Vacuum system and method for depositing compound layers

Abstract

A vacuum device for depositing a compound layer on at least one plate-like substrate by sputtering, comprising: a vacuum chamber (11) having side walls surrounding a central axis (A), the chamber comprising: at least one inlet (13) for a process gas; at least one inlet (14) for an inert gas; a substrate handling opening (15); a susceptor (5) comprising an electrostatic chuck (6) formed as a substrate (4) support in a central lower region of a sputtering compartment (18), the susceptor (5) being mounted in an electrically isolated manner and connected to a first pole of a first voltage source (21), the susceptor (5) also being movable in a vertical direction from an upper position to a lower position towards and away from a target (1) and vice versa when the sputtering process is active; A magnetron sputtering source (22) comprising a target (1) at the front side of the source and a magnet system (23) at the rear side of the source, the target (1) being mounted in an electrically isolated manner in a central region at the top (19) of a sputtering compartment (18) of a chamber (11) and connected to a first pole of a second voltage source (25), an anode (2) surrounding the target (1) and an upper portion of a pedestal (5) comprising at least a substrate support and an ESC (6) to form a side wall (12) of the sputtering compartment, the anode (2) being electrically connected to ground; a pump compartment (17) connected to the bottom (20) of the sputtering compartment by a flow labyrinth (26) designed to provide substantially the same flow conductance at upper and lower positions of the pedestal and at any position therebetween; a vacuum pump system (16) connected to the pump compartment (17).

Description

Technical Field

[0001] The present application relates to a vacuum device for sputtering deposition of a compound layer according to the present disclosure, a multi-chamber system (MCS) according to the present disclosure and a method for producing an as coated substantially two-dimensional flat substrate according to the present disclosure. Technical Background

[0002] As the miniaturization of piezoelectric devices such as microphones, electrical frequency filters, ultrasonic generators, sensors and actuators continues, the material properties of piezoelectric materials, especially those of piezoelectric layers and coatings, become increasingly important. Such properties are, among others, a uniform and highly oriented microstructure as shown by the θ / 2θ X-ray diffraction pattern and indicated by narrow FWHM values ​​of the rocking curve, and low dielectric loss properties as indicated by low tan δ values. It is well known that the piezoelectric response can be improved by alloying the piezoelectric AlN film with other metals, thereby still retaining the hexagonal structure of the AlN. The most promising material for industrial use is Sc, up to Sc concentrations of up to 43 atomic %. Other known materials are Cr and MgHf.

[0003] However, it has been found that the quality of such coatings in large-scale production depends on very strict reproducibility of the layer parameters, which is directly linked to corresponding device and system requirements and strict process control. Despite many efforts and progress in prior art vacuum equipment, it has not yet been possible to establish appropriate technical conditions to solve all the necessary problems to meet the rapidly increasing demand for higher precision and performance required for the production of coatings for such devices. Summary of the invention

[0004] An object of the present invention is to provide an apparatus and a multi-chamber system (MCS) to enable the deposition of piezoelectric layers and coatings and the production of separately coated substrates such as wafers, thereby providing better process control. Such process control may include better vacuum regimes in terms of minimizing pressure fluctuations during the deposition of the piezoelectric layer, as well as any measures to improve stress control within the piezoelectric layer, as discussed in detail below. With respect to the piezoelectric layer materials as mentioned in the technical background, it should be mentioned that the present invention relates to improvements in any such prior art materials, regardless of the fact that examples and embodiments of the present invention may be discussed due to certain materials for practical reasons.

[0005] The vacuum device of the invention can be used for very different types of layers, but has some design features which will substantially improve process stability and reproducibility when depositing a compound layer on at least one plate-like substrate by sputtering. Such features include:

[0006] A vacuum chamber having side walls surrounding a central axis (A), the chamber comprising

[0007] - at least one inlet for a process gas;

[0008] - at least one inlet for an inert gas;

[0009] - substrate handling opening;

[0010] - a pedestal comprising an electrostatic chuck formed as a substrate support in a central lower zone of the sputtering chamber, the pedestal being mounted in an electrically isolated manner and connected to a first pole of a first voltage source, for example by means of a switch controlled by a system control unit of the device, thereby constituting together with the electrostatic chuck (ESC) a bias electrode; when the sputtering process is active, the pedestal is movable in the vertical direction towards and away from the target from an upper processing position to a lower processing position and vice versa, which makes it possible to control the film stress on the substrate over the target lifetime and to compensate for the developing target erosion.

[0011] a magnetron sputtering source comprising, at the front side facing the sputtering chamber, for example a metal or alloy target and at the rear side of the source, a magnet system, which may additionally be provided with a cooled backing plate and / or, for example, a water-cooled flange between the target material and the magnet system; the target is mounted in an electrically isolated manner in a central zone in the top region of the sputtering chamber of the chamber and is connected, for example, by a further electrical switch controlled by a system control unit of the device, to a first pole of a second voltage source, thereby forming a sputtering surface of a sputtering electrode; a substantially cylindrical anode, which surrounds the target and at least the upper part of a base comprising a substrate support and an ESC, thereby forming a side wall of the sputtering chamber, said anode being electrically connected to ground;

[0012] a pump compartment connected to the bottom of the sputtering compartment by a flow labyrinth to prevent so-called "overflow" of plasma from the sputtering compartment into the pump compartment, wherein the entry of plasma into the pump compartment has well-known disadvantages such as process instabilities, parasitic losses of plasma power and potential damage to pumping equipment; the flow labyrinth is designed to provide substantially the same flow conductance in the upper and lower positions of the pedestal and in any position therebetween;

[0013] A vacuum pump system (16) connected to the pump compartment (17).

