Vacuum system and method to deposit compound layer

Abstract

To provide an apparatus and a multi-chamber system (MCS) to enable the deposition of piezoelectric layers and coatings, as well as the production of respectively coated substrates, such as wafers.SOLUTION: A vacuum apparatus to deposit a compound layer on at least one plate-shaped substrate by sputtering is provided. The vacuum apparatus comprises a vacuum chamber (11) having side walls around a central axis (A), wherein the vacuum chamber (11) includes a pump compartment (17) connected to a bottom (20) of a sputter compartment by a flow path, wherein the flow path is designed to provide essentially the same flow conductance in an upper position and a lower position of a pedestal and at any position between the upper position and the lower position. The vacuum apparatus further comprises a vacuum pump system (16) connected to the pump compartment (17).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present application relates to a vacuum apparatus for sputter deposition of a compound layer according to claim 1, a multi-chamber system (MCS) according to claim 25, and a method for manufacturing an essentially two-dimensional flat substrate in a coated state according to claim 32.

Background Art

[0002] Since the miniaturization of piezoelectric devices such as microphones, electrical frequency filters, ultrasonic generators, sensors and actuators is still in progress, the material properties of piezoelectric materials, particularly those of piezoelectric layers and coatings, are becoming increasingly important. Such properties are represented by a uniform and highly oriented fine structure, as shown by the θ / 2θ X-ray diffraction pattern and represented by a narrow FWHM value of the rocking curve, and low dielectric loss properties such as a low tanδ value. It is well known that the piezoelectric response can be improved by alloying a piezoelectric AlN film with other metals, whereby the hexagonal structure of AlN is still preserved. The most promising material for industrial use is Sc with a Sc concentration of up to 43 at%. Other known materials are Cr and MgHf. However, it has been found that the quality of such coatings in mass production depends on the very strict reproducibility of layer parameters directly related to the requirements of each device and system and strict process control. Despite many efforts and advances in current state-of-the-art vacuum equipment, no appropriate technical provisions have been established so far to address all the problems necessary to meet the rapidly increasing demand for the high precision and performance required for manufacturing coatings for such devices.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The object of the present invention is to provide an apparatus and a multi-chamber system (MCS) that enable the deposition of piezoelectric layers and coatings, and the production of coated substrates such as wafers, thereby providing better process control. Such process control can include a better vacuum regime with respect to minimized pressure fluctuations during the deposition of the piezoelectric layer and 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 background art, it should be noted that the present invention is directed towards improving such state-of-the-art materials, regardless of the fact that the examples and embodiments of the present invention can be discussed with respect to some materials for reasons of practicality.

Means for Solving the Problems

[0004] The vacuum apparatus of the invention can be used for very different types of layers, but essentially has some design features that improve the stability and reproducibility of the process when depositing a compound layer on at least one plate-shaped substrate by sputtering. Such features are a vacuum chamber with sidewalls around a central axis (A), - at least one inlet for process gas, - at least one inlet for inert gas, - a substrate handling opening, - a pedestal including an electrostatic chuck formed as a substrate support in the central lower region of the sputtering section, the pedestal being mounted in an electrically insulated manner and connected to a first pole of a first voltage source by a switch controlled, for example, by a system control unit of the apparatus, whereby a bias electrode is formed together with the electrostatic chuck (ESC), and when the sputtering process is active, the pedestal is vertically movable from an upper processing position to a lower processing position and from the lower processing position to the upper processing position towards and away from the target, thereby enabling control of the film stress on the substrate beyond the life of the target and compensating for the ongoing target erosion, a pedestal, - A magnetron sputtering source, the magnetron sputtering source includes, on the front facing the sputtering compartment, for example, a target of metal or alloy, and includes a magnetic system on the back of the sputtering source. The magnetron sputtering source can additionally include a cooling backplate and / or, for example, a water-cooled flange between the target material and the magnetic system. The target is attached in an electrically insulated manner to a central region in the top region of the sputtering compartment of the chamber, and is connected to the first pole of a second voltage source by, for example, a further electrical switch controlled by the system control unit of the device, thereby forming the sputtering surface of the sputtering electrode, a magnetron sputtering source, - An essentially cylindrical anode that forms a ring around the target and at least around the upper part of the pedestal including the substrate support and the ESC, thereby forming the side wall of the sputtering compartment, and is electrically connected to ground, an anode, - A pump compartment that is connected to the bottom of the sputtering compartment by a flow labyrinth to prevent so-called "plasma spill out" from the sputtering compartment into the pump compartment. Thereby, together with well-known drawbacks such as process instability, parasitic losses of plasma output, and potential damage to the pump equipment, plasma enters the pump compartment. The flow path is designed to provide essentially the same flow conductance at the upper position and the lower position of the pedestal and at any position between the upper position and the lower position, a pump compartment, A chamber including, A vacuum pump system (16) connected to the pump compartment (17), Including.

