EP3289113A1

EP3289113A1 - Method for producing coated substrates

Info

Publication number: EP3289113A1
Application number: EP16714365.0A
Authority: EP
Inventors: Jürgen PISTNER; Harro Hagedorn
Original assignee: Buehler Alzenau GmbH
Current assignee: Buehler Alzenau GmbH
Priority date: 2015-03-31
Filing date: 2016-03-31
Publication date: 2018-03-07
Also published as: WO2016156496A1; US11814718B2; JP6707559B2; TWI624552B; TW201702408A; CN107532290B; CN107532290A; US20180087142A1; JP2018511705A

Abstract

The invention relates to a method for producing substrates having a plasma coated surface made of a dielectric coating material in a vacuum chamber, having an AC-powered plasma device, comprising moving a substrate relative to the plasma device by means of a movement device along a curve, and depositing coating material on a surface of the substrate in a coating region along a trajectory lying on the surface of the substrate using the plasma device. Also provided is: a) the determining of actual values of a layer thickness of deposited coating material on at least parts of the trajectory in the movement direction of the substrate; b) the comparing of the actual values with target values of the layer thickness on the at least parts of the trajectory; c) the determining of parameters of the plasma device to change the amount of coating material deposited per time unit i accordance with the position of the substrate, in such a way that the actual values of the layer thickness of deposited coating material deviate by less than a predetermined difference from the target values; d) the setting of parameters of the plasma device to change the amount of coating material deposited per time unit according to point c); and e) depositing coating material by means of the plasma device, using the parameters set in point d). The invention further relates to a device for producing substrates (10, 100) having a plasma-coated surface made of a dielectric coating material in a vacuum chamber, having an AC-powered plasma device (31, 32, 150, 180), comprising a movement device for moving a substrate (10, 100) relative to the plasma device (31, 32, 150, 180) along a curve, wherein by means of the plasma device (31, 32, 150, 180) coating material is deposited on a surface (11, 101) of the substrate (10, 100) in a coating region along a trajectory lying on the surface of the substrate (12, 105), comprising a control module (140) which is designed and configured to carry out the method.

Description

description

PROCESS FOR PRODUCING COATED SUBSTRATES

The invention relates to a method for the production of substrates with a plasma-coated surface and to an apparatus for carrying out the method according to the preambles of the independent claims.

For the production of substrates with a plasma-coated dielectric surface, various methods in the field of physical and chemical deposition techniques are known in which coating material is deposited from a plasma on a surface of the substrate, the deposition techniques depending on the chosen material system and to achieve the desired Properties of the coated surface can be used.

As a sputtering, the particle bombardment is subsequently induced

Activation of atoms and molecules from a solid surface, in which a plasma is ignited in a vacuum by the action of an electric field, from which ions are accelerated onto a target, which ions strike atoms from the target, which then on the walls the vacuum chamber and precipitate on a substrate spaced from the target. In this case, there is a residual gas pressure, usually predominantly an inert gas such as argon, which shows no disturbing influences on the layer forming on the substrate. Magnetron arrangements are often used to increase the ion current density. A heating of the material source is not necessary, but the target is usually cooled in the implementation of the process.

For the deposition of compounds such as nitrides, carbides or oxides or the like, the sputtering gas (residual gas) may additionally be mixed with reactive gases. For the production of insulating layers, such as Si0 ₂ , Al ₂ 0 ₃ and the like, processes have been developed in which by means of two magnetron sputtering cathodes from a

AC power source are fed, two targets are used alternately. The polarities of the target potentials usually change in the KHz range, i. each electrode is alternately cathode and anode. This leads to a defined charge transport between cathode and anode without inhibiting influence of an oxide layer on the

Target surfaces, in contrast to the disturbing effect of the so-called "disappearing anode" in a reactive DC magnetron sputtering process. For efficient operation, work is usually carried out in the so-called transition mode, since otherwise the oxide formation at the target surface is faster than the removal rate.

In order to generate a plasma or ion beam, excited sourceless plasma sources are also known in a frequency range between 1 MHz and 100 MHz, which may be lattice-free or have a plasma space enclosed by a grating, whereby the plasma is also normally subjected to a magnetic field in these plasma sources.

From DE 694 210 33 T2, for example, an inductive plasma source operated in the radio frequency range (RF) is known in which, with a reduced number of system components, the plasma density is increased by permanent magnets arranged outside a vacuum chamber. DE 100 084 82 A1 discloses a plasma source operated in a high-frequency (HF) range with a magnetic field coil arrangement and a unit for extracting a plasma jet, superimposing a transverse magnetic field on an excitation electrode, and magnetic field coils around a plasma volume for generating a transverse magnetic field are arranged. In this case, it is possible to choose between capacitive and inductive plasma excitation, wherein the ion energy can be set in a range from 10 eV to about 1000 eV.

A capacitively coupled plasma source is known from EP 0 349 556 B1, according to which a plasma jet can be extracted, for example, for the removal and structuring of solid surfaces, for the production of surface dopants by particle bombardment or for the production of surface layers.

From WO 2005/008717 a capacitively excited RF plasma source for generating a shaped by magnetic fields plasma jet is known, in which by a homogeneous

Magnetic field allows a local increase in the plasma density and thus operation of the source at relatively low plasma pressures, wherein the generation of the magnetic field

For example, permanent magnets are provided.

Furthermore, devices are known which have a combination of a sputtering device with a targetless plasma source, for example one of the plasma sources described above.

From EP 0 516 436 B1 is a combination of a magnetron sputtering device with a secondary plasma device for the reactive deposition of a material on a substrate. The sputtering device and the secondary plasma device each form sputtering and Activation zones that are atmospherically and physically adjacent. By the

Matching the sputtering and activation zones, the plasmas of both zones are mixed into a single continuous plasma.