[0014] As known to those skilled in the art, the movement of the susceptor during the sputtering process may be achieved by a stepper motor or other positioning means controlled by a system control unit.

[0015] One design to achieve such a flow labyrinth feature may be to provide a flow labyrinth having the same flow area during movement from an upper position to a lower position. In yet another embodiment, the flow labyrinth may include at least one annular pump channel that surrounds the susceptor in the region below the substrate support and the ESC. Thus, at least one characteristic distance (w) between at least two cylindrical or / and annular walls of the pump channel may be greater than or equal to 0.1 mm. ch ) can remain constant in the upper and lower processing positions of the base and in any position therebetween. Such a labyrinth feature can be combined with all embodiments of the present invention.

[0016] In yet another modification, the apparatus may have an electrically isolated target ring mounted around the circumference of the target between the target and the anode. The target ring may be made of an electrically conductive material, such as a metal, alloy or carbon, and isolated from ground and target potential by at least one isolator, the isolator being hidden from any view towards the sputtering chamber, for example by the anode and / or the target shield. While observing the dark space distance between each adjacent conductive component, such as the target and the target ring and the target ring and the anode, for typical process pressures between 0.1 and 13.3 Pa (1-100 mTorr) used in the sputtering process, the dark space distance may be between about 2 and 10 mm. This ensures that a floating potential is formed on the target ring for a long time during the sputtering process without the need to change the isolator due to the formation of the conductive surface area. The at least one, for example at least partially ring-like isolator may be located on the anode or in the channel structure of the anode and may comprise a ceramic material such as aluminum oxide, boron nitride, etc.

[0017] In yet another embodiment, an annular ring shield is electrically isolated and mounted to the pedestal and surrounds the substrate support, the wafer mounted on the support, and optionally the ESC. The ring shield of the apparatus of the present invention can be connected to a third voltage source to adjust the voltage according to process needs, which can be used as yet another variable affecting the film stress of the sputtered layer.

[0018] The ESC surface and / or the base surface may include an open structure of several microns or even submicron depth, which is connected to at least one corresponding back gas inlet. When both surfaces include an open structure connected to the back gas inlet, a heat transfer inert gas such as Ar can be applied between the ESC surface and the mounted substrate to control the substrate temperature, and a heat transfer inert gas such as Ar can be applied between the base surface and the ESC to control the ESC temperature. Thus, at least one of the two back gas inlets can be connected to a common feedthrough, or can be connected to corresponding separate feedthroughs when different back gas pressures should be used. Thus, a common or corresponding separate gas supply for cooling / heating gas is connected to a common or separate feedthrough to control the substrate and / or base temperature. The open structure can be referred to as a so-called round table (mensa) structure, with many support points, such as a table, evenly spread on the corresponding surface, or can be a channel structure, such as a spider web or a maze, in the surface of the ESC and / or the base. Both structures can be applied to the surface, for example by laser structuring of the surface. With a separate pressure supply and feed-through, a higher back-gas pressure can be selected between the base and the ESC, thus allowing for a faster heat exchange.

[0019] In order to deposit piezoelectric compounds, the target may contain at least one metal element such as Al to deposit AlN, or at least two metal elements such as Al and Sc to deposit AlScN, Al and Cr to deposit AlCrN or Al, Mg and Hf to deposit AlMgHfN. The process gas will contain nitrogen as a reactive gas. The target may be an alloy target or a powder metallurgy pore-tight sintered target. Porous sintering refers to a target whose density is close to the theoretical density, which can be achieved, for example, by spark plasma sintering.

[0020] The anode may be manufactured as a single-piece anode to achieve a uniform heat flow in the anode. In addition, it is foreseeable that the anode has a heating / cooling circuit connected to a heating / cooling unit to temper the anode during pumping or idle time and cool the anode during the sputtering process. In addition, gas supply means may be installed along or around the upper or lower circumference of the anode. Such gas supply means may include at least one of the following: a gas ring with distributed openings distributed along its inner, outer, upper or lower circumference, and a channel structure integrated in the anode with circular distributed gaps or respectively distributed inlet openings and / or other inlet channels. The channel structure is foreseeable to be the top of the anode close to the target, whereby a channel can be formed in the anode itself or between the anode and a floating target ring, which can be seated in the channel.

[0021] The first voltage source may be a first RF power supply which may be driven between 2-30 MHz, whereby for many cases a 13.56 MHz power supply will be sufficient.

[0022] The second voltage source may be a pulsed DC power supply, or a DC power supply combined with a second RF power supply. When a DC power supply is combined with a second RF power supply, at least the DC power supply is connected to the sputtering electrode through an adapter network, such as a low-pass filter, to protect it from harmful input RF. In order to adjust the phase relationship between the first RF source and the pulsed DC power supply or the second RF source, the device may include adjustment measures. These can be implemented by an adjustment unit integrated into the system control unit (SPU) or in the form of a sub-control unit connected to the SPU. Thereby, the in-phase mode or the defined out-of-phase mode can be adjusted according to the process needs. The pulsed DC power supply can be driven in the frequency range of 50 to 400kHz, with a duty cycle of 50 to 90% and a power of 7 to 14kW.

[0023] Furthermore, the device may comprise control measures to control the flow of the reactive gas as a function of at least one of the following process parameters: target voltage, characteristic parameters of the plasma emission from the active sputtering surface of the target, gas composition. The characteristic parameter of the plasma emission may be, for example, the intensity of a characteristic emission line or a characteristic line pattern measured by a plasma emission monitor (PEM). The gas composition may be measured by a process gas analysis system such as an RGA.

