th century. In the predominant The majority of these applications will have a frequency of 2.45 GHz used. The microwave power is generated by a generator and over a waveguide arrangement fed into the actual plasma source. A typical feature of these sources is the high plasma density, due to the high frequency of the electromagnetic field can be achieved. These plasma sources become the plasma properties essentially by the external plasma parameters Pressure, power and gas composition are determined and can only be adapted to processes within these limits.

So will in the DE 198 56 307 describes a plasma jet source which can also be excited by microwaves, with which a plasma jet directed in a vacuum and focused can be produced. The bundling of the beam is presumably caused by the propagation of surface waves on the surface of the plasma jet. Such a source is particularly well suited if a substrate is to be subjected to a plasma process only on partial areas. For the excitation of the discharge, a commercial microwave source is used, the energy of which must be supplied to the plasma source via a voluminous waveguide arrangement. As a result, narrow limits are set for an advantageous arrangement of a multiplicity of plasma sources.

Arrangements of several plasma jets are also known, which are directed into a lower pressure reaction chamber. So will in DE 197 22 624 described the production of Plasmajets from a hollow cathode chamber in a process space. However, all plasma jets are powered by a generator at frequencies below 100 MHz and are not individually controllable. In US 2006/0021581 An arrangement of plasma jets excited by standing microwaves is described. The standing microwaves are generated in a common cavity. From the high-field zones of this field energy is coupled to individual gas-flowed hollow electrodes, from which then emerges a plasma jet. These plasma jets are not individually controllable. Their geometric arrangement is also determined by the field distribution of the standing microwaves.

An array of plasma sources in which each source can in principle be excited independently of all others is disclosed in US Pat DE 10 2005 002 142 A1 described. This is achieved by hollow electrodes in a substrate being individually excited by oscillators arranged on the front side of the substrate. The oscillators and the type of excitation are not described in detail. The arrangement operates at near-atmospheric pressures.

Indeed enough the level reached in the temporal and spatial control of the plasma composition not out to the constant to meet growing demands. Although the variation of the external plasma parameters such as pressure, gas composition and coupled power to very different internal plasma parameters such as ion and neutral particle densities can not always the desired conditions be set.

It Therefore, there is still a need to develop an arrangement of individually controllable, effective plasma sources with which processes in the Vacuum performed and regarding the local and temporal plasma composition can be controlled.

This object is achieved by the features of claims 1, 17, 25 and 27. There is provided a microwave plasma source comprising a waveguide, a microwave oscillator for generating microwaves, connected to the waveguide for coupling the microwaves in the waveguide, a cavity , formed as a through hole through the waveguide perpendicular to the off waveguide formation direction, a gas supply, which is connected to a first end of the cavity, a vacuum chamber, which is formed at the other second end of the cavity, wherein the waveguide is designed such that a standing wave is realized with a vibration in the region of the cavity cavity , And between the first end of the cavity on the side of the gas supply and the other second end of the cavity on the side of the vacuum chamber, a pressure difference is formed, wherein on the side of the vacuum chamber, a pressure of less than or equal to 100 mbar is applied, such that the plasma propagates from the cavity into the vacuum chamber.

The Plasma source allows a miniaturized microwave discharge or the arrangement of several miniaturized microwave discharges and their supply of Microwave power and process gases such that the possibilities the temporal and spatial Control of the plasma composition compared to the current state expanded become.

Farther is the microwave plasma source according to the invention Designed to effectively address process requirements in the etch and process industries Coating technology can be adjusted.

With Microwave cavity plasma sources with integrated oscillator can open Reason the very high excitation frequency generates higher plasma densities be, as with conventional Capillary sources in the MHz range. This allows applications in low-pressure plasma under vacuum conditions. These plasma sources can due to their low Dimensions are arranged almost arbitrarily in a plasma reactor. The novel principle of local generation required for the plasma stimulation Microwave power allows the separate control of the individual sources as well as the simultaneous ones Operation with other plasma sources.

there the cavity can have a diameter of 1mm to 10mm and can be cylindrical.

Of the Waveguide may be disposed on a base layer, wherein the cavity passes through the waveguide and the base layer as a through hole. The base layer may be metallic. Between base layer and Waveguide may be arranged an insulator layer, wherein the Cavity through the waveguide, the insulator layer and the base layer passes through, whereby the said pressure difference between the one Side of the plasma source with the base layer and the other side with the gas supply is applied.

