DE102014011933A1 - Plasma treatment apparatus and method for surface treatment of substrates - Google Patents

Abstract

The present invention relates to a process for the surface treatment of substrates and a corresponding plasma treatment apparatus, comprising - a plasma treatment chamber (12) in which at least a first substrate holder (14) and a second substrate holder (16) are arranged, wherein the first substrate holder (14) in Direction of its surface normal (N) spaced from the second substrate holder (16) is arranged and wherein the first and the second substrate holder (14, 16) on opposite sides of a plasma region (18) are arranged, - at least one of the plasma region (18) in the circumferential direction enclosing Excitation coil (20) for excitation of a plasma (19) in the plasma region (18), - a first voltage supply (1), which is connected to the first substrate holder (14), - a second voltage supply (2), which with the second substrate holder ( 16), and with - a third voltage supply (3) connected to the excitation coil (20 ), wherein at least the phase (P1) of the first voltage supply (1) is coupled to the phase (P2) of the second voltage supply (2).

Description

Technical area

The present invention relates to a plasma processing apparatus and a related method for surface treatment of planar substrates. In particular, the invention relates to a device and a method for simultaneously treating a plurality of substrates, which can be arranged on opposite sides of a plasma region in a plasma treatment chamber.

Devices and methods for plasma assisted processing of substrates, particularly for etching or coating substrate surfaces, are well known in the art. For uniform and full-surface application of thin layers on substrates u. a. chemical Dampfabscheideverfahren, in particular plasma-enhanced chemical vapor deposition method, so-called PECVD method (plasma-enhanced chemical vapor deposition) used. For this purpose, one or more substrates are arranged in a plasma treatment chamber into which at least one reaction gas, or a gas mixture tuned to the coating or an etching process, is introduced while maintaining predetermined pressure and temperature ranges.

This is at least partially in a plasma state by supplying electromagnetic energy, such as by inductive or capacitive coupling of a high-frequency excitation. From the DE 10 2011 013 467 A1 is the most efficient use of a plasma source known. Herein, a vacuum chamber is disclosed, in which at least two substrates can be arranged facing each other at a predetermined distance and with their surfaces to be treated, and further wherein a plasma generating device is provided, which has at least one excitation coil for inductive excitation of at least one plasma located between the substrates.

From the JP 2007-150012 A Furthermore, an etching method is known in which substrate holders arranged opposite to a plasma are each coupled to an RF generator. The voltage of the respective electrodes, that is, the voltage at the substrate holders is measured here, and the high-frequency power of the RF generators is set to an average value of the voltages of the two electrodes.

This results inevitably in different voltages or different voltage potentials at the electrodes or substrate holders, which lead to at least slightly different surface treatment processes of the substrates, which are arranged on opposite sides of the plasma.

It is therefore an object of the present invention to provide a plasma treatment apparatus for the simultaneous treatment and the most uniform and similar surface treatment of several, with their surfaces facing each other substrates. It is a further object to provide a method for the correspondingly simultaneous surface treatment of at least two substrates. The present invention should be particularly suitable for the most uniform and high-quality coating of multiple substrates.

Invention and advantageous embodiments

According to a first aspect of the invention, a plasma treatment apparatus for surface treatment of a plurality of substrates is provided in this respect. The plasma treatment apparatus has a plasma treatment chamber in which at least one first substrate holder and a second substrate holder are arranged or can be arranged.

The first substrate holder is arranged spaced apart in the direction of its surface normal to the second substrate holder. The first and the second substrate holder are furthermore arranged on opposite sides of a plasma region, in which the plasma to be generated in the plasma treatment chamber is essentially located during operation of the plasma treatment device.

Typically, the first and second substrate holders are disposed approximately parallel to one another and on different or opposite sides of the plasma region. Considered in the direction of the surface normal of the first substrate holder, the first and the second substrate holder may be arranged substantially overlapping or overlapping. However, other arrangements of first and second substrate holders are also conceivable, for example such that the plane of the first substrate holder and the plane of the second substrate holder extend at a predetermined angle greater than 0 ° to one another.