[0024] In order to avoid parasitic plasma around at least one of the ESC, the pedestal and the RF powered portion of the pedestal base, a dark space shield connected to ground is provided at a dark space distance around at least the base of the pedestal, as described above. Such a dark space shield may form one side wall of the pump channel and may move with the pedestal. A second outer side wall forming such an annular pump channel may be formed relative to the central axis A by a second channel shield mounted to the dark space shield and movable therewith or alternatively mounted to or being part of a fixed anode.

[0025] In addition, at least one of the susceptor temperature and substrate temperature measuring devices should be provided, for example, to control the susceptor temperature with an electrical temperature measuring device and / or to control the substrate temperature with an optical measuring device such as a pyrometer at the backside surface of the substrate. Such temperature measuring devices are used to control the substrate temperature, for example via the SPU and a heating and cooling unit, which is connected to the corresponding heating and cooling fluid circuit under the support surface of the susceptor and / or the ESC. It should be mentioned that one heating and cooling unit to supply the susceptor, the anode and the magnetron sputtering source to temper or cool the backing plate or target flange may be sufficient for standard processes. However, for processes requiring stricter temperature control, a separate heating and cooling unit for the susceptor will be more suitable, and a separate cooling / tempering unit for the magnetron source and the anode will be more suitable. Thus, strict temperature control of the susceptor and therefore the substrate has been proven to be a key to produce highly textured compound layers. For high deposition temperatures, for example above 100°C, a resistive heating plate can be integrated in the susceptor or on the surface of the susceptor as a supplement or alternative to the heating and cooling unit.

[0026] In yet another modification, the target is composed of at least one of the following materials or a mixture thereof:

[0027] - Aluminium, which represents Al or AlMe,

[0028] - Aluminum-scandium, which represents AlSc or AlScMe,

[0029] - aluminum-chromium, which represents AlCr or AlCrMe,

[0030] - magnesium-hafnium, which represents MgHf or MgHfMe,

[0031] Whereas Me represents at least one further, for example secondary metal, whose concentration is from 0.1 to 10 atomic % relative to the total metal content of the corresponding layer, a mixture of two primary metals such as AlSc, AlCr or MgHf always contains a lower concentration of at least 1% of the primary metal, regardless of whether any other secondary metal Me is present.

[0032] The present invention also relates to a multi-chamber vacuum system (MCS) for processing at least one plate-like substrate, which comprises at least one loading lock chamber, a transfer measure and at least three processing modules, wherein the first processing module may be a PVE module (P1) configured to etch the surface of the substrate, the second processing module may be a metal sputtering module (P2) configured to deposit a metal layer by sputtering onto the surface of the substrate, and the third processing module may be a compound sputtering module (P4) configured according to the device of the present disclosure.

[0033] The MCS system may further include a fourth processing module, which may be configured to heat the substrate to an annealing temperature T between 550° C. and 900° C.A It can be configured to heat the substrate to the annealing temperature T within 60 to 180 seconds. A Annealing module (P3).

[0034] In yet another embodiment, the MCS system may further comprise at least one additional PVE module (P1'), at least one of a metal sputtering module (P2'), and a compound sputtering module (P4').

[0035] For any such MCS embodiment, at least one load lock chamber and processing modules (P1, ... P4') can be arranged in a circular or polygonal manner around a central handler chamber. In an alternative embodiment, the load lock chamber and processing modules (P1, ... P4') can be arranged in a linear manner and the handler can be a linear handler, such as at least one conveyor belt or conveyor chain.

[0036] For such an MCS implementation, the pre-processing and post-processing modules (pp 12 ,pp 34 ,pp 56 ) can be operably connected to at least one of the load lock chambers.

[0037] The present invention also includes a method of producing a coated substantially two-dimensional flat substrate, such as a wafer, by a sputtering process, whereby a target containing aluminum is sputtered in an apparatus as discussed above. Thus, the piezoelectric AlN film can be coated with at least one secondary metal Me m Alloying improves the piezoelectric response, while still retaining the hexagonal structure of AlN. f It may be at least one of Sc, Cr, Mg or Hf, which can be alloyed with a sputtered aluminum target. Such a method may include depositing at least one piezoelectric layer. The layer may be composed of at least one of the following materials or a mixture thereof:

[0038] -Aluminum nitride (AlN, AlMeN),

[0039] -Aluminum-scandium nitride (AlScN, AlScMeN),

[0040] -Aluminum nitride-chromium (AlCrN) or

[0041] -Magnesium hafnium nitride (MgHfN, MgHfMeN),

[0042] Me represents at least one, for example secondary, metal whose concentration is 0.1 to 10 atomic % relative to the total metal content of the corresponding layer.

[0043] The first voltage source connected to the bias electrode can be a first RF-source driven at a frequency of 2 to 30 MHz, using a very moderate bias power of 0 to 100 W or even lower 0 to 30 W to avoid disturbing the growth of the corresponding piezoelectric layer. And the second voltage source connected to the target electrode can be a pulsed DC-source driven at a pulse frequency of 50 to 400 kHz, with a power of 7 to 14 kW. In addition, a positive voltage can be applied during the disconnection period. Alternatively, the second voltage source can include a DC-source and a second RF-source connected to each other and to the target electrode through an adapter network, whereby the second RF-source can be driven at a pulse frequency of 0.9 to 30 MHz.

[0044] In order to optimize certain characteristics of the layer, which may be to minimize and / or equalize as much as possible the stress and / or stress distribution of the individual sputter-deposited layers of the coating on the wafer surface, at least one of the following process parameters may be alternated stepwise or continuously, e.g. in a series of processes according to subsequent thickness or stress measurements and / or in a process by in-situ process control, e.g. according to optical film thickness measurements or corresponding in-situ stress measurements:

[0045] - the power of the first voltage source,

[0046] - the power of the second voltage source,

[0047] - the duty cycle of the pulsed DC-source,

[0048] - the quotient of the power of the DC-source and the second RF-source,

[0049] - the distance between the substrate surface and the target surface, which can also be used effectively to balance the effect of target erosion over several process cycles,

[0050] - a defined (DC, RF) voltage applied to the isolated ring shield,

[0051] - high deposition temperature of the piezoelectric layer,

[0052] - an annealing step of annealing at least the seed layer and / or the bottom layer.