Of the Oscillator can generate a microwave frequency above 1GHz. The oscillator may be connected to a power supply line. Between Oscillator and waveguide can be arranged a coupling line be.

Of the Pressure on the low pressure side can preferably be less than or equal to 1 mbar be. The inside of the cavity can, with the exception of a Zündspaltes, in the gas ignited will be metallized forms. The inside of the cavity may also be covered with an insulator resistant to reactive plasmas.

The Gas supply can be connected to a pipe whose interior with the cavity in the waveguide communicates. The tube is vertical arranged on the waveguide.

Of the Cavity may be formed as the interior of a pipe, which at a first end with the gas supply and at the other second end communicates with the vacuum chamber. The tube goes through the Waveguide and, if present, through the base layer and the Insulator through.

Parallel to the propagation direction of the cavity can on its sides second Be formed portions of the waveguide.

waveguides and oscillator can be formed integrated.

Further proposed is an array of microwave plasma sources comprising a plurality of waveguides; a plurality of microwave oscillators for generating and coupling microwaves in waveguides; Cavities for generating a plasma, which are formed as a through hole by waveguides perpendicular to the propagation direction of the waveguide concerned; at least one gas supply connected to a first end of the cavities; a vacuum chamber formed at the other second end of the cavities; wherein the cavities are grouped together via corresponding waveguides, that in the cavities of each group a microwave power from each one of the microwave oscillators whose number is equal to the number of groups, can be coupled, and the waveguides are formed such that a standing wave is realized with a vibration in the region of a corresponding cavity, and between the first ends of the cavities on the side of the at least one gas supply and the other second ends of the cavities on the side of the vacuum chamber, a pressure difference is formed, wherein on the side of the vacuum chamber Pressure of less than or equal to 100 mbar is applied, such that the plasma from the cavity into the Va vacuum chamber spreads.

The Groups of waveguides with cavities may be arranged in series. The waveguides can have a deviating from a straight line geometry. A waveguide may have a curved shape between two adjacent cavities. A waveguide may be sinusoidal be. The waveguides can arranged with sections partly parallel to the axis of the cavity be. Several gas supplies can be arranged. The different gas supplies can be different process gas mixtures different cavities respectively, the cavities separately so supplied with different electrical power are formed that specifically plasma compositions produced are.

Of Furthermore, a plant for plasma technology processing of substrates consisting of at least one plasma source according to the invention comprising a waveguide, a microwave oscillator for generating of microwaves connected to the waveguide for coupling the Microwaves in the waveguide, a cavity formed as Through hole through the waveguide perpendicular to the formation direction of the waveguide, a gas supply connected to a first end of the cavity connected to a vacuum chamber at the other second end of the Cavity is formed, wherein the waveguide is formed is that a standing wave with an antinode in the area the cavity is realized, and between the first end the cavity on the side of the gas supply and the other second End of the cavity on the side of the vacuum chamber, a pressure difference is formed, wherein on the side of the vacuum chamber, a pressure of less than or equal to 100 mbar, so that the plasma from the cavity into the vacuum chamber propagates; a vacuum chamber; an evacuation system; a substrate support; and facilities for controlling gas flows into the plasma source or into the vacuum chamber.

When Process gases can inorganic and organic silanes, hydrocarbon compounds, organometallic compounds as well as hydrogen, oxygen or nitrogen-containing gases are used.

Further is given a method for coating substrates, with a plasma source comprising a waveguide, a microwave oscillator for generating microwaves, connected to the waveguide for Coupling the microwaves into the waveguide, a cavity, formed as a through hole through the waveguide perpendicular to Training direction of the waveguide, a gas supply, with a connected to the first end of the cavity, a vacuum chamber, the is formed at the other second end of the cavity, wherein the Waveguide is designed such that a standing wave with an antinode is realized in the region of the cavity, and between the first end of the cavity on the side the gas supply and the other second end of the cavity on the Side of the vacuum chamber, a pressure difference is formed, wherein on the side of the vacuum chamber a pressure of less than or equal to 100 mbar is applied, such that the plasma from the cavity into the vacuum chamber spreads; the method comprising the steps of: forming a Pressure difference between the one end of the cavity and the other second end of the cavity; Admixture of the layer-forming Gases outside the plasma source over the gas supply; Generation of a standing microwave with a vibration abdomen in the cavity by means of the oscillator; Ignition of the gases supplied to the cavity through the standing microwave; Propagation of the resulting plasma into the vacuum chamber as a result of said pressure difference.