The plasma treatment device further has at least one excitation coil enclosing the plasma region in the circumferential direction for exciting a plasma in the plasma region. The excitation coil is used in particular for inductive excitation of the plasma within the plasma treatment chamber. The excitation coil can in this case be arranged in particular outside the actual plasma treatment chamber, provided that corresponding outer walls of the plasma treatment chamber for the electromagnetic, in particular inductive excitation of the gases located within the plasma treatment chamber is permeable. The plasma treatment chamber may have, for example, a circumferential wall section made of quartz glass or comparable electromagnetically permeable materials.

The plasma processing apparatus is further provided with a first power supply connected to the first substrate holder. The plasma processing apparatus is further provided with a second power supply connected to the second substrate holder, and the plasma processing apparatus further includes a third power supply connected to the excitation coil. By means of first and second voltage supply and a corresponding voltage application of the first and second substrate holders, the plasma ion stream provided for coating purposes of the substrates may be modified or reinforced in the direction of the substrate surfaces.

While the first and second power supplies are commonly referred to as bias voltages for the substrate holders and, for example, for the typically electrically non-conductive substrates, the third power supply provides high frequency electrical power for plasma generation.

As a result, in particular in the case of a plasma-assisted coating process, the layer growth on the one hand accelerates, on the other hand, however, the structure of the layer can also be positively influenced and changed. By applying a voltage potential, in particular a corresponding electrical power to the opposite substrate holders, ions located in the plasma can be accelerated in the direction of the substrate surfaces to be treated, so that, for example, a desired intrinsic and mechanical stress can be generated within the layer.

It is further provided for the plasma processing apparatus that at least the phase of the first power supply is coupled to the phase of the second power supply. By a phase coupling of the first and second voltage supply same voltage potentials can be realized at the first and second substrate holder, so that substantially identical electrical boundary conditions can be provided for both substrate holder, and thus for at least two substrates detachably attached to the respective substrate holders.

In this way, the substrates on both sides of the plasma and on different opposite sides of the plasma can be arranged and which experience a quasi-identical surface treatment, in particular a surface coating which is far more identical in terms of its physical properties and quality.

According to a further embodiment, it is further provided that the phase of the third power supply is coupled to at least one of the phases of the first or second power supply. In this way, not only can a fixed phase relationship between the first and second power supplies in the operation of the plasma processing apparatus, but also a fixed phase relationship can be provided between all three power supplies.

By virtue of the fact that all the phases of the first voltage supply, second voltage supply and third voltage supply can be coupled to one another, not only identical bias voltages or corresponding voltage potentials can be set on the first and second substrate holders, but it can also be an optimization of the power output with respect to an electrical bias coupled into the substrate holders Be made possible.

By coupling the phase of the first voltage supply with the phase of the second voltage supply, in particular by variably and continuously adjusting a relative phase position between first and second voltage supply, symmetrical and identical plasma and surface treatment conditions can be set on the first and second substrate holders. By coupling the phase of the third voltage supply, in particular by modifying the phase position of the first and second voltage supply relative to the phase of the third voltage supply, a voltage potential at the first and second substrate holder can be maximized while the electrical power coupled to the first and second substrate holders remains constant.

In this way, ion bombardment from the plasma to the substrates arranged on the substrate holders can ultimately be set independently of other coating parameters.

In accordance with a further embodiment, at least one of the power supplies has a high-frequency (HF) generator, which is coupled to the two remaining power supplies. For the phase coupling of the first, second and third voltage supply with each other, it is sufficient in principle, if only one Power supply, such as one or more coupling cable, is phase-coupled to the other two power supplies. In that regard, it can be provided that, for example, the first power supply is coupled to the third power supply, and that the second power supply is also coupled to the third power supply.

A phase coupling of the first and third voltage supply and a phase coupling of the second and third voltage supply implicitly also causes a phase coupling between the first and second voltage supply. The HF generator can be configured, for example, as a so-called master oscillator or as a clock signal generator. By means of the phase coupling, a frequency or clock signal of the at least one HF generator can be transmitted to the two further power supplies, so that they merely adapt the frequency or clock signal to be received with regard to its phase and amplitude as required.

However, at least two of the three power supplies do not require their own high frequency generator. About the phase-synchronous coupling of the three power supplies to each other, it is sufficient if only one power supply is equipped with an RF generator for generating a corresponding high-frequency signal. The apparatus required can thus be reduced in an advantageous manner.