EP 0 716 160 B1 discloses a coating device with a sputtering device and with a device for generating a plasma of low-energy ions. The sputtering and plasma devices can be selectively operated so that a

Composite layer is formed, which has at least several layers. The

Composition of each layer may be selected from at least one of the following materials: a first metal, a second metal, an oxide of the first metal, an oxide of the second metal, mixtures of the first and second metals, and oxides of mixtures of the first and second metals.

From EP 1 592 821 A2 a method for the production of very low-loss optical layers on a movable substrate in a vacuum chamber with a residual gas by means of a sputtering device is known. In this case, such a layer is at least two

Constituent formed, wherein at least a first constituent a sputtering material of

Sputtering device and at least a second constituent is a reactive component of the residual gas. It is envisaged that a reactive deposition of a layer with a predetermined stoichiometric deficit of the reactive constituent in a spatial region of the sputtering device on the substrate, a movement of the substrate with the deposited layer in a spatial region of a plasma source at a predetermined distance from the sputtering device is arranged in the vacuum chamber and a precise modification of the structure and / or stoichiometry of the layer by subsequent plasma action of the plasma source to reduce an optical loss of the layer takes place. A desired layer thickness of the deposited layer can via a

Be set coating time, for example, in situ using an optical layer thickness measurement by an optical monitor.

In many applications of coating processes, a given uniformity of the deposited layers with regard to their optical, mechanical and chemical properties as well as a high reproducibility of a retracted layer are

Coating process and thus appropriate control methods of importance.

When coating moving substrates are used to control

Layer thickness deviations perpendicular to the direction of movement often Aperturblenden used, as described for example in the publication vacuum coating (publisher Gerhard Kienel, Springer Verlag 1995). From DE 27 00 979 A a method is known to regulate a vapor deposition rate and / or the composition of the material to be vaporized during a vacuum evaporation process in which a portion of the material to be evaporated flows through a measuring zone in which the material to be evaporated is exposed to radiation , wherein the type of radiation is chosen so that the electrons of at least a part of the measuring zone

flowing through atoms of the material to be evaporated are raised to a higher energy level, and that the resulting in the return transition to the low energy state photons are registered as a measure of the Aufdampfrate or as an information signal for the composition of the material to be evaporated.

In order to ensure a stable sputtering process at a desired operating point, current, voltage and power controls can be used with a constant gas inlet, as for example in EP 0 795 623 A1. Furthermore, it is known from DD 271 827 13 to carry out the regulation of the gas inlet at a constant power supply with the aid of a plasma emission monitor. Furthermore, a reactive sputtering method from WO 01/73151 A1 is known, wherein the oxygen partial pressure in the sputtering gas at

Sputtering of the oxide is controlled by means of a lambda probe.

From US 5,225,057 a coating method for forming a thin film on a substrate with a cylindrical sputtering system with a sputtering zone for depositing a metallic layer and a separate from the sputtering zone plasma zone of a plasma source for subsequent oxidation of the metallic layer is known. Due to a non-equidistant movement of the substrate relative to the sputtering source occurs with this

Sputtering system produced a parabolic layer thickness distribution, which is called chordal effect. To compensate for this layer thickness distribution and for the production of uniform layers is proposed, the sputtering in the

Deposition of the metallic layer according to a predetermined profile in

Dependence on the position of the substrate relative to the sputtering source to modulate. A regulation of the sputtering system or the layer thickness distribution is not mentioned.

From EP 1 198 607 B1 a further method for the production of workpieces is known with which the chordal effect is to be compensated. The workpieces for reactive vacuum treatment are moved through a treatment atmosphere in a treatment area. The treatment atmosphere is controlled in the treatment area, wherein the treatment atmosphere currently prevailing in the treatment area is detected with a sensor and the treatment atmosphere is modulated with a predetermined profile as a function of the workpiece position. Modulating takes place by changing the nominal value of the Control or in a frequency range which is above the upper limit frequency of the closed loop of the scheme. With this procedure is intended for in the

Treatment atmosphere moving workpieces regardless of their trajectory and - alignment targeted a desired layer thickness distribution can be realized. It is also proposed that in one modulation unit one, preferably two or more

Modulation waveforms pre-stored and selectively activated by means of a selection unit for the respective machining process. With the pre-deposited, different modulation curve shapes different substrate treatments can be considered at the same plant.

Also in this known method, a control of the layer thickness distribution is not proposed or discussed, but set the layer thickness distribution controlled.

A method for producing magnetron sputter-coated substrates is also known from EP 1 552 544 B1, in which a magnetron magnetic field pattern along the sputtering surface is cyclically moved on a magnetron source with a sputtering surface, the substrate is moved away from and above the sputtering surface, being with the cyclic

Movement of the magnetic field pattern phase locked, the amount of material deposited per unit time on the substrate changes cyclically. In particular, it is proposed that one measures the material distribution currently stored on the substrate as a measured controlled variable, compares it with a desired distribution and, in accordance with the comparison result, as

Control difference, the course of the phase-locked cyclic change as a manipulated variable in a control loop for the mentioned distribution. In this method, it is assumed that, in principle, in the case of a two-dimensional or three-dimensional cyclic movement of the magnetron magnetic field pattern, that component of motion which is perpendicular to the direction of movement of the substrate is decisive. With the known method is to be achieved in particular that one can do without aperture apertures.

The known prior art merely aims to compensate for layer thickness distributions which deviate from desired distributions due to the chordal effect or mechanical inaccuracies of the installations. Deviations from one

predetermined layer thickness distribution due to the individual plasma conditions of the deposition process as well as the varying thickness and varying dielectric properties of the deposited dielectric layer itself are not taken into account.