[0053] Furthermore, the layer or coating characteristics mentioned merely by way of example can be adjusted by the above-mentioned process parameters, such as the rocking curve of the wafer, which can be measured with diffraction topography methods such as plane wave topography, in particular the corresponding continuous topography along the rocking curve. A good approximation that can be used instead is to determine the full width at half maximum (FWHM) of certain characteristic crystal lines of the corresponding measured x-ray diffraction pattern.

[0054] The above also relates to the surface roughness contribution of the coating layer and the dielectric loss, which quantifies the intrinsic electromagnetic energy dissipation of the layer and can be given by the loss angle δ or the corresponding loss tan δ. Examples are given below.

[0055] Examples and drawings

[0056] The invention will now be further illustrated with the aid of examples and drawings. The drawings are all drawn schematically and in a simplified manner only, the same reference numerals designating features of the same or similar function. As with upwards, on, below and above or left and right, with regard to the terms top or bottom, it should be mentioned that such terms are used for ease of use or only with reference to the drawings and not in a restrictive manner, so that the top and bottom configurations as presented, in which the wafer and the target are in a relative horizontal position, can also be applied, for example, to left-right configurations, and vice versa, if the same inventive concept is to be applied to another type of device in which both the target and the substrate are in a vertical or inclined position. It also relates to cylindrical and ring-like structures resulting from the corresponding design of the examples shown, which can also be transferred to other chamber symmetries, for example, (right) angled geometries.

[0057] The accompanying drawings show:

[0058] Figure 1 : An embodiment of the device according to the present invention;

[0059] Figure 2 : An implementation scheme of a flow maze;

[0060] Figure 3 : Another implementation scheme of the flow maze;

[0061] Figure 4 : Another implementation scheme of the flow maze;

[0062] Figure 5 : Details of the flow maze;

[0063] Figure 6 :flow chart;

[0064] Figure 7 : Base with dual cooling / heating gas supply;

[0065] Figure 8 : MCS of the present invention arranged in a circular pattern;

[0066] Fig. 9 : Linearly arranged MCS of the present invention.

[0067] Figure 1 A schematic diagram of a sputtering device according to the invention is shown, which comprises a two-part vacuum chamber 10 divided into a sputtering compartment 18 and a pump compartment 17, both of which are connected in terms of gas flow by a flow labyrinth 26. In this embodiment, the device has a substantially cylindrical arrangement about the device axis A. The target diameter r of the anode 2 forming the side wall of the sputtering compartment 17 is t and inner diameter r aThe target diameter r can be selected according to the substrate, for example, according to the wafer size. For a 200 mm wafer, the target diameter r t The inner diameter can be selected from 250 to 400 mm. a Can be selected from 300 to 450 mm. The side wall 11 is designed as the cathode 2 of a magnetron sputtering source 22, which comprises a target 1 and a magnet system 23 at the top of the sputtering chamber 18. In case the target material is expensive or mechanically weak, a target backing plate 24 may further be provided. Between the target 1 and the cathode 2, the isolated mounted, yet conductive target ring 3 is positioned on a ceramic isolator 43 in the form of a ring or a ceramic support, which is arranged in the upper circumference of the anode 2 around the target 3. The target ring 3 is at floating potential. The isolator 43 is hidden from any view towards the sputtering chamber 17 in a channel structure 34, which together with the inlet gap 35 provides an inlet 13 for a process gas, which may be a reactive gas, a mixture of different reactive gases, with or without the addition of a diluting inert gas. In the case of Figure 1 In the embodiment shown in , an inlet gap 35 is formed between the anode and the target ring 3. An alternative or additional inlet for process gas may be provided near the lower circumference of the anode in the form of a gas ring 33. Thus, the process gas and inert gas supplies may be separated, which may help prevent target poisoning when, as an example, process gas is only supplied via the remote gas ring 33 (which may be located in the pump compartment 17 as shown), while only inert sputtering gas is provided to the upper inlet 13.

[0068] A vertically movable RF-pedestal is installed in the bottom of the sputtering chamber 18, see reference numeral 5 and the vertical double arrow, which includes an electrostatic chuck 6 to fix the wafer 4 and the pedestal base 5'. The ring shield 7 and the dark space shield 8 can move up and down with the pedestal. The ring shield 7 and the dark space shield 8 are both electrically isolated from the RF potential of the pedestal and / or separated from the corresponding RF support part of the pedestal 5 and the pedestal base 5' by a dark space distance. However, the dark space shield 8 is at ground potential, while the ring shield 7 is at a floating potential or is provided with a separate voltage source to form a third electrode in the sputtering compartment 18. In addition to other known measurements such as target power and substrate bias, such a third electrode 7 around the circumference of the wafer can also be used to optimize the stress and stress distribution in each layer of the piezoelectric active coating. Via corresponding feedthroughs 32, the pedestal is connected to an RF line 41 and a fluid line 42 for heating and cooling the pedestal 5 and the ESC 6. The temperature at the back side of the wafer 4 is controlled using an optical temperature measuring device 40, such as a pyrometer, which requires an additional optical feedthrough 32. A pump socket is provided at the bottom or side wall 11 of the pump compartment 17 for connection to a high vacuum pump system 16.