According to a further embodiment it is provided that each of the three power supplies each having an amplifier, wherein the respective amplifiers are independently adjustable and adjustable as needed. In this way, starting from a common frequency or clock signal, different supply voltages of the excitation coil and the at least first and second substrate holders can be supplied as needed.

According to a further embodiment, it is further provided that the phase of the first voltage supply is selectively adjustable and fixable relative to the phase of at least one of the two remaining power supplies, that is to the phase of the second power supply and / or the phase of the third power supply. The selective and independent adjustability of the phases of the individual power supplies is advantageous for forming symmetric coating conditions on the opposed substrate holders as well as for maximizing power yield.

According to a further embodiment, it is provided that also the phase of the second voltage supply relative to the phase of at least one of the two remaining power supplies, that is to the phase of the first power supply and / or the phase of the third power supply is selectively adjustable and fixable. In this way, any adjustability and fixability of the phases of the power supplies or the bias voltages of the substrate holder and the operating voltage of the excitation coil can be achieved.

In this case, it is provided in particular to set the relative phase positions between the first and the second voltage supply as well as with respect to the third voltage supply and then to fix those phase positions for the further operation of the plasma treatment device relative to one another.

According to a further embodiment of the plasma treatment device, this is designed with a control for the automatic adjustment of a relative phase position between the first and the second voltage supply such that the same supply potential of the first and second voltage supply equal voltage potentials at the first and the second substrate holder form. In particular, it is conceivable that a relative phase position not equal to 0 between the first and the second voltage supply can be set to form the same voltage potentials on the first and the second substrate holder.

The electrical connection of the first voltage supply to the first substrate holder, or the electrical connection of the second voltage supply to the second substrate holder possibly has cables of different lengths and an impedance matching, which under real conditions cause, for example, despite the same phase angle at the first and the second voltage supply ultimately different phase positions on the substrate holders relevant for the coating are present.

By measuring the voltage potentials that actually form on the substrate holders, matching and adjustment of the phase position between the first and second voltage supply can be set and selected such that the voltage potentials at the first and second substrate holders are substantially equal. The adaptation of the voltage potentials on the two substrate holders can be effected independently of a change in the supply power of the first and second power supplies.

This allows for the formation of substantially symmetrical and identical surface treatment environment parameters on the first and second substrate holders oppositely arranged therewith without this significant influence or feedback on the set bias power of the power supplies or the substrate holder. Symmetrical surface treatment requirements may be provided and adjusted in this manner regardless of the supply power of the first and / or second power supply.

According to a further development, it is further provided that the control for the automatic setting of a relative phase position between the third voltage supply and one of the first and second voltage supply is designed in such a way that a maximum voltage potential is formed on one of the first and second substrate holders. By changing the phase position of at least one of the first and second voltage supply relative to the phase of the third voltage supply, in particular the median or mean value of the voltage potential forming on the respective substrate holder can be changed.

Insofar, it may be provided to initially select the relative phase position between one of the first and second voltage supply relative to the third voltage supply for maximizing a voltage potential forming at the respective substrate holder and thereafter adjusting the phase of the other of the first and second voltage supply in such a way that the first and form substantially equal voltage potentials at the second substrate holder.

In this way, the power output of the electrical supply of the first and second substrate holders can be maximized. If, for example, a bias power of the first and second power supply to be changed, this is easily possible and almost without readjustment in compliance with the already set fixed phase relationships between the first, second and third power supply. In summary, the phase coupling of the first, second and third voltage supply makes it possible to provide substantially identical plasma treatment requirements for the opposite substrate holders and to adjust a bias power or bias supply of the substrate holder as required independently of a plasma power.

According to a further aspect, the invention further relates to a method for the simultaneous surface treatment of at least two substrates by means of a previously described plasma treatment apparatus. In this case, a relative phase position between the first and the second voltage supply is set in such a way that identical voltage potentials are formed on the first and the second substrate holder with the same supply power of the first and second voltage supply.