The The method may further comprise the step of grouping a plurality cavities over corresponding Include waveguide groups, such that each in the cavities of a Group a microwave power from each a microwave oscillator, whose number is equal to the number of groups, can be coupled.

The The method may further comprise the steps of: supplying various Process gas mixtures over a plurality of gas supplies to different cavities, separate Supply of cavities with different electrical powers, so targeted plasma compositions can be generated.

In conclusion is a use of the plasma source according to one of claims 1 to 16, together with an inductively coupled plasma source, to improve stability and the ignition behavior the inductively coupled plasma source and / or to reduce Electron temperature and plasma potential.

Further preferred embodiments of the invention will become apparent from the others, in the subclaims mentioned features.

The Invention will be described below in embodiments with reference to FIG associated Drawings explained. Show it:

1 A side view of a plasma cell according to the invention with local microwave oscillator;

2 A plan view of the plasma cell of the invention 1 ;

3 A side view of another embodiment of the plasma cell according to the invention;

4 A side view of a third embodiment of the plasma cell according to the invention;

5 A side view of an embodiment of a plasma source array with a plurality of plasma cells with a separate waveguide;

6 A plan view of an embodiment of a plasma source arrangement with a plurality of plasma cells with a separate waveguide 5 ;

7 An embodiment of a plasma source array having a plurality of uniform waveguide plasma cells;

In 1 and 2 is the principle of the microwave plasma source with integrated oscillator shown. The plasma cell 1 in the side view of 1 and the top view of 2 consists of a metallic base layer 4 , an insulator 3 , a waveguide 2 a cavity 5 , a coupling line 11 , DC power supply lines 12 and an insulating gas supply 7 , The plasma cell 1 is designed as a layer system. The lowest layer forms the metallic base layer 4 , On the base layer 4 is a layer of an insulator 3 applied. On the insulator 3 is then located as the top layer of the waveguide 2 ,

Through the layer system of the plasma cell 1 a cavity goes 5 perpendicular to the propagation direction of the respective layers, ie from one side of the plasma cell through the waveguide 2 , through the insulator 3 , through the metallic base layer 4 through to the other side of the plasma cell 1 , The cavity 5 can be easily formed as a hole through the layer system. The cavity 5 is vacuum-sealed and the underside of the plasma cell 1 with the metallic base layer 4 is vacuum-tightly connected to a vacuum chamber. On the top of the plasma cell 1 So on the waveguide 2 , is a pipe 6 arranged so that its hollow interior with the cavity 5 is communicatively connected. The hollow interior 7 of the pipe 6 serves as a gas supply. The tube is preferably perpendicular to the layer structure of the plasma cell 1 formed, that is perpendicular to the propagation direction of the waveguide 2 , In the cavity 5 is a spark gap 8th indicated, in which the gas is ignited.

While the base layer 4 and the insulator 3 are configured over the entire surface, is the waveguide 2 only around the cavity 5 trained around. Its length is at the desired resonant frequency for igniting the gas in the cavity 5 Voted.

By connecting the bottom of the plasma cell 1 with a vacuum chamber can below the outlet opening 10 of the cavity 5 preferably pressures of less than 100 mbar are generated, for example when 500 sccm argon through the cavity 5 flow. Above the cavity 5 In this case, a pressure difference is built up, so that, for example, the pressure at the upper end of the gas supply 7 at least twice as high as in the vacuum chamber 9 ,

On the top of the plasma cell 1 is like in 2 shown an oscillator circuit 12 arranged. This is via the supply lines 14 supplied with direct current. In the 12 generated microwave power is transmitted through a coupling line in the waveguide 2 coupled. The waveguide preferably has a length which corresponds to half the wavelength of the oscillation generated by the oscillator. The waveguide as part of the resonator determines the oscillation frequency. The oscillator ignites with appropriate microwave power and certain flow and pressure conditions in the hollow electrode 11 a plasma that is essentially driven by the gas flow into the vacuum chamber. Here is the waveguide 2 designed so that the standing wave generates a vibration at the site of the cavity.

The resulting plasma can be used alone or in conjunction with in the vacuum chamber fed working gases for plasma-assisted coating, Functionalization or etching processes used become.

Typically, powers below 10 W are sufficient to maintain the plasma. Characteristic of the plasma in the vacuum chamber at a distance of 20 mm from the outlet 10 is a low electron energy of the order of 0.1 eV, which is advantageous in the processing of sensitive substrates.