[0069] Figures 2 to 5Different modifications of the flow labyrinth 26 are shown. All parts connected to the susceptor 5 or its base 5', such as the electrically isolated annular shield 7 and the dark space shield 8, move with the susceptor, while the anode 2 and the channel shield 9 are fixed. For reasons of process stability, it will be important to keep the pressure fluctuations as low as possible. Therefore, it is important to provide the same pumping speed at every process-relevant position of the susceptor, which positions do not necessarily include potential loading and unloading positions, such as the lowest or highest possible positions. The typical process-relevant travel of the susceptor during the entire target life may be in the range of 40mm to 90mm for thick targets, and for a typical 6mm target, the travel will be in the range of about 15mm to 40mm, so a travel of 15mm to 90mm will be sufficient for any need. All types of labyrinths 26 include at least one annular pump channel 27.

[0070] Importantly, during the travel, the characteristic distance (w ch ), such as the characteristic width of the channels within the labyrinth (which defines the minimum flow area), will not change but remain constant. To illustrate the situation where a simple flow labyrinth is created between the sputtering compartment 18 and the pumping compartment 17, Figure 5 1 and 2 show some distances I, II, III, IV which may become characteristic distances within a certain travel distance of the susceptor. In this embodiment, the total travel of the susceptor is 95 mm and is designed for a process-related travel of 40 mm (from 65 to 95 mm, the highest possible position of the susceptor). ai 110cm between 2 Under constant vacuum and pumping conditions defined by the cross section, see Figure 6 In this range, the distance I defines the constant characteristic distance w of the maze. ch , and enables the wafer to be moved towards and away from the target surface to compensate for target corrosion and / or control layer stresses in the corresponding layer stack of the coating. If the travel value is lower, the distance II becomes a characteristic value of the flow labyrinth 26, as shown by the thick broken line of the characteristic curve V. However, in this lower range, when the base fin approaches the plane of the lower inner circumference of the anode, as the distance II becomes smaller, the flow area will constantly decrease (dashed line). At the lower end of the travel (not shown in the figure), the distance III becomes a characteristic value before the base travels zero mm and sits at the anode. For Figures 2 to 5 , the gas inlet 13 is integrated into the anode 2 rather than between the anode 2 and the target ring 3. However, Figure 1 A similar configuration of the anode integrated gas inlet of the embodiment of the present invention can also be used for Figures 2 to 5 ,vice versa. Figure 5The horizontal dashed line in shows an alternative higher position of the upper surface of the ring shield 7, which may have some benefits under certain process parameters and may likewise be combined with any embodiment of the actual invention. Thus, the upper surface of the ring shield may be coplanar with the chuck 6 or the substrate surface or any position between the two.

[0071] Can be used for Figure 3 and 4 Similar considerations apply to the labyrinth 26 shown, which contain one and two 180° turns respectively in the flow channel and will therefore be very effective in preventing any plasma from spilling from the sputtering compartment to the pumping compartment, as long as the slit width at the labyrinth entrance meets the dark space distance requirements according to the corresponding vacuum conditions or is covered by a grid of corresponding size. Figure 3 In the embodiment, the dark space shield 8 is formed into a groove shape, and the channel shield 9 is positioned at the center of the groove, together defining a U-shaped flow channel. Figure 4 In the sputtering chamber, the channels are integrated in the channel shield 9, where they form part of the anode 2. They are positioned at the anode radius r in the sputtering chamber. a and the lower anode radius r ai The lower anode radius r ai In this case the dark space shield 8 is at a dark space distance. The integration of a part or the whole labyrinth 26 in the anode shield 2, for example as an integral component or at least as a close thermal coupling, has advantages in terms of a more uniform temperature distribution in the sputtering chamber. Figure 4 In the embodiment, the channel from the sputtering compartment 18 splits laterally into two S-bends, exiting into the pump compartment 17. In this case, the characteristic distance w ch =w ch1 +w ch2 , where w ch1 、w ch2 It can be defined as the width of the corresponding subchannel with curved flow arrows.

[0072] For a sputtering compartment with a volume of 30 liters for all types of labyrinths, a pumping speed of 500 to 700 l / s should be adjustable. For a high vacuum pump system 16, for example a system comprising a turbomolecular pump connected to the pump socket 44 of the pump compartment 17, this translates into a pumping speed of about 2000 l / s due to the flow resistance of the respective labyrinth 26 used.

[0073] Figure 7A detail of a susceptor 5 of the invention is shown, which is provided with two inlets 16 for inert heating / cooling gases, namely one backgas inlet 30 for the wafer and one backgas inlet 31 for the ESC when fixed to the ESC. Respective inlet channels 14 connect the gas inlets with a feedthrough 32 at the bottom of the susceptor base 5'. Such a configuration has some advantages compared to a configuration with only one inlet for both systems, because the backpressure of the ESC can thereby be raised to higher values, while the backpressure of the wafer is very limited, for example for 200 mm wafers, the backpressure is limited to a maximum of 5 sccm, to avoid arcing that would occur at higher flow rates, because only the wafer 4 separates the inlet 30 and the channel 29 from the high vacuum of the sputtering chamber. Using such a configuration, the ESC 6 can have a surface patterned by channels 29 open to the wafer, so as to increase its flow resistance when the heating / cooling gas flows from the inlet 31 under the wafer to the outer area of ​​the ESC 6, where it can escape into the high vacuum of the sputtering chamber, see the upper horizontal arrow. The surface pattern can be any kind of maze pattern, such as a spider web, spiral, meander or round table-like pattern of open channels 29, with very low channel heights of a few μm or even lower to keep the flow resistance high. Thereby a uniform gas distribution at the wafer backside and a uniform distribution of the support points or areas of the wafer support can be achieved to avoid any mechanical stress due to electrostatic forces of the ESC 6. Ultimately, for example for wafers with a size of ≥ 200 mm, combined with multiple inlets 30 at different points on the ESC surface, the cooling and heating of the wafer backside can be achieved most efficiently even at low backgas flow rates and pressures, since the combination of high support area and uniformly spread shallow channel cavities provides short paths for gas molecules between the cold / hot ESC-surface wafers.