According to a further embodiment of the method, it is further provided that the phase of one of the first and second power supply is coupled to the phase of the third power supply and fixed thereto. The phase of the other of the first and second voltage supply is then varied until the same voltage potentials are formed at the first and at the second substrate holder.

For this purpose, it is in particular provided to measure the voltage potentials actually forming on the substrate holders and to keep at least one of the phases of the first and second voltage supply constant while changing the phase of the other of the first and second voltage supply until the voltage potentials at the first and second voltage supply are changed second substrate holder are substantially equal.

To that extent, by adapting and modifying the relative phase position between first and second voltage supply, substantially identical surface treatment conditions can be provided on the substrates provided on opposite sides of the plasma. In that regard, for example, be applied in this way on the substrates layers are largely identical and have identical layer properties.

According to a further refinement of the method, it is further provided that the phase of one of the first and second voltage supply is varied relative to the phase of the third voltage supply until an absolute maximum voltage potential is formed on the first and second substrate holders, which are on the first and second substrate holders is the same size. It can be provided, for example, to keep the phase of the first power supply constant and to vary the phase of the second power supply by a certain amount relative to the phase of the third power supply and finally to fix it. With the newly selected phase of the second voltage supply, the first phase can then be varied over the entire phase space, for example.

Typically, there are two phase angles or relative phase differences between the first and second phases in which the voltage potential across the first and second substrate holders is substantially equal. Then it can be provided in a further step, for example, to keep the phase of the first power supply repeatedly constant and the phase the second voltage supply again to change by a certain predetermined amount.

Thereafter, the phase of the second power supply is then to be kept constant, while the phase of the first power supply is varied again over the entire phase space. Once again, at least two phase angles result, in which the same voltage potentials are present at the first and second substrate holders. The magnitude of those identical voltage potentials is then compared to the magnitude of the previously determined voltage potentials.

This procedure can be carried out iteratively until an absolute maximum voltage potential is achieved across the entire adjustable phase space between the first and second phase with respect to the third phase, which voltage is the same on both substrate holders. In this way, maximizing the power yield can be achieved without altering the electrical power coupled into the substrate holders. The plasma treatment device can be operated in this way particularly efficient and energy-saving.

On the basis of the voltage potentials formed on the substrate holders, corresponding ion current is produced if a plasma has been ignited in the plasma region of the plasma treatment chamber. In order to change the voltage potential as well as to change the resulting ion current, it is generally provided that the bias powers which can be injected into the substrate holders by means of first and second voltage supply can be changed to the same extent on first and second substrate holders as required.

In short, it can be provided in particular to completely scan the entire three-dimensional phase space of the three phases P1, P2 and P3 in order thereby to determine those relative phase positions between first and second voltage supply and between third and one of first and second voltage supply, in which an identical and maximum voltage potential Vmax abuts the first and second substrate holders.

It should be noted at this point that the described method relates in particular to an intended use of the plasma treatment device described above. In that regard, all the features, advantages and properties described for the plasma treatment apparatus also apply in the same manner to the method; and vice versa.

Brief description of the figures

Further objects, features and advantageous embodiments are described in the following description of an embodiment with reference to the drawings. Hereby show:

1 a schematic representation of the plasma treatment apparatus,

2 a diagram of the voltage potentials at the first and second substrate holder for a fixed predetermined phase angle of the first voltage supply via the variation of the phase angle of the second voltage supply,

3 one of the 2 corresponding diagram, but with an altered fixed phase of the first power supply,

4 an exemplary representation of the relationship between an applied voltage potential and a stress acting in the plane of the substrate layer stress in a coating process of the plasma treatment apparatus,

5 the qualitative relationship between the respectively on the first and second power supply separately adjustable bias power and the resulting voltage potential on the substrate holder and

6 a flowchart of the method for simultaneous surface treatment of at least two substrates by and by adjusting the relative phase angle between the first, second and third power supply.

Detailed description

In 1 is a plasma treatment device 10 with a plasma treatment chamber 12 in which at least two substrate holders, namely a first substrate holder 14 and a second substrate holder 16 are arranged opposite one another. At the substrate holders 14 . 16 are on the sides facing each at least one, possibly even more substrates 4 . 6 detachably arranged.