Thus, therefore, every cavity 5 in which a gas is ignited by a standalone waveguide 2 surrounded by an oscillator 12 for generating a microwave radiation via a coupling line 11 connected is. Each of these arrangements can therefore be controlled individually.

Another embodiment of the plasma cell is in 3 shown. The gas and the plasma generation zone are located here completely in a pipe 6 , which preferably consists of ceramic, for example of aluminum oxide. As a result, the contact of the plasma can be avoided with inappropriate wall material. The pipe 6 So goes completely through the layer system of waveguides 2 , Insulator 3 and base layer 4 therethrough. In other words, the hollow interior of the pipe 6 now forms the cavity 5 in which the plasma is ignited.

Another embodiment of the plasma cell is in 4 shown as a side view. Here, the field of the waveguide is guided along the plasma in order to increase the coupling efficiency of the microwave into the plasma. The waveguide 2 So it's not just on the insulator 3 arranged but surrounds the cavity 5 or the pipe 6 perpendicular to the propagation direction of the waveguide 2 in 1 and parallel to the flow direction of the gas indicated by the arrow in the gas supply 7 , The waveguide 2 thus points along the longitudinal axis of the tube 6 other areas 15 on, with the areas 15 perpendicular to the propagation direction of the waveguide 2 are. The areas 15 of the waveguide 2 contact the wall of the pipe 6 on one side and the insulator 3 on the other hand, so they are in the insulator 3 embedded. Here is the cavity 5 again through the pipe 6 of the 3 educated. Of course, in this arrangement, the 4 also a combination of cavity 5 and pipe 6 of the 1 possible.

On the basis of 1 to 4 are easily imagined further embodiments that operate on the same principles.

So that large-area substrates can be processed, is in 5 in a side view and in 6 in a plan view of an arrangement of a plurality of plasma cells according to the invention 1 out 1 shown.

In 5 and 6 are four juxtaposed plasma cells 1 designated with 1' . 1'' . 1''' and 1'''' shown.

As in 6 As can be seen, the plasma cells 1 arranged in rows, here by way of example in three rows. Each row has a supply line 16 to power each oscillator 12 , It is particularly advantageous that each plasma cell 1 the arrangement can be controlled individually. In particular, the plasma cells can be arranged geometrically in such a way that the uniformity of etching or coating processes is optimized. Furthermore, it is possible to design the power supply of the individual plasma cells so that the uniformity of etching or coating processes is further increased.

In all embodiments, the cavities 5 so over appropriate waveguides 2 be grouped into groups, each in the cavities 5 a group of microwave power from each one of the microwave oscillators 12 , whose number is equal to the number of groups, can be coupled. Any groups can be formed.

Also, in all embodiments, different gas supplies 7 be provided. The gas supplies 7 Different process gas mixtures can have different cavities 5 feed, with the cavities 5 are designed to be supplied separately with different electrical power so that specifically plasma compositions can be generated.

In 7 a further embodiment for the arrangement of plasma cells is simplified schematically shown. In a common waveguide 2 There are several cavities 5 at locations where waves of a standing wave can be generated in the waveguide by an oscillator located on the array. Preferably, the waveguide has a length corresponding to an integral multiple of half the wavelength of the excited vibration. The waveguide 2 itself is formed sinusoidal or curved or meandering.

In the 7 illustrated special shape of the waveguide 2 allows a denser packing of the plasma cells and thus an even more miniaturized arrangement. For the plasma cells themselves one of the in the 1 to 4 illustrated embodiments and an embodiment derived therefrom into consideration.

It can be seen that the arrangement can be varied depending on the etching or coating process. In other words, the plasma sources 1 do not have to be in rows, but can also be arranged arbitrarily.

The cavity 5 can be formed in all embodiments as a capillary. On its low-pressure side, a flow can occur at supersonic speed.

Of the Zündgap can be on the high pressure side.

One or more plasma sources 1 According to the invention can also be used together with an inductively coupled plasma source to improve the ignition performance of the inductively coupled plasma source. In particular, the use with an inductively coupled plasma source to reduce the electron temperature and the plasma potential into consideration.

The plasma sources according to the invention 1 can be traversed by different process gas mixtures.

she can also separately supplied with different electrical power so that targeted plasma compositions for etching and Coating can be produced with the conventional Technology are unreachable.