Document DE 10 2013 101 269 A1 describes how, in the case of magnetron sputtering, a measurement of layer properties can be carried out, with transmission, reflection and / or sheet resistance measurements on certain traces on the substrate. The corresponding device comprises so-called gas channel segments, each with its own gas inlet for the separate coating of areas of the substrates. In paragraph [0022] of this document, the following is carried out: In this case, the user can carry out an analysis of the layer at any location where influence on the layer properties can be made by changing the process gas quantity and composition. It is meant a location of the arrangement described in the document and not a location on the substrate.

The document DE 102 34 855 A1 describes a device for setting a predetermined layer thickness distribution by means of a coating source, in which a passage opening for the vapor between the coating source and the substrates is delimited by at least two partial diaphragms movable to the transport direction of the substrate. Due to the design, no layer thickness distribution in the direction of movement of a substrate to be coated can be set with this device. It means

Correspondingly, in paragraph [010] of this document: In this way the achievable layer thickness distribution can be adjusted very finely with high local resolution transversely to the direction of movement of the substrates.

Applicant's investigations into the layer thickness distribution in dielectric layers deposited by means of an alternating current plasma device have shown deviations in the direction of movement of the substrate from a layer thickness distribution to be expected with constant cathode power, in particular a layer thickness edge drop which is not due to a chordal effect or mechanical inaccuracies of the system

but due to the specific plasma conditions of the

Deposition process, such as the electric field of the plasma boundary layer, are conditional. It has also been found that the observed layer thickness distribution depends, inter alia, on substrate support structures, such as the size and position of openings in which the substrates are housed, the material of the substrate and the substrate support, the speed at which the substrates are moved.

The object of the present invention is to provide a method and a device, with which coating material on a surface of a substrate with a low

Deviation from a predetermined layer thickness distribution in the direction of movement of the substrate can be deposited, and also deviations that can be considered and compensated by the individual plasma conditions of the deposition process. The object is achieved with the features of the independent claims.

The inventive method for producing substrates with a plasma-coated surface of a dielectric coating material in one

Vacuum chamber, which has a powered with an alternating current plasma device, with

Moving a substrate relative to the plasma device by means of a movement device along a curve,

Depositing coating material on a surface of the substrate in one

Coating area along a lying on the surface of the substrate trajectory means of the plasma device, characterized by a) determining actual values of a layer thickness of deposited

Coating material on at least parts of the trajectory in the direction of movement of the substrate b) Comparison of the actual values with target values of the layer thickness on the at least parts of the trajectory c) Determining parameters of the plasma device for changing the amount of coating material deposited per unit time as a function of the position such that the actual values of the layer thickness of deposited coating material deviate less than a predetermined difference from the target values, and d) setting parameters of the plasma device for changing the amount of coating material deposited per unit time according to item c) e) deposition of coating material by means of the plasma device with the parameters set in point d).

The method involves moving a substrate relative to the plasma device by means of a movement device along a curve. By means of the plasma device is

Coating material deposited on a surface of the substrate in a coating area along a lying on the surface of the substrate trajectory. Preferably is here understood as trajectory the path or the path of movement of the coating area when moving the substrate relative to the plasma device.

The coating area is determined by the coating window of the

Plasma device. The coating window here is a surface which is at a distance from the plasma device and on which coating material is deposited when the substrate is not moved relative to the plasma device.

After a certain coating time or with a turntable device of a certain number of coating passes of the substrate, the actual values of the layer thickness of deposited coating material deviate less than a predefined difference from the desired values of the layer thickness. Additional coating material is thus deposited as a function of the difference between actual values of the layer thickness and the desired values.

Preferably, desired values are selected which correspond to a uniform layer thickness. However, it is understood that even gradient layer distributions with the

can be prepared according to the invention.

The plasma device can have an aperture diaphragm which is known per se, in order additionally to achieve a uniform layer thickness distribution perpendicular to the direction of movement of the substrate. With such an aperture diaphragm, however, it is not possible to correct the layer thickness distribution in the direction of movement of the substrate.

From the document "The origins of self-bias on dielectric substrate in RF plasma processing, surface and coating technology" 200 (2006) 3670-3674 (Y. Yin et al.) It is known that in dielectric layers of the layer-adjacent self-bias sensitive of the

Plasma conditions of the deposition process is dependent. For example, the self-bias in a dielectric substrate is affected by the substrate thickness as well as the accumulation of surface charges, which in turn are determined by the plasma conditions. The self-biasing process regenerates the growing layer and thus influences the layer thickness distribution and other properties of the deposited layer.

With the method according to the invention it is also possible, in particular, deviations of the layer thickness from a predetermined layer thickness distribution on the trajectory in

Moving direction of the substrate, which are due to the changing during the movement of the substrate individual plasma conditions of the deposition process and by the varying thickness and varying dielectric properties of the deposited dielectric layer itself. This is possible because additional Coating material is deposited as a function of the difference between actual values of the layer thickness and the target values, regardless of the cause of the difference.

According to the invention, the actual values of the layer thickness on at least parts of a trajectory lying on the surface of the substrate are constantly approximately equal to the desired values of the layer thickness. For this purpose, according to the invention, the actual values are compared with target values of the layer thickness and parameters of the plasma device are determined in order to change the amount of coating material (coating rate) deposited per unit time as a function of the position of the substrate. The position of the substrate preferably corresponds to a position of the coating window of the plasma device relative to

Substrate surface.

In particular, the invention contemplates that upon operation of the plasma device with plasma excitation with RF (13.56 MHz) and MF (40KHz), a self-bias is imposed on the substrate based on the geometry and material of the environment of the substrate as well as the electrical charge the environment and the substrate is dependent.

The Applicant's investigations have shown that with moving substrates and constant power of a sputtering cathode, a layer thickness edge drop at

Coating material of elements such as Si and Al, Mg and their oxides and nitrides is significantly stronger than Nb, Hf and Ta and their oxides and nitrides, in which the layer thickness edge drop was below the detection limit.