The first substrate holder 14 is in this case with respect to its surface normal N spaced from the second substrate holder 16 arranged. Relative to the direction of the surface normal N and perpendicular to the surface normal N are first and second substrate holders 14 . 16 Preferably, overlapping or overlapping arranged so that they have a plasma region therebetween 18 in which one plasma 19 is bildbar, laterally and opposite narrow at least partially.

In a space between the substrate holders 14 . 16 , which optionally over the outer edges of the substrate holder 14 . 16 is at least one rotating excitation coil 20 provided by means of which a plasma 19 in the plasma area 18 can be generated. Inside the plasma treatment chamber 12 are also largely symmetrical to the substrate holders 14 . 16 as well as the plasma area 18 two also in the direction of the surface normal N spaced gas inlets or gas distributor 15 . 17 arranged.

By means of these, the reaction gases provided for coating or for other surface treatment can be introduced into the plasma treatment chamber 12 introduced and supplied for the plasma process. The plasma treatment chamber 12 is further with a vacuum pumping device 34 coupled gas-conducting or media leading, so that provided for the plasma-assisted surface treatment process pressure level within the plasma treatment chamber 12 is adjustable.

The vacuum pumping device 34 For example, a turbomolecular pump or even a Roots pump as well as any desired combinations of such pumps may have a required volume flow of the reaction gases within the plasma treatment chamber 12 maintain.

In the 1 schematically shown plasma treatment apparatus is particularly for coating on the substrate holders 14 . 16 held substrates 4 . 6 provided and designed accordingly. To improve the quality of the coating on the substrates 4 . 6 as well as for accelerating a coating process is further provided, the substrate holder 14 . 16 each to apply a bias voltage, so that in each case a voltage potential V1, V2 at the first and the second substrate holder 14 . 16 forms.

The provision of a voltage potential, in particular a negative bias voltage, to the substrate holders 14 . 16 , leads to an increase of an ion current from the generated plasma 19 towards the plasma 19 facing surface of the substrates 4 . 6 , In this way, an intrinsic layer stress can be applied to the substrate 4 . 6 can be adjusted specifically forming layer. Furthermore, the quality, the goodness and the uniformity of the on the substrates 4 . 6 be increased and improved layer forming.

In that regard, the first substrate holder 14 with a first own power supply 1 , the second substrate holder 16 with a second power supply 2 Mistake. In addition, of course, the excitation coil 20 with its own power supply, namely with a third power supply 3 electrically coupled. It is provided according to the embodiment of the invention, in particular, that the phase P1 of the first power supply is coupled to the phase P2 of the second power supply.

In that regard, a fixed phase position between the voltage of the first power supply 1 and the voltage of the second power supply 2 realizable. It is provided in particular that the phase position of the first and second power supply 1 . 2 can be varied and fixed relative to one another. Due to the adjustability of at least one of the first and second phases P1, P2, the relative phase relationship between the first and second voltage supply 1 . 2 be changed and modified as desired, so that in particular equal voltage potentials V1, V2 on the substrate holders 14 . 16 can be formed.

Same voltage potentials V1, V2 at the opposite to the plasma area 18 arranged substrate holders 14 . 16 cause approximately equal ion currents, so that both at the respective substrate holders 14 . 16 releasably held substrates 4 . 6 far-reaching and exactly the same process conditions are specifically adjustable.

It is further provided that the phases P1, P2 of the first and second power supply 1 . 2 not only among each other, but also in relation to the phase P3 of the third power supply 3 adjustable and can be fixed as needed.

It is sufficient so far, if only one of the three power supplies 1 . 2 . 3 , for example, the power supply 3 , a frequency generator 25 whose signal is in phase with the other two power supplies 1 . 2 is transmitted. For this purpose, for example, the second power supply 2 over a cable 36 with the third power supply 3 coupled. Equally, the first power supply 1 over a cable 38 with the third power supply 3 coupled. Because in this way the first and the second power supply 1 . 2 each separately and separately with the third power supply 3 and their frequency generator 25 can be coupled, the realization of a separate connection line between the first and second power supply is unnecessary 1 . 2 , But it is also possible, instead of the cable 38 between first and third power supply 1 . 3 a phase-true coupling between first and second power supply 1 . 2 for example by means of the cable 38 to realize. It would then be a series circuit of third, second and first power supply 3 . 2 . 1 in front.