When Process gases usually all come in technological low-temperature plasmas used gases, such as e.g. chlorine-containing or fluorine-containing Compounds, noble gases, molecular gases, hydrocarbons, Silanes and organometallic compounds and mixtures of these Gases.

Advantageously, the present invention enables even an ignition of gases when on one side of the plasma source 1 with the vacuum chamber 9 a low pressure less than the atmospheric pressure, preferably less than 100 mbar, more preferably less than 1 mbar is present. The gas or the inflamed plasma is from the gas supply 7 from one side of the plasma source 1 , on which a higher pressure than that on the side of the vacuum chamber 9 prevails, led by the pressure difference in the vacuum chamber for machining surfaces. This is done with microwaves, the gas in the cavity 5 in the waveguide 2 ignited.

1

plasma source

2

waveguides

3

insulator layer

4

base layer

5

cavities

6

pipe

7

gas supply

8th

spark gap

9

vacuum chamber

10

outlet opening

11

coupling line

12

oscillator

13

coupling line

14

power supply

15

sections

16

supply

Claims (30)

Microwave plasma source ( 1 ), comprising - a waveguide ( 2 ), - a microwave oscillator ( 12 ) for generating microwaves, connected to the waveguide ( 2 ) for coupling the microwaves in the waveguide ( 2 ), - a cavity ( 5 ) formed as a through hole through the waveguide ( 2 ) perpendicular to the formation direction of the waveguide ( 2 ), - a gas supply ( 7 ) connected to a first end of the cavity ( 5 ), - a vacuum chamber ( 9 ), which at the other second end of the cavity ( 5 ), wherein the waveguide ( 2 ) is formed such that a standing wave with a vibration belly in the region of the cavity ( 5 ) is realized, and between the one end of the cavity ( 5 ) on the side of the gas supply ( 7 ) and the other second end of the cavity ( 5 ) on the side of the vacuum chamber ( 9 ) a pressure difference is formed, wherein on the side of the vacuum chamber ( 9 ) is applied a pressure of less than or equal to 100 mbar, such that the plasma from the cavity ( 5 ) in the vacuum chamber ( 9 ) spreads. A plasma generator according to claim 1, wherein the cavity ( 5 ) has a diameter of 1mm to 10mm. Plasma source according to claim 1 or 2, wherein the cavity ( 5 ) is cylindrical. A plasma generator according to claim 1, wherein the waveguide is mounted on a base layer ( 4 ) is arranged and the cavity ( 5 ) through the waveguide ( 2 ) and the base layer ( 4 ) passes as a through hole. A plasma source according to claim 4, wherein between base layer ( 4 ) and waveguides ( 2 ) an insulator layer ( 3 ) is arranged and the cavity ( 5 ) through the waveguide ( 2 ), the insulator layer ( 3 ) and the base layer ( 4 ), whereby said pressure difference between the one side of the plasma source ( 1 ) with the base layer ( 4 ) and the other side with the gas supply ( 7 ) is present. Plasma source according to one of the preceding claims, wherein the oscillator ( 12 ) generates a microwave frequency above 1 GHz. Plasma source according to claim 4, wherein the base layer ( 4 ) is metallic. Plasma source according to one of the preceding claims, wherein the pressure on the low pressure side is less than or equal to 1 mbar. Plasma source according to one of the preceding claims, wherein the inside of the cavity ( 5 ) with the exception of a spark gap ( 8th ), in which the gas is ignited, is metallized. Plasma source according to one of claims 1 to 8, wherein the inside of the cavity ( 5 ) is covered with an insulator resistant to reactive plasmas. Plasma source according to one of the preceding claims, wherein the gas supply ( 7 ) with a pipe ( 6 ), whose interior is connected to the cavity ( 5 ) in the waveguide ( 2 ) communicates. Plasma source according to one of claims 1 to 10, wherein the cavity ( 5 ) as the interior of a pipe ( 6 ), which at a first end with the gas supply ( 7 ) and at the other second end with the vacuum chamber ( 9 ) communicates. Plasma source according to one of the preceding claims, wherein parallel to the propagation direction of the cavity ( 5 ) on its sides second sections ( 15 ) of the waveguide ( 2 ) are formed. Plasma source according to one of the preceding claims, wherein the oscillator ( 12 ) with a power supply ( 14 ) connected is. Plasma source according to one of the preceding claims, wherein between oscillator ( 12 ) and waveguides ( 2 ) a coupling line ( 13 ) is arranged. Plasma source according to one of the preceding claims, wherein waveguides ( 2 ) and oscillator ( 12 ) are integrated. Arrangement