[0005] The movement of the pedestal during the execution of the sputtering process can be carried out by a stepping motor or other positioning means controlled by the system control unit, as is known to those skilled in the art.

[0006] One design for achieving such characteristics of the flow path could be to provide a flow path having the same flow area during movement from an upper position to a lower position. In a further embodiment, the flow path can include at least one annular pump channel that loops around the pedestal in the region below the substrate support and the ESC. Thereby, at least one characteristic distance (w ch ) between at least two cylindrical and / or ring-shaped peripheral walls of the pump channel can be kept constant at the upper and lower processing positions of the pedestal and at any position between the upper and lower processing positions. Such characteristics of the flow path can be combined with all embodiments of the present invention.

[0007] In a further modification, the device can have an electrically insulated target ring that is mounted in a loop around the target between the target and the anode. The target ring can be made of a conductive material, such as metal, alloy or carbon, and is insulated from the ground and the target potential by at least one isolator that is hidden, for example, by the anode and / or the target shield from any line of sight towards the sputtering compartment. At the same time, the dark space distances between adjacent conductive components such as the target and the target ring, and the target ring and the anode are observed, which can be between about 2 mm and 10 mm at the normal process pressure between 0.1 Pa and 13.3 Pa (1 mTorr to 100 mTorr) used in the sputtering process. Thereby, the formation of a floating potential on the target ring can be guaranteed for a long time during the sputtering process without the need to replace the isolator for the formation of a conductive surface area. At least one, for example at least partially ring-shaped, isolator can be arranged on the anode or in the channel structure of the anode and can include a ceramic material such as alumina, boron nitride, etc.

[0008] In a further embodiment, a ring-shaped ring shield is electrically insulated and mounted on the pedestal, surrounding the substrate support, the wafer mounted on the support and optionally the ESC. The ring shield of the device of the present invention can be connected to a third voltage source that adjusts the voltage according to the requirements of the process, which can be used as an additional variable that affects the film stress of the sputtered layer.

[0009] The ESC surface and / or the pedestal surface can include open structures with a depth of several micrometers or even sub-micrometers, each connected to at least one respective back gas inlet. When both surfaces include open structures connected to back gas inlets, a heat transfer inert gas such as Ar can be applied between the ESC surface and the mounting substrate to control the substrate temperature, and between the pedestal surface and the ESC to control the ESC temperature. This allows both at least one back gas inlet to be connected to a common, or, when different back gas pressures are to be used, to respective separate feed-throughs. This connects a common or respective separate gas supply for the cooling / heating gas to the common or separate feed-throughs to control the temperature of the substrate and / or the pedestal. The open structure can be a so-called mensa-structure with a number of support points evenly spread on each surface, such as a table, or a channel structure on the surface of the ESC and / or the pedestal, such as a spider web or a maze. For example, both structures can be applied to the surface by laser structuring of the surface. With separate pressure supplies and feed-throughs, a higher back gas pressure can be selected between the pedestal and the ESC, thereby enabling faster heat exchange.

[0010] To deposit a piezoelectric compound, the target can include at least one metallic element such as Al for depositing AlN or Al and Sc for depositing AlScN, Al and Cr for depositing AlCrN, or at least two metallic elements such as Al, Mg, and Hf for depositing AlMgHfN. The process gas will include nitrogen as a reactive gas. The target can be an alloy target or a powder metallurgically pore - tightly sintered target. Pore - tightly sintered means a target with a density close to the theoretical density, which can be achieved, for example, by spark plasma sintering.