The Applicant's investigations have further shown that with moving substrates and constant power of a sputtering cathode, a layer thickness edge decrease is greater with RF plasma excitation than with MF plasma excitation, for example with RF for SiO 2 layers

Substrates with a diameter of 200mm a layer thickness edge drop of 2% - in contrast to a layer thickness edge drop of 0.6% at MF.

Preferably, the plasma device is operated with RF or MF or the deposition is carried out by means of a stimulated with RF or MF plasma. The invention makes it possible to substantially reduce the layer thickness edge drop in flat substrates, for example, in sputtering of SiO 2 with RF plasma excitation in a substrate with a

Diameter of 200mm from 2% to 0.5%.

The invention thus makes it possible in a simple manner to take into account the influence of geometry and material of the substrate environment on the deposition process. In particular, the mechanical and electrical structure of the plasma device as well as the Vacuum chamber easier and cheaper, since you no longer have to pay attention in the design of the plasma device and / or vacuum device, which set electrical potentials in the deposition process, but by determining and setting parameters of the plasma source according to point c) and d) per unit time Deposited amount of coating material advantageously changes the influence of

Geometry and material of the substrate environment to compensate for the deposition process.

In contrast to the method known from EP 1 198 607 B1, according to which the

Layer thickness is controlled, in the present invention, if the determined actual values of the layer thickness differ not less than the predetermined difference from the target values, the plasma device is operated such that the deposited amount of

Coating material is changed until the actual values of the layer thickness deviate less than a predetermined difference from the target values.

An embodiment of the method according to the invention is characterized in that parameters of the power supply and / or parameters of the gas supply of

Plasma device and / or parameters of the plasma emission of the plasma device according to point d) can be adjusted. In this case, the plasma device can be controlled or regulated to the deposition rate and / or other layer properties, such as

Layer density, adhesion, internal stress, surface morphology or microstructure.

Another embodiment of the method is characterized by determining the actual values by measuring in situ in the vacuum chamber according to point a). Basically, the determination of the actual values by measuring in-situ in the vacuum chamber has the advantage that a removal of the substrate from the vacuum chamber and the associated expense can be avoided and thus increases the process reliability and the process time can be reduced.

The determination of the actual values in situ can take place, for example, by means of an optical monitoring system.

After the actual values have been measured, the comparison is made in accordance with point b). If the actual values of the layer thickness of deposited coating material deviate less than a predetermined difference from the desired values, the substrate can be further processed, in particular removed from the vacuum chamber. Otherwise, point c) and point d) and a further deposition of coating material take place. Another embodiment of the method is characterized by removing the

Substrate from the vacuum chamber before point a) and determining the actual values by measuring ex situ outside the vacuum chamber according to point a), whereby a greater accuracy in determining the actual values can be achieved. The measurement of the actual values preferably takes place spectrally-ellipsometrically with a spectral ellipsometer. After the actual values have been measured, the comparison is made in accordance with point b). If the actual values of the layer thickness of deposited

Coating less than a predetermined difference from the target values, the substrate can be further treated, optionally in or outside the

Vacuum chamber. Otherwise, point c) and point d) and further deposition of

Coating material on the re-introduced into the vacuum chamber substrate.

A further embodiment of the method is characterized in that the parameters of the power supply are an electrical current, an electrical voltage, an electrical power and / or a plasma impedance. Thus, according to the invention, an electrical current, an electrical voltage, a plasma impedance and / or an electric power are changed or modulated as a function of the position of the substrate.

A further embodiment of the method is characterized in that the parameters of the gas supply to the plasma device are a working gas flow and / or a reactive gas flow into the plasma device or into a space between

Plasma device and substrate acts.

Another embodiment of the method is characterized in that the

Plasma device is designed as a sputtering source with one or more sputtering cathodes (sputtering targets) or has such a sputtering source and the deposition takes place as sputtering. The sputter source can be controlled. The sputtering source can be operated in particular, as known per se, in the metallic or in the reactive mode or by a commutation of the reactive discharge between the metallic mode and the reactive mode. The sputter source can also be actively regulated.

Preferably, an electric power of the sputtering cathode or the sputtering cathodes, and thus the deposition rate, is changed or modulated depending on the position of the substrate. Preferably, the electrical power is modulated according to a triangular profile, a rectangular profile, a sine profile, a Sin 2 profile or a pulse profile. It is understood that these profiles are also used in other plasma devices as sputtering sources for

Power modulation can be used. Another embodiment of the method is characterized in that the deposition takes place by means of a plasma device which is designed as a targetless plasma source or has such a plasma source.

Another embodiment of the method is characterized by deposition by means of a sputtering source and additional plasma treatment of the substrate, as is known per se from EP 1 592 821 A2. The sputtering source can also be operated in the metallic mode or in the reactive mode. The use of the method is particularly advantageous for deposition by means of a sputtering source and an additional plasma treatment of the substrate, since the additional plasma treatment can greatly influence the plasma conditions, in particular the electrical potentials during the deposition process.

Another embodiment of the method is characterized by moving the substrate along a linear curve, such as in an in-line system. Alternatively or additionally, it is also possible to move the substrate along a nonlinear curve,

be provided in particular a trained as a circle or arc curve. This can be done for example by means of a turntable or cylinder system.

Another embodiment of the method is characterized by moving the substrate along a curve that is equidistant from the plasma device.

Another embodiment of the method is characterized by moving the substrate along a curve which is non-equidistant with respect to the plasma device,

is formed in particular concave or convex and determining parameters of

Plasma device for changing the amount deposited per unit time of

Coating material according to point c), until the actual values, for example, also excluding the chordal effect, deviate less than a predetermined difference from the desired values.