[0074] The inlet channel 14 from the feedthrough 32 to the back gas inlet 31 for cooling / heating the underside of the ESC ends in an open channel 28, which is here recognized as a back gas chamber 28 between the base and the ESC. From there, the back gas can flow out to the pump compartment 17 via the needle channel 48 and the base channel 49, as indicated by the curved arrow and the horizontal arrow below, both of which provide high flow resistance to achieve a relatively high back pressure between the base 5 and the ESC 6, which can be about 0.1 to 1 hPa (10 -1 –10 0 mbar). Heating of the chuck 5, which is made of insulating ceramic material and comprises at least one RF-electrode 47, is provided by a heating plate 46 on the base 5' of the chuck. Alternatively or additionally, a water-cooled chuck may be used.

[0075] Figure 8 FIG. 5 shows a multi-chamber system MCS 50 comprising four processing modules P 1 To P 4 and up to six pre-processing or post-processing modules pp12 To pp 46 , the latter being positioned in pairs above and below the wafer handling level. All modules are arranged in a circle or polygon around a central carrier compartment 51, which contains freely programmable carriers 52 to transfer wafers from the pre-processing module to the processing module, between modules, and finally back to the post-processing tool. Transfers in and out of the MCS are accomplished by load locks 53 for input wafers and load locks 54 for output wafers. At least one additional carrier transfers wafers from a load lock chamber 55 (here known as a load lock section) to the pre-processing module pp 12 And then from the post-processing module pp 56 Transfer back to the load lock section. Pre- and post-processing modules pp 12 ,pp 34 ,pp 56 At least one of a buffer, a heating station, a cooling station and an alignment station for allowing the wafer to wait for processing or transfer may be included. When annealing should be performed in the MCS, the processing module as presented shows a minimum configuration. Therefore, module P1 includes a PVE-station, P2 (metal sputtering station) and P3 (annealing chamber), which includes a flat carbon heater facing the substrate surface to be heated. The top and bottom of the annealing compartment include cooled reflector surfaces, whereby the substrate is kept close to its outer circumference by a three-finger support. Finally, module P4 includes a compound sputtering device 10 of the present invention as described above. Other modules, such as a second compound sputtering module for the thickest layer system of the coating to speed up the overall process time by dividing the sputtering time into two, or a second metal sputtering module for a layer system including two or more metal electrodes, can be connected via a docking station 56.

[0076] The system control unit 36 ​​of the MCS, which may include the respective system units of the modules or at least control the timing of such units, controls the wafer transfer and the process details within each module through control measures 38, regulation measures 37, measurement measures 40 and sensors (not shown), which measures may also be at least partially included in the system control unit 36 ​​or separated from the respective module to be controlled. An input / output unit 39 allows the operator to modify individual process parameters and automatically load new processes.

[0077] Fig. 9 Schematically, an MCS 50' with a linear module arrangement is shown in FIG. In this case, for each process step, a separate module is provided between a load lock 53 for input wafers and a load lock 54 for output wafers, and respectively dedicated load lock chambers 55' and 55" are provided, which chambers may contain pre-processing and post-processing modules or may also be connected to such modules (see FIG. Figure 8). When the substrate has been transferred from the load lock chamber 55' to the PVE-module 1', the process starts with the etching of the clean blank wafer surface, followed by a sputtering process in module P4' to deposit a thin compound layer as a seed layer, onto which the first metal layer Me1 is applied in module P2. This is followed by an annealing step in module P3, a further PVE step in P1 to refine the metal surface, a further compound sputtering step in module P4 to apply a functional piezoelectric layer Comp1 to the etched metal layer Me1, and finally a second deposition of a second metal layer Me2 in module P2' to complete the layer stack with the second electrode, after which the substrate is locked out of the vacuum via the load lock 54. Wafer transfer between modules and between modules and the load lock chambers 55', 55" is performed by a linear transporter 52'.

[0078] Reference numerals

[0079] 1. Target, sputtering electrode

[0080] 2 Anode

[0081] 3 floating target ring

[0082] 4 chips

[0083] 5RF Base

[0084] 5' Base Base 6 Electrostatic Chuck (ESC)

[0085] 7-ring shield

[0086] 8 Dark Space Shield

[0087] 9-channel shield

[0088] 10Sputtering device

[0089] 11 Vacuum chamber

[0090] 12 Sidewall

[0091] 13 Inlet process gas 14 Inlet channel inert heating / cooling gas

[0092] 15 Substrate handling opening

[0093] 16 Vacuum pump system

[0094] 17 pump compartments

[0095] 18 Sputtering chamber

[0096] 19 Top of the sputtering compartment

[0097] 20 Bottom of the sputtering compartment

[0098] 21 First voltage source

[0099] 22 Magnetron sputtering source

[0100] 23 Magnet system

[0101] 24 Backplane

[0102] 25 Second voltage source

[0103] 26 Flowing Maze

[0104] 27 annular pump channel

[0105] 28 open channel base / ESC

[0106] 29 open channel ESC / chip

[0107] 30 back gas inlet wafer

[0108] 31 Back gas inlet ESC

[0109] 32 Feedthrough

[0110] 33 Gas ring, inlet process gas

[0111] 34-channel structure

[0112] 35 Entrance Clearance

[0113] 36 central processing units

[0114] 37 Adjustment measures

[0115] 38 Control measures

[0116] 39I / O-device

[0117] 40 Temperature measurement devices

[0118] 41RF line

[0119] 42 Heating and cooling circuits

[0120] 43 Isolator

[0121] 44 Pump socket

[0122] 45 base fins

[0123] 46 Heating Plate

[0124] 47RF-Electrode

[0125] 48-pin channel cooling / heating

[0126] 49-channel chuck heater

[0127] 50 Multi-chamber System (MSC)