of microwave plasma sources, comprising - a plurality of waveguides ( 2 ); A plurality of microwave oscillators ( 12 ) for the generation and coupling of microwaves in waveguides ( 2 ); - cavities ( 5 ) for generating a plasma, which is a through-hole through waveguides ( 2 ) perpendicular to the propagation direction of the waveguide in question ( 2 ), - at least one gas supply ( 7 ), which are connected to a first end of the cavities ( 5 ), - a vacuum chamber ( 9 ) located at the other second end of the cavities ( 5 ), wherein the cavities ( 5 ) so via corresponding waveguide ( 2 ) are grouped into groups that each into the cavities ( 5 ) a group a microwave power from each one of the microwave oscillators ( 12 ), whose number is equal to the number of groups, can be coupled in, and the waveguides ( 2 ) are formed such that a standing wave with a vibration belly in the region of a corresponding cavity ( 5 ) is realized, and between the first ends of the cavities ( 5 ) on the side of the at least one gas supply ( 7 ) and the other second ends of the cavities ( 5 ) on the side of the vacuum chamber ( 9 ) a pressure difference is formed, wherein on the side of the vacuum chamber ( 9 ) is applied a pressure of less than or equal to 100 mbar, such that the plasma from the cavity into the vacuum chamber ( 9 ) spreads. A microwave plasma source assembly according to claim 17, wherein said groups of waveguides ( 2 ) with cavities ( 5 ) are arranged in series. A microwave plasma source arrangement according to claim 17 or 18, wherein the waveguides ( 2 ) have a deviating from a straight line geometry. Microwave plasma source arrangement according to one of claims 17 to 19, wherein at least one waveguide ( 2 ) between two adjacent cavities ( 5 ) has a curved shape. A microwave plasma source arrangement according to claim 17 or 18, wherein at least one waveguide ( 2 ) is formed sinusoidal. A microwave plasma source arrangement according to any one of claims 17 to 21, wherein the waveguides ( 2 ) with sections ( 15 ) partially parallel to the axis of the cavity ( 5 ) are arranged. Microwave plasma source arrangement according to one of claims 17 to 22, wherein a plurality of gas feeds ( 7 ) are arranged. A microwave plasma source assembly according to claim 23, wherein the different gas supplies ( 7 ) different process gas mixtures different cavities ( 5 ), the cavities ( 5 ) are designed so that they can be supplied separately with different electrical powers in such a way that plasma compositions can be generated in a targeted manner. Plant for plasma technological processing of substrates, consisting of - at least one plasma source ( 1 ) according to one of claims 1 to 16, - a vacuum chamber ( 9 ); - an evacuation system; A substrate support; and - devices for regulating gas flows into the plasma source ( 1 ) or in the vacuum chamber ( 9 ). Plant according to claim 25, wherein the process gases are inorganic and organic silanes, hydrocarbon compounds, organometallic compounds and hydrogen, oxygen or nitrogen containing gases used become. A method of coating substrates with a plasma source according to any one of claims 1 to 16, comprising: - forming a pressure difference between the one end of the cavity ( 5 ) and the other second end of the cavity ( 5 ); - admixture of the layer-forming gases outside the plasma source ( 1 ) via the gas supply ( 7 ); Generation of a standing microwave with a vibration abdomen in the cavity ( 5 ) by means of the oscillator ( 12 ); - Ignition of the cavity ( 5 ) supplied gases through the standing microwave; - Propagation of the resulting plasma in the vacuum chamber as a result of said pressure difference. The method of claim 27, further comprising the step of combining a plurality of cavities ( 5 ) via corresponding waveguides ( 2 ) into groups, such that in each case in the cavities ( 5 ) a microwave power from a respective microwave oscillator ( 12 ), whose number is equal to the number of groups, can be coupled in. The method of claim 27 or 28, further comprising the steps of: - supplying different process gas mixtures via a plurality of gas supplies ( 7 ) to different cavities ( 5 ), - separate supply of the cavities ( 5 ) with different electrical powers, so that targeted plasma compositions can be generated. Use of the plasma source ( 1 ) according to one of claims 1 to 16 together with an inductively coupled plasma source for improving the stability and the ignition behavior of the inductively coupled plasma source and / or for reducing the electron temperature and plasma potential.