Another embodiment of the method is characterized by selecting the

Coating material from a group comprising at least one of the elements silicon,

Aluminum, magnesium, hafnium, zirconium, niobium, tantalum, titanium, scandium and / or their oxides or nitrides.

Another embodiment of the method is characterized by the use of a disc-shaped substrate.

Another embodiment of the method is characterized by using a disc-shaped substrate having a largest linear dimension or a largest one Diameter smaller than a coating window of the plasma device. When

Coating window is here referred to a spaced-apart from the plasma device surface on the at not relatively moving relative to the plasma device substrate

Coating material is deposited.

In the case where a plurality of similar substrates are moved at equivalent positions by the moving means and depositing coating material on a surface of the substrate in a coating area along one of the surfaces

It should be understood that the parameters determined not only for the deposition of

Coating material can be used on a substrate for which the actual values of a layer thickness have been determined, but that also the deposition of

Coating material on some or all of the other substrates can be done with the set parameters of the plasma device. In one embodiment of the invention, for example, substrates of the same diameter, the same substrate thickness and the same material for the production of substrates having layers with the same

Layer thickness profiles are coated with the same parameters of the plasma device when they are located at equivalent positions of the moving device. The set parameters can then be saved as a process profile.

According to a further aspect of the invention, a method for the production of

provided with a plasma-coated surface of a dielectric coating material substrates provided in a vacuum chamber by a coating system, wherein the coating plant has a powered with an alternating current plasma device.

It is planned

Providing at least one selectable process profile by means of a memory module of a control module,

Selecting one of the provided process profiles by means of an input unit of the control module, wherein the selected process profile is assigned to the control module as an operating configuration,

Controlling the moving means, wherein the plasma source or the substrate by means of the controlled moving means based on the as operating configuration associated stored process profile is moved along a contour of the surface relative to the surface of the substrate,

Acquiring measuring parameters at at least one measuring point of the contour on the surface of the substrate by means of a measuring sensor of the system,

Quantifying the material characteristic parameters determined by the sensor by the control module based on predefined surface classifications, wherein predefined material characteristic parameter ranges are each associated with a surface classification and wherein the corresponding quantification of the corresponding surface classification is triggered by triggering material characteristic parameter ranges based on the

Material characteristics parameters,

Generating a plasma source control signal by a computing module of

Control module based on the surface classification and a

Plasma source parameter profile of the process profile that characterizes the correlation between the surface classification and the plasma source control signal,

Controlling the plasma source by means of the plasma source control signal according to the surface classification and plasma source parameter profile of the process profile for depositing coating material on a surface of the substrate in a coating area along a lying on the surface of the substrate trajectory means of the plasma device.

A device according to the invention for the production of substrates with a plasma-coated surface of a dielectric coating material in one

A vacuum chamber having an alternating current operated plasma device, comprising moving means for moving a substrate relative to the plasma device along a curve, wherein by means of the plasma means depositing coating material on a surface of the substrate in a coating area along one on the surface of the substrate lying trajectory is characterized by a control module that is designed and set up for a1) determining actual values of a layer thickness of deposited

Coating material on at least parts of the trajectory in the direction of movement of the substrate by means of a layer thickness measuring device, b1) comparing the actual values with target values of the layer thickness made available by a presetting device on the at least parts of the trajectory by means of a comparison device, c1) determining parameters of the plasma device by means of a calculation module of the control module for changing the amount of .times

Coating material depending on the position of the substrate such that the actual values of the layer thickness of deposited coating material are less than a predetermined difference from the target values, and d1) setting parameters of the plasma device by means of a setting module of the control module for changing the deposited per unit time Quantity of coating material according to point c1) e1) deposition of coating material by means of the plasma device with the parameters set in point d).

The device has the corresponding advantages of the method according to the invention.

In the following, the invention will be described with reference to drawings

Embodiments described in more detail, from which also independent of the

Summary in the claims further features, details and advantages of the invention.

In a schematic representation:

Figure 1 is a sketch of a preferred apparatus for sputter coating of substrates;

FIG. 2 shows a block diagram of a device according to the invention for carrying out the method according to the invention;

Figure 3 layer thickness distributions on a substrate without and with compensation of a

Coating thickness edge drop;

FIG. 4 shows position-dependent power modulation for compensating the

Schichtdickenrandabfalls in Figure 3. Identical elements are designated in the figures with the same reference symbols.

Figure 1 shows a schematic representation of a preferred device 1 for

Sputter coating of substrates 10 in a sputter-down configuration with the possibility of additional plasma treatment of the substrates 10. The device 1 is arranged in a vacuum chamber, not shown. The device 1 comprises a process module 25 with an alternating-current-operated plasma device, which is designed as a sputtering source 31, and with a plasma source 32. The device 1 further comprises an optional

Cover 26 and a moving device, which is designed as arranged under the cover 26 turntable 20 for moving the substrate 10 relative to the

Plasma device 31 along a circular arc. The turntable device 20 can receive a plurality of substrates which are moved about the axis Z. The substrates 10 may, for example, be accommodated in suitable openings of an annular substrate turntable 21. The substrate turntable 21 can be loaded or unloaded via a lock 28 with substrates. By means of a heating device 27, the substrates can be heated, wherein the heating device 27 is preferably designed as a radiant heater with quartz heaters. Thus, the substrates can be heated to several 100 °, for example to 250 ° C.

The movement device 20 can preferably be operated at an adjustable speed of the turntable 21 between 1 and 500 rpm. Instead of a planar one

Movement device can also be a known per se drum-shaped device for moving the or the substrates are used. In this case, the sputtering source and the plasma source are associated with a peripheral surface area of the drum.

Furthermore, a movement device for moving a substrate along a linear curve can also be provided.