[0128] 51 carrier compartment

[0129] 52 transporter

[0130] 53 Loading lock

[0131] 54 Loading lock out

[0132] 55 Loading lock section

[0133] 56 Docking Station

[0134] Me m Minor metal Me (preferably minor) metal, concentration 0.1 to 10 atomic % P 1 …P 4 Processing Module

[0135] pp 12 …pp 56 Pre-processing and post-processing modules t Target radius

[0136] r a Anode radius

[0137] r al Lower anode radius

[0138] w ch Width of the pump channel.

Claims

1. A vacuum device for depositing a compound layer on at least one plate-like substrate by sputtering, the vacuum device comprising: A vacuum chamber (11) having a side wall surrounding a central axis (A), the chamber comprising: - at least one inlet (13) for a process gas; - at least one inlet (14) for an inert gas; - a substrate handling opening (15); - a pedestal (5) comprising an electrostatic chuck (6) formed as a support for the substrate (4) in a central lower zone of the sputtering chamber (18), the pedestal (5) being mounted in an electrically isolated manner and connected to a first pole of a first voltage source (21), the pedestal (5) also being movable in a vertical direction towards and away from the target (1) from an upper position to a lower position and vice versa when the sputtering process is active; a magnetron sputtering source (22) comprising a target (1) at the front side of the source and a magnet system (23) at the rear side of the source, the target (1) being mounted in an electrically isolated manner in a central region at the top (19) of the sputtering compartment (18) of the chamber (11) and connected to a first pole of a second voltage source (25), an anode (2) surrounding the target (1) and at least an upper portion of the pedestal (5) comprising the substrate (4) support and the electrostatic chuck (6), thereby forming the side wall (12) of the sputtering chamber, the anode (2) being electrically connected to ground; a pump compartment (17) connected to the bottom (20) of the sputtering compartment by a flow labyrinth (26) designed to provide substantially the same flow conductance at the upper and lower positions of the base and at any position therebetween; a vacuum pump system (16) connected to the pump compartment (17); Wherein, a dark space shield (8) connected to the ground is provided at least around the base (5') of the base (5) at a dark space distance, and the dark space shield (8) forms a side wall of the annular pump channel and can be moved together with the base, wherein a second channel shield (9) forms an outer side wall relative to the central axis A, thereby being able to form the annular pump channel, and the second channel shield is installed to the dark space shield (8) and can be moved therewith.

2. The device according to claim 1, characterized in that The flow labyrinth is designed to have the same flow area while moving from an upper position to a lower position of the base and at any position therebetween.

3. The device according to claim 1 or 2, characterized in that: The flow labyrinth includes the annular pump channel (27) that surrounds the pedestal in an area beneath the substrate support and the electrostatic chuck.

4. The device according to claim 3, characterized in that At least one characteristic distance (w) between at least two cylindrical and / or annular surrounding walls (2, 8, 9) of the annular pump channel ch ) is constant at the upper and lower positions of the base (5) and at any position therebetween.

5. The device according to claim 1 or 2, characterized in that: An electrically insulating target ring (3) is mounted around the circumference of the target (1) between the target and the anode.

6. The device according to claim 5, characterized in that The target ring is made of a conductive material and is isolated from ground and target potential by at least one ceramic ring which is hidden from any view towards the sputtering chamber.

7. The device according to claim 1 or 2, characterized in that: A ring shield (7) is mounted to the base in an electrically isolated manner, surrounding the substrate support and the mounted substrate.

8. The device according to claim 7, characterized in that The ring shield (7) is connected to a third voltage source.

9. The device according to claim 1 or 2, characterized in that: At least one of the pedestal surface and the electrostatic chuck surface includes an open channel (28, 29) connected to a respective back gas inlet (30, 31).

10. The device according to claim 9, characterized in that Both surfaces contain open channels with back-gas inlets.

11. The device according to claim 10, characterized in that Both back gas inlets are connected to a common or respectively individual feedthrough (32) to a common or respectively individual gas supply.

12. The device according to claim 1 or 2, characterized in that The target includes at least one metal element.

13. The device according to claim 12, characterized in that The target includes at least two metal elements.

14. The device according to claim 12, characterized in that The target is an alloy target or a powder metallurgy sintered target.

15. The device according to claim 1 or 2, characterized in that The anode is manufactured as a one-piece anode.

16. The device according to claim 1 or 2, characterized in that Gas supply means are installed along or around the upper circumference or the lower circumference of the anode.

17. The device according to claim 16, characterized in that The gas supply means comprises at least one of the following: a gas ring (33) with distribution openings distributed along its circumference, and a channel structure (34) integrated in the anode with circular distribution gaps (35) or respectively distributed distribution openings and / or other distribution channels.

18. The device according to claim 1 or 2, characterized in that The first voltage source is a first RF power source.

19. The device according to claim 1 or 2, characterized in that The second voltage source (25) is a pulsed DC power source, or a DC power source and a second RF power source, wherein at least the DC power source is connected to the sputtering electrode via an adapter network.

20. The device according to claim 19, characterized in that The apparatus includes adjustment means (36) for adjusting the phase relationship between the first RF source and the second RF source.

21. The device according to claim 1 or 2, characterized in that The device comprises control means (37) to control the flow rate of the reactive gas according to at least one of the following process parameters: target voltage, intensity or line pattern of plasma emission measured at the active sputtering surface of the target, gas composition.