The third power supply has an amplifier 24 on that with its input to the frequency generator 25 coupled and with its output with an impedance matching 22 is coupled. About the impedance matching 22 is the amplifier 24 with the excitation coil 20 coupled to an inductive RF excitation in the plasma region 18 to build.

The first power supply 1 is also with its own amplifier 26 and with its own impedance matching 28 as well as with a voltage source 29 Mistake. In this way, an impedance matching for the power supply can also here 1 and a separate amplification of that from the first power supply 1 provided high frequency signal.

The second power supply 2 is virtually identical to the first power supply 1 built up. This also has an amplifier coupled to the first power supply 30 on which the high-frequency signal of the frequency generator 25 receives and amplifies. That from the amplifier 30 amplified signal is via a further impedance matching 32 to the second substrate holder 16 directed. Similar to the first power supply 1 , indicates the second power supply 2 a voltage source 33 on.

The electrical connection between the first power supply and the third power supply and the electrical connection of the second power supply and the third power supply are all power supplies 1 . 2 . 3 inherently phase locked together.

At least two of the three power supplies, typically the first and second power supplies 1 . 2 , are with a phase adjustment 41 . 42 provided by means of which the respective phase of the first and / or second power supply 1 . 2 variable and independent relative to the phase P3 of the third power supply 3 is adjustable. In this way, the phases P1, P2 of first and second power supply can also 1 . 2 be changed and adjusted relative to each other. It is also possible, the relative phase of the first and / or second power supply 1 . 2 relative to the phase P3 of the third power supply 3 adjust. Typically, the phase P3 of the third power supply 3 are always kept constant, while the phases P1 and P2 are variable relative to each other and relative to the phase P3.

The plasma processing apparatus is further provided with a controller 40 provided, which with at least the phase controls 41 . 42 from first and second power supply 1 . 2 data technology is coupled.

In 2 is the dependence of the voltage potentials V1, V2 on the first and second substrate holders 14 . 16 from a variation of the phase P2 of the second power supply 2 shown schematically. The triangular measuring points reflect the voltage potentials V1 at the first substrate holder which respectively set in the given phase 14 , The diamond-shaped measured values reflect the voltage potentials V2 at the second substrate holder 16 ,

Phase P3 of the third power supply 3 and the phase P1 of the first power supply 1 are in the illustration according to 2 constant. The relative phase position DP1P3 is approximately 0 °. It is only the phase P2 of the second power supply 2 changed over a range of 0 to 360 °. It can be seen from the diagram and the course of the resulting voltage potentials V1, V2 that both the first voltage potential V1 and the second voltage potential V2 are approximately sinusoidal or cosine-like with a variation of the phase P2 of the second voltage supply 2 vary. It results in the in 2 shown phase space approximately at 110 ° and 290 ° two intersections of the voltage potentials V1, V2. In these intersections S1, S2 are located on the two substrate holders 14 . 16 largely identical or equal voltage potentials V1, V2 on. The amount of voltage potential is in the selected and in 2 shown example in about -65 volts.

This in 3 The phase diagram shown again shows a variation of the phase P2 over a range of 0 ° to 360 ° with fixed phase P1 and fixed phase P3. However, here is the phase position between the first power supply 1 and the third power supply 3 in comparison to the configuration according to 2 changed. In the present case, the relative phase position DP1P3 is approximately 60 °.

A comparison of the two diagrams according to the 2 and 3 discloses that the points of intersection S1 and S2 migrate, that is to say equal voltage potentials V1, V2 at the first and second substrate holders 14 . 16 now with a relative phase position DP1P2 between the first and second power supply 1 . 2 set at about 150 ° and at 330 °. In addition, it can be seen that the voltage potential of the intersections S1, S2 has increased in size. It is now at about -80 volts.

It should be noted in particular that the over the power supplies 1 . 2 in the substrate holder 14 . 16 fed bias power, a so-called supply power L1, L2 was maintained unchanged. Due to the changed phase relationship between the power supplies 1 . 2 . 3 However, different voltage potentials of the intersections S1, S2 result, which results in selection of one of the intersections in the diagrams according to FIG 2 and 3 different ion currents from the plasma 19 in the direction of the substrates 4 . 6 to adjust.