The sputtering source 31 is preferably a magnetron source, more preferably a

Magnetron source system with two adjacent magnetron arrangements. The (not shown) power supply of the sputtering source 31 is preferably a medium frequency (MF) - or radio frequency (RF) - or a DC pulse - supply unit, via a

Matching network are coupled to the sputtering cathodes. preferred

Voltage ranges of the sputtering cathodes used are 400-800 V. Preferably, a 13.56 MHz RF sputtering source and / or a 40KHz MF source is employed. Preferred is a power output to the sputtering cathodes in the range between 500W and 20kW. The Power scales with the area of the cathode up to a maximum value of about

20W / cm2.

The sputtering source 31 can be operated in a known metallic mode, a reactive mode or in transition mode. Preferred sputtering materials are metals and their oxides and nitrides such as Al, Mg, Zr, Hf, Ta as well as semiconductors such as Si and their oxides and nitrides.

The plasma source 32 generates a plasma containing excited ions and radicals of a residual gas. The residual gas includes an inert gas such as argon and optionally one or more reactive ingredients such as oxygen or nitrogen. The plasma modifies the layers of coating material deposited on the substrate by the sputtering source 31. For example, by means of the plasma source 32, an oxidation or nitridation. The plasma source 31 may be, for example, a DC, RF, or DC pulse or DC + RF plasma source device. Preferably, the ion energy of the plasma produced by means of the plasma source 32 is adjustable, preferably in a range between 10 EV 200 EV or even 400 EV. Preferably, an ECWR plasma source is used, in which the energy of the plasma particles can be set largely independently of the plasma density in the plasma source.

In further embodiments, further sputter sources and / or plasma sources are provided in the vacuum chamber.

At a suitable position relative to the substrate turntable 21 is one in Figure 1

not shown optical measuring device arranged for optical monitoring, by means of which the optical properties of the deposited coating material can be determined. As is known, transmission and / or reflection are preferred

intermittently measured by at least one of the substrates for determining optical properties. Preferably, the optical measuring device is a layer thickness measuring device, particularly preferably a spectrophotometer, ellipsometer or a spectral ellipsometer, with which actual values of the layer thickness in situ can be determined selectively or along a trajectory.

In the coating, the substrate 10 is removed from the turntable device 20 under the

Sputtering source 31 moves, wherein coating material is deposited in a coating area along a lying on the surface 1 1 trajectory. In the embodiment shown in FIG. 1, the coating window has a larger area than the substrate. It is understood that the invention can also be used with substrates in which the substrate has the same or larger area than the coating window. After deposition of coating material by means of the sputtering source 31, the substrate is moved on in a circular fashion by the turntable device 20 and reaches the plasma source 32 at a certain point in time, wherein an additional plasma treatment can take place.

For example, a further oxidation of the deposited coating material can take place, as described in detail in the Applicant's EP 1 198 607 B1. Subsequently, a further deposition of coating material by means of the sputtering source 31 can take place.

In principle, it is also conceivable that a deposition of coating material takes place through the plasma source 32.

FIG. 2 shows a device for carrying out the method according to the invention with a plasma device 150, a movement device 160 and a control module 140.

The plasma device 150 and the movement device 160 can, as in the

Embodiment of Figure 1 may be formed. Of course, other embodiments are also possible. The control module 140 includes a computing module 141 and a

Adjustment module 142. The device further comprises a layer thickness measuring device 110, a presetting device 120 and a comparison device 130.

In Figure 2, one for determining the actual values by measuring ex situ is outside the

Vacuum chamber configured and designed device shown, wherein a determination of actual values of a layer thickness of deposited coating material on at least parts of a trajectory 105 in a removed from the vacuum chamber substrate 100 takes place. Unlike in FIG. 2, in a turntable device, as in FIG. 1, the trajectory is usually curved in accordance with the orbital motion of the substrate.

The determined measured values are supplied to the comparison device 130 and compared with the desired values stored in the default device 120 and made available to the comparison device 130. The comparing means 130 supplies a comparison result between the actual values and the target values to the control module 140.

A position sensor 155 may detect a position of a substrate. By way of example, an edge of a substrate can also be detected, with the knowledge of a speed of the substrate, in particular of the rotational speed of a turntable, allowing precise determination of the position of the substrate to be carried out by the control module 140. The calculation module 141 of the control module 140 determines parameters of the plasma device 150 in order to change the amount of coating material deposited per unit time such that the actual values of the layer thickness of deposited coating material deviate less than a predetermined difference from the desired values. This can be done by assigning the actual values and the desired values to specific locations on the trajectory 105. In an installation, as in the exemplary embodiment illustrated in FIG. 1, the position at which the actual values of the layer thickness can be measured, on which curved trajectory - unlike in FIG. 2 - is then determined by a rotation angle which corresponds to the rotation of the Substrate carrier plate 21 about the axis Z corresponds, while the substrate is performed under the sputtering source 31.

The calculation module 141 of the control module 140 determines parameters of the plasma device 150 in order to change the amount of coating material deposited per unit time depending on the position of the substrate such that the actual values of the layer thickness of the deposited coating material are less than the predetermined difference from the target value. Values differ, it being understood that a certain coating time or at a

Turntable device is associated with a certain number of coating passes of the substrate. The control module 140 then adjusts the parameters of the plasma device by means of the adjustment module 142 to the values which are determined by means of the calculation module 141.

In the simplest case, if actual values and target values deviate more than the predetermined difference, the substrate is brought back into the vacuum chamber and moved with the movement device 160, deposition of coating material taking place by means of the plasma device 150 with the set parameters. Preferably, the power supplied by a power supply is modulated by the control device 140 as a function of the position of the substrate, wherein it is preferred in a sputtering device if the sputtering power is modulated according to a triangular profile, a rectangular profile, a sinusoidal profile, a sin 2 profile or a pulse profile.