22. The device according to claim 1 or 2, characterized in that At least one of a susceptor temperature or substrate temperature measuring device (38) is provided.

23. The device according to claim 1 or 2, characterized in that The target is composed of at least one of the following materials or a mixture thereof: -Al or AlMe, -AlSc or AlScMe, -AlCr or AlCrMe, -AlMgHf or AlMgHfMe, Whereas Me represents at least one further metal whose concentration is 0.1 to 10 atomic percent relative to the total metal content of the corresponding layer, the mixture of two or three main metals AlSc, AlCr or AlMgHf always contains the lower main metal in a concentration of at least 1%.

24. A multi-chamber vacuum system for processing at least one plate-like substrate, the system comprising at least one loading lock chamber, a transfer device (52) and at least three processing modules, wherein the first processing module is a physical vapor etching module (P1) configured to etch the surface of the substrate, the second processing module is a metal sputtering module (P2) configured to deposit a metal layer by sputtering onto the surface of the substrate, and the third processing module is a compound sputtering module (P4) configured according to any one of claims 1-23.

25. The multi-chamber vacuum system of claim 24, comprising a fourth processing module configured to heat the substrate to an annealing temperature T between 550°C and 900°C. A Annealing module (P3).

26. The multi-chamber vacuum system according to claim 25, characterized in that The annealing module is configured to heat the substrate to the annealing temperature T within 60 to 180 seconds. A .

27. The multi-chamber vacuum system according to any one of claims 24 to 26, characterized in that It comprises at least one of at least one additional physical vapor etching module (P1'), a metal sputtering module (P2') and a compound sputtering module (P4').

28. The multi-chamber vacuum system according to any one of claims 24 to 26, characterized in that The load lock chambers (55) and the processing modules (P1, ...P4') are arranged in a circular or polygonal manner around the central carrier chamber (51).

29. The multi-chamber vacuum system according to claim 28, characterized in that The load lock chambers (55', 55") and the processing modules (P1, ... P4') are arranged in a linear manner and the carrier is a linear carrier.

30. The multi-chamber vacuum system of claim 29, wherein the linear carrier is at least one conveyor belt or chain.

31. The multi-chamber vacuum system according to any one of claims 24 to 26, characterized in that: Pre-processing and post-processing modules (pp 12 ,pp 34 ,pp 56 ) is operably connected to at least one of the load lock chambers (55, 55', 55").

32. Method for producing a piezoelectric coating on at least one side of at least one plate-shaped substrate (4), the method comprising a sputtering process performed on an apparatus according to any one of claims 1 to 23 or a multi-chamber vacuum system according to any one of claims 24 to 31.

33. The method according to claim 32, characterized in that Depositing a piezoelectric AlN film or containing at least one secondary metal Me m and / or scandium, thereby retaining the hexagonal structure of the AlN.

34. The method according to claim 32 or 33, characterized in that The layer comprises at least one of the following materials or a mixture thereof, or consists of at least one of the following materials or a mixture thereof: -AlN,AlMeN, -AlScN,AlScMeN, -AlCrN or -MgHfN,MgHfMeN, Me represents at least one additional metal whose concentration is 0.1 to 10 atomic percent relative to the total metal content of the corresponding layer.

35. The method according to claim 32 or 33, characterized in that The first voltage source is a first RF-source driven at a frequency of 2 to 30 MHz, 0 to 100 W.

36. The method according to claim 32 or 33, characterized in that The second voltage source is a pulsed DC-source driven at a pulse frequency of 50 to 400 kHz.

37. The method according to claim 32 or 33, characterized in that The second voltage source comprises a DC-source and a second RF-source connected to each other via an adapter network, whereby the target electrode is driven at a pulse frequency of 0.9 to 30 MHz.

38. The method according to claim 32 or 33, characterized in that The film stress, rocking curve, full width at half maximum, loss angle delta, or surface roughness of a substrate coated with a sputter-deposited layer is optimized by at least one of the following process parameters: - the power of the first voltage source; - the power of the second voltage source; - in case the second voltage source is a DC-source combined with a second RF-source, the quotient of the powers of said DC-source and said second RF-source; - in case the second voltage source is a pulsed DC-source, the duty cycle of said pulsed DC-source; - the distance between the substrate surface and the target surface; - a defined voltage applied to the isolated ring shield; - high deposition temperature of the piezoelectric coating; - an annealing step of annealing at least the seed layer and / or the metal layer.

39. The method according to claim 38, characterized in that It includes the following steps: - providing a flat substrate into a sputtering compartment (18) of a vacuum processing chamber (11); - etching a surface of the substrate by physical vapor etching (PVE); - depositing a first metal layer (Me1) on the etched substrate surface by sputtering in a first metal deposition step; - In the annealing step, the temperature of the compound deposition is higher than the temperature T of the subsequent compound deposition step. COMP At least 50°C higher annealing temperature T A annealing the metal layer (Me1); - in a first compound deposition step, by reactive sputtering, on the outer surface of the metal layer (Me1) at a temperature T COMP Depositing a first compound layer (Comp1) below; - depositing a second metal layer (Me2) on the outer surface of the first compound layer by sputtering in a second metal deposition step.

40. The method according to claim 39, characterized in that A seed layer is provided between the physical vapor etching step and the first metal deposition step by metal or reactive sputtering.

41. The method according to claim 39 or 40, characterized in that The annealing step is applied in a separate annealing furnace.

42. The method according to claim 32 or 33, characterized in that Further processing steps are applied in separate processing systems.

43. The method according to claim 42, characterized in that The further processing step comprises a structuring step of the metal layer (Me1) before depositing the compound layer (Comp1).

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