By setting the phases P1, P2 and P3 such that the first and second substrate holders 14 . 16 identical voltage potentials V1, V2 are present, far-reaching identical coating, or generally, far-reaching identical surface treatment requirements are created. By suitable choice of a relative phase position DP1P3 or DP2P3, that is to say a relative phase position between first and third voltage supply DP1P3 or between second and third voltage supply DP2P3, the voltage potential at the substrate holders can 14 . 16 be adjusted in terms of amount. In particular, it is provided to set a maximum voltage potential Vmax in terms of absolute value, in order to determine the power output of the power supplies 1 . 2 to optimize.

To determine the relative phase positions DP2P3 and DP1P2 of the individual phase-coupled power supplies 1 . 2 . 3 the entire three-dimensional phase space of the phases P1, P2, P3 is to be scanned or completely measured to at least those relative phases between the first and second voltage supply 1 . 2 and a relative phase between the third power supply 3 and one of first and second power supplies 1 . 2 to determine at which the voltage potentials V1 and V2 at the substrate holders 14 . 16 are identical and in terms of amount over the entire phase space considered maximum.

In 4 is the qualitative relationship between the bias voltage on one of the substrate holders 14 . 16 and the resulting mechanical layer stress of a plasma treatment device shown by means of the 10 producible layer on a substrate 4 . 6 shown. With a lower bias voltage, and consequently with an increasing negative bias voltage, an increasing ion current can be directed onto the substrate, which leads to an increased deposition rate of ions to be applied to the substrate. As a result, an outward compressive stress of the coating acting on the substrate edges can be increased.

In 5 Furthermore, the qualitative relationship between the voltage at the power supplies 1 . 2 adjustable bias power and the resulting voltage potential V1, V2 at the respective substrate holders 14 . 16 shown. With rising and into the substrate holder 14 . 16 injected. electrical power can be the voltage potential V1, V2 at the substrate holders 14 . 16 be increased in terms of amount, which leads to an increased ion current and thus to an increased deposition rate.

In 6 a flow diagram of the method for the simultaneous coating of two substrates is shown schematically. In a first step 100 become the first and the second substrate holder 14 . 16 each subjected to a bias power. In a subsequent step 102 will be attached to the substrate holders 14 . 16 adjusting voltage potentials V1, V2 measured in a subsequent step 104 becomes at least one phase P1, P2 of one of the power supplies 1 . 2 changed until the voltage potentials V1, V2 are substantially the same size and in a subsequent step 106 becomes the phase position of one of the power supplies 1 . 2 relative to the phase position of the power supply 3 changed by a predetermined step.

Then the process jumps to the step 104 back so that equal voltage potentials V1, V2 are set. The voltage potentials V1, V2, which adjust identically for each phase position DP1P3 or DP2P3, are typically stored and compared with subsequent or preceding voltage potentials V1, V2 of equal magnitude, respectively, which set in a different phase position DP1P3 or DP2P3. The iteration of the steps 104 and 106 is carried out until the two substrate holders 14 . 16 a maximum voltage potential Vmax forms, which at first and second substrate holder 14 . 16 is the same size.

The representation of the method in the flow chart of 6 only vaguely reflects the actual control algorithm. A variation of the phases P1 and P2 can take place with simultaneous variation of the relative phase of P1 and P3 or also successively and successively. The phase position between P1 and P3 is to be set such that the magnitude of the voltage potential V1, V2 at the same voltage V1 and V2 at any phase position of P1 and P2 is maximum.

In this way, the power yield for the at the substrate holders 14 . 16 applied additional voltage can be maximized.