In the event that a plurality of similar substrates are moved at equivalent positions by the moving means 160, it will be understood that the detected ones

Not only can parameters be used for depositing coating material on the substrate 100 for which the actual values of a layer thickness have been determined, but also depositing coating material on some or all or all of the remaining substrates with the parameters set Plasma device can be done. For example, in the embodiment of the invention according to FIG. 1, substrates can be identical Diameter, same substrate thickness and the same material with the same parameters of the plasma device are coated.

In basically the same way, the process can be carried out if the determination of the actual values of the deposited coating material takes place in situ in the vacuum chamber, wherein, of course, the removal of the substrate when determining the actual values is omitted.

To further increase productivity, provision is made of at least one

selectable process profile by means of a memory module of the control module 140.

Furthermore, one of the provided process profiles is selected by means of a

Input unit of the control module 140, wherein the selected process profile is assigned to the control module 140 as an operating configuration. Then, the movement means 160 is moved in accordance with the associated stored process profile along a contour 105 of the surface relative to the surface 101 of the substrate 100.

Furthermore, measuring parameters are acquired at at least one measuring point of the contour 105 on the surface 101 of the substrate 100 by means of a measuring sensor of the system.

Furthermore, the material characteristic parameters determined by the sensor are quantified by the control module 140 on the basis of predefined ones

Surface classifications, wherein predefined material characteristic parameter areas are each assigned to a surface classification and wherein the corresponding

Quantification of the corresponding surface classification by triggering

Material characteristic parameter ranges based on the material characteristic parameters.

Furthermore, a plasma source control signal is generated by a computing module of the control module 140 based on the surface classification and a

Plasma source parameter profile of the process profile, which characterizes the correlation between the surface classification and the plasma source control signal.

Furthermore, the plasma source is controlled by means of the plasma source control signal

according to the surface classification and plasma source parameter profile of

Process profile for depositing coating material on a surface of the substrate in a coating area along a lying on the surface of the substrate

Trajectory by means of the plasma device. FIG. 3 shows a further embodiment of the invention, wherein in a sputter-up configuration a dual magnetron 180 is shown, which is arranged underneath a substrate plate 190 of a movement device which is not otherwise shown in any more detail. From an inert gas container 220, for example argon, and a reactive gas container 230, for example oxygen, an inert gas or a reactive gas can be introduced into the interior of the vacuum chamber 170 via gas inlets 210 and 21 1. An inert gas and reactive gas flow may depend on measured values of a sensor 200, for example a

Lambda probe whose signal is evaluated by a sensor evaluation device 202 and a control or regulating device 240 is supplied, are set. It is understood that the vacuum chamber 170 also has pumping means, which are not shown for simplicity. The magnetron 180 is connected to a power supply 170 via an unrepresented matching network.

By means of a position sensor 250, the position of a at a bottom of the

Substrate support plate 190 attached, but not shown, substrate are determined. For example, the position sensor 250 may detect a peripheral edge of a substrate. If the rotational speed of the turntable is known, an accurate position determination of the substrate by the control module 140 can be carried out on this basis.

The embodiment further includes, but not shown in Figure 3, components for determining the actual values and target values of deposited coating material on the substrate or substrates and a comparison device for comparing the actual values with the desired values on at least parts of the Surface of the substrate lying trajectory.

In FIG. 3, the power supplied by the generator 170 to the dual magnetron 180 is preferably modulated by the control device 140 as a function of the position of the substrate. In this case, the magnetron sputtering source 180 can be controlled via the control device 240 or regulated using measured values of the sensor 200.

FIG. 4 shows plots of measurement results of layer thickness distributions of deposited coating material on circular planar substrates by means of a device as shown in FIG. 1, the ordinate indicating the layer thickness with respect to an arbitrary value 100 and the abscissa indicating the position on a trajectory on the surface is indicated by a diameter of the circular substrate. Of the

Zero point corresponds to the center of the circular substrate. The areas to the left and right of the zero point correspond to positions on a trajectory in the direction of movement of the substrate. The layer thickness measurements were ex situ. The curves show results of layer thickness measurement of silicon dioxide deposited by controlled RF sputtering. The curve labeled 400 corresponds to a deposition with a constant sputtering power of 10,000W. The curve 400 shows a maximum of the layer thickness in the region of the center of the substrate for the deposited layer with a decrease to the edges left and right by more than 2%.

The curve 401 shows measured values for SiO 2 deposited according to the method according to the invention, wherein a modulation of the sputtering power, which is dependent on the position of the substrate below the center of the sputtering source, was used. It was the of the

Power supply of the sputter source available electric power modulated according to a triangular profile, the power was increased by a maximum of 5% compared to the constant value at which the curve 400 was sputtered increased. The

Modulation of the sputtering power according to the invention resulted in an increased coating rate in the edge regions with which the reduced coating thickness otherwise occurring in the edge regions was compensated.

FIG. 5 shows a representation of the sputtering power used in the deposition of FIG. 4 as a function of a position on a trajectory on the surface of the substrate, the zero point corresponding to the zero point in FIG. The substrate is moved through the deposit under the sputtering source. A certain position on the abscissa in Figure 5 thus corresponds to a time at which the center of the sputtering source is above the position in question. The curve labeled 500 corresponds to a constant sputtering performance, as is common in the prior art. The curve 501 corresponds to the

Sputtering power as a function of the rotation angle of the main drive according to the present invention.