LIST OF REFERENCE NUMBERS

1

power supply

2

power supply

3

power supply

4

substratum

6

substratum

10

The plasma processing apparatus

12

Plasma processing chamber

14

substrate holder

15

gas distributor

16

substrate holder

17

gas distributor

18

plasma region

19

plasma

20

excitation coil

23

impedance matching

24

amplifier

25

RF generator

26

amplifier

28

impedance matching

29

voltage source

30

amplifier

32

impedance matching

33

voltage source

34

Vacuum pump device

36

connection

38

connection

40

control

41

phase control

42

phase control

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011013467 A1 [0003]
• JP 2007-150012 A [0004]

Claims (11)

Plasma treatment apparatus for surface treatment of substrates, comprising: - a plasma treatment chamber ( 12 ), in which at least one first substrate holder ( 14 ) and a second substrate holder ( 16 ) are arranged, wherein the first substrate holder ( 14 ) in the direction of its surface normal (N) spaced from the second substrate holder ( 16 ) and wherein the first and the second substrate holder ( 14 . 16 ) on opposite sides of a plasma region ( 18 ), - at least one of the plasma region ( 18 ) in the circumferential direction surrounding excitation coil ( 20 ) for excitation of a plasma ( 19 ) in the plasma region ( 18 ), - a first power supply ( 1 ), which with the first substrate holder ( 14 ), - a second power supply ( 2 ), which with the second substrate holder ( 16 ), and with - a third power supply ( 3 ), which with the excitation coil ( 20 ) - at least the phase (P1) of the first power supply ( 1 ) with the phase (P2) of the second power supply ( 2 ) is coupled. Plasma treatment apparatus according to claim 1, wherein the phase (P3) of the third power supply ( 3 ) with at least one of the phases (P1, P2) of first or second voltage supply ( 1 . 2 ) is coupled. Plasma treatment device according to one of the preceding claims, wherein at least one of the three power supplies ( 1 ) an RF generator ( 25 ), which with the other two power supplies ( 2 . 3 ) is coupled. A plasma processing apparatus according to any one of the preceding claims, wherein each of the three power supplies ( 1 . 2 . 3 ) each have an amplifier ( 24 . 26 . 30 ), which are independently controllable. Plasma treatment apparatus according to one of the preceding claims, wherein the phase (P1) of the first power supply ( 1 ) relative to the phase (P2, P3) of at least one of the two remaining power supplies ( 2 . 3 ) is optionally adjustable and fixable. Plasma treatment apparatus according to one of the preceding claims, wherein the phase (P2) of the second voltage supply relative to the phase (P1, P3) of at least one of the two remaining power supplies ( 1 . 3 ) is optionally adjustable and fixable. Plasma treatment apparatus according to one of the preceding claims, further comprising a controller ( 40 ) for the automatic adjustment of a relative phase position (DP1P2) between the first and the second voltage supply ( 1 . 2 ) is formed such that at the same supply power (L1, L2) of the first and second power supply ( 1 . 2 ) equal voltage potentials (V1, V2) at the first and the second substrate holder ( 14 . 16 ) form. Plasma processing apparatus according to claim 7, wherein the controller ( 40 ) for automatically setting a relative phase position (DP1P3, DP2P3) between the third power supply ( 3 ) and one of first and second power supplies ( 1 . 2 ) is designed in such a way that, in terms of magnitude, a maximum voltage potential (Vmax) at one of the first and second substrate holders ( 14 . 16 ). Process for the simultaneous surface treatment of at least two substrates ( 4 . 6 ) by means of a plasma treatment device ( 10 ) according to one of the preceding claims, comprising the step of: - adjusting a relative phase position (DP1P2) between the first and the second voltage supply ( 1 . 2 ) such that at the same supply power (L1, L2) of the first and second power supply ( 1 . 2 ) equal voltage potentials (V1, V2) at the first and the second substrate holder ( 14 . 16 ) train. The method of claim 9, wherein the phase (P1, P2) of one of the first and second power supplies ( 1 . 2 ) with the phase (P3) of the third power supply ( 3 ) and is fixed to the latter and the phase (P2, P1) of the other of the first and second power supply ( 1 . 2 ) is varied until at the first and at the second substrate holder ( 14 . 16 ) form equal voltage potentials (V1, V2). Method according to one of the preceding claims 9 or 10, wherein the phase (P1, P2) of one of the first and second power supply ( 1 . 2 ) relative to the phase (P3) of the third power supply ( 3 ) is varied until a magnitude maximum voltage potential (Vmax) at the first and the second substrate holder ( 14 . 16 ) formed on the first and second substrate holders ( 14 . 16 ) is the same size.

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