Claims

A method for producing substrates with a plasma-coated surface of a dielectric coating material in a vacuum chamber, which has a powered with an alternating current plasma device with

Moving a substrate relative to the plasma device by means of a

Movement device along a curve,

Depositing coating material on a surface of the substrate in a coating area along a trajectory lying on the surface of the substrate by means of the plasma device, characterized by a) determining actual values of a layer thickness of deposited

Coating material on at least parts of the trajectory in the direction of movement of the substrate, b) comparing the actual values with target values of the layer thickness on the at least parts of the trajectory, c) determining parameters of the plasma device for changing the amount of coating material deposited per unit time as a function of the position of the substrate, such that the actual values of the layer thickness of deposited

Coating material deviate less than a predetermined difference from the target values and d) setting parameters of the plasma device for changing the amount of coating material deposited per unit time according to point c) e) depositing coating material by means of the plasma device with the parameters set in point d).

2. The method according to claim 1, characterized

in that the set parameters of the plasma device are parameters of the power supply and / or parameters of the gas supply of the plasma device and / or parameters of the plasma emission of the plasma device.

3. The method according to claim 1 or 2, characterized by

Removing the substrate from the vacuum chamber according to point a).

4. The method according to claim 3, characterized by

Determining the actual values by measuring in situ in the vacuum chamber according to point a).

5. The method according to any one of claims 3 or 4, characterized by

Determining the actual values by measuring ex situ outside the vacuum chamber according to point a).

6. The method according to any one of the preceding claims, characterized

in that the parameters of the power supply are an electrical current, an electrical voltage and / or a plasma impedance.

7. The method according to any one of claims 1 to 6, characterized

the parameters of the gas supply to the plasma device are a working gas flow and / or a reactive gas flow into the plasma device or into a space between the plasma device and the substrate.

8. The method according to any one of the preceding claims, characterized

the plasma device is designed as a sputter source with one or more sputtering targets or has such a sputtering source and the deposition takes place as sputtering.

9. Method according to one of the preceding claims, characterized in that that the deposition takes place by means of a plasma device, which as targetless

Plasma source is formed or has such a plasma source.

10. The method according to any one of the preceding claims, characterized by

Moving the substrate along a linear curve and / or moving the substrate along a non-linear curve, in particular a curve formed as a circle or arc.

1 1. Method according to one of the preceding claims, characterized by

Move along a curve that is equidistant from the plasma device.

12. The method according to any one of claims 1 to 10, characterized by

Moving along a curve which is non-equidistant with respect to the plasma device, in particular is concave or convex, and

Determining parameters of the plasma device for changing the amount of coating material deposited per unit time according to claim 1 b) until the actual values, preferably excluding the chordal effect, deviate less than a predetermined difference from the desired values.

13. The method according to any one of the preceding claims, characterized by

Selection of the coating material from a group comprising at least one of the elements silicon, aluminum, magnesium, hafnium, zirconium, niobium, tantalum, titanium, scandium and / or their oxides or nitrides.

14. The method according to any one of the preceding claims, characterized by

Determining the actual values by means of a Schichtdickenmeßeinrichtung, wherein the

Layer thickness measuring device designed as a spectrophotometer or ellipsometer, particularly preferably spectral ellipsometer.

15. The method according to any one of the preceding claims, characterized by

Use of a disk-shaped flat or curved substrate.

16. The method according to claim 15, characterized by

Use of a disc-shaped substrate having a largest linear dimension or a largest diameter smaller than a coating window of

Plasma device.

17. A process for producing substrates with a plasma-coated surface from a dielectric coating material in a vacuum chamber by a coating system, which one with an AC-powered

Having a plasma device, with a) providing at least one selectable process profile by means of a

Memory module of a control module, b) selecting one of the provided process profiles by means of an input unit of the control module, wherein the selected process profile is assigned to the control module as an operating configuration, c) controlling the movement means, wherein the plasma source or the substrate by means of the controlled movement means based assigned to the as operating configuration d) acquiring measuring parameters at at least one measuring point of the contour on the surface of the substrate by means of a measuring sensor of the system, e) quantifying the material characteristic parameters determined by the sensor by means of the Control module based on predefined surface classifications, wherein predefined material characteristic parameter ranges are each assigned to a surface classification and wherein the corresponding quantification of the e corresponding surface classification by triggering material characteristic parameter ranges based on the

Material parameter characteristics, f) generating a plasma source control signal by a computing module of the

Control module based on the surface classification and a

Plasma source parameter profile of the process profile characterizing the correlation between the surface classification and the plasma source control signal; g) controlling the plasma source by the plasma source control signal according to the surface classification and plasma source parameter profile of the process profile for depositing coating material on a surface of the substrate in a coating region along a surface of the substrate Trajectory by means of the plasma device.

18. An apparatus for producing substrates (10, 100) having a plasma-coated surface of a dielectric coating material in a vacuum chamber having an alternating current operated plasma device (31, 32, 150, 180) with a moving means for moving a substrate (10, 100) relative to the plasma device (31, 32, 150, 180) along a curve, wherein by means of the plasma device (31, 32, 150, 180) deposition of coating material on a surface (1 1, 101) of the substrate (10, 100) in a coating area along a (12, 105) trajectory lying on the surface of the substrate, characterized by a control module (140) which is designed and arranged for a1) determining actual values of a layer thickness of seasoned

Coating material on at least parts of the trajectory in the direction of movement of the substrate by means of a layer thickness measuring device (1 10), b1) comparing the actual values with target values of the layer thickness provided by a presetting device (120) on the at least parts of the trajectory by means of a comparison device ( 130), c1) determining parameters of the plasma device (31, 32, 150, 180) by means of a computing module (141) of the control module (140) for changing the amount of coating material deposited per unit time as a function of the position of the substrate (10, 100 ) such that the actual values of the layer thickness of

d1) Setting parameters of the plasma device (31, 32, 150, 180) by means of a setting module (142) of the control module for changing the amount of coating material deposited per unit time according to point c1 ) e1) deposition of coating material by means of the plasma device (31, 32, 150, 180) with the parameters set in point d1).