[0011] The anode can be manufactured as a one - piece anode to enable uniform heat flow in the anode. Additionally, a heating / cooling circuit connected to a heating / cooling unit can be foreseen with the anode to anneal the anode during pump or idle times and cool the anode during the sputtering process. Further, gas supply means can be attached along the upper or lower periphery of the anode, or around the upper or lower periphery. Such gas supply means can include at least one of a gas ring with distribution openings assigned along its inner, outer, upper, or lower periphery, and a channel structure integrated into the anode with a circular distribution gap or assigned inlet openings and / or additional inlet channels respectively. The channel structure can be foreseen near the top of the anode around the target, thereby forming a channel either in the anode itself or between the anode and a floating target ring that may be located in the channel.

[0012] The first voltage source can be a first RF power source that can be driven between 2 MHz and 30 MHz, and in many cases, a power source of 13.56 MHz will be sufficient.

[0013] The second voltage source can be a pulsed DC power source or a DC power source combined with a second RF power source. When the DC power source is combined with the second RF power source, at least the DC power source is connected to the sputtering electrode by an adapter network, such as a low-pass filter, to protect it against harmful input RF. To adjust the phase relationship between the first RF source and the pulsed DC power source or the second RF source, the apparatus can include adjustment means. This can be realized by an adjustment unit integrated in the system control unit (SPU) or as 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 needs of the process. The pulsed DC power source can be driven in a frequency range from 50 kHz to 400 kHz with a duty cycle of 50% to 90% and a power of 7 kW to 14 kW.

[0014] Furthermore, the apparatus can include control means for controlling the flow of the reactive gas depending on at least one of the process parameters of the target voltage, the characteristic parameters of the plasma emission from the active sputtering surface of the target, and the gas composition. The characteristic parameters of the plasma emission can 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 can be measured by a process gas analysis system such as an RGA.

[0015] To avoid parasitic plasma around at least one of the ESC, the pedestal, and the RF feeding part of the pedestal base, a grounded dark space shield can be provided in a ring around at least the base of the pedestal at the dark space distance (see above). Such a dark space shield can form one side wall of the pump channel and can move with the pedestal. The second, outer side wall, with respect to the central axis A, forming such an annular pump channel can be formed by a second channel shield that is attached to and movable with the dark space shield or attached to or part of the fixed anode.

[0016] In addition, at least one of a pedestal temperature and a substrate temperature measurement device should be provided to control, for example, the pedestal temperature with an electrical temperature measurement device and / or the substrate temperature with an optical measurement device such as a pyrometer on the back surface of the substrate. Such temperature measurement devices are used to control the substrate temperature, for example, via a heating and cooling unit connected to each of the heating and cooling fluid circuits below the SPU and the supporting surfaces of the pedestal and / or ESC. It should be mentioned that in a standard process, one heating and cooling unit supplied to the pedestal, anode, and magnetron sputtering source to temper or cool the backplate or target flange may be sufficient. However, in processes requiring more precise temperature control, separate heating and cooling units for the pedestal and separate cooling / tempering units for the magnetron source and anode would be more suitable. This has proven that precise temperature control of the pedestal and thus the substrate is one key to generating a highly textured compound layer. For example, at deposition temperatures higher than 100 °C, a resistive heater plate can be integrated in addition to or instead of the heating and cooling units on the surface of the pedestal.

[0017] In a further modification example, the target consists of - aluminum represented by Al or AlMe, - aluminum scandium represented by AlSc or AlScMe, - aluminum chromium represented by AlCr or AlCrMe, - magnesium hafnium represented by MgHf or MgHfMe, at least one of these materials or a mixture thereof, and AlSc, AlCr, or MgHf always contains at least 1% of the major metal at a lower concentration regardless of the presence of any further minor metal Me. Therefore, Me represents at least one further, for example, minor metal with a concentration of 0.1 atomic percent to 10 atomic percent based on the total metal content of each layer and the mixture of the two major metals.

[0018] The present invention also relates to a multi-chamber vacuum system (MCS) for processing at least one plate-shaped substrate, comprising at least one load lock chamber, transfer means, and at least three processing modules, whereby the first processing module can be a PVE module (P1) configured to etch the surface of the substrate, the second processing module can be a metal sputtering module (P2) configured to deposit a metal layer by sputtering on the surface of the substrate, and the third processing module can be a compound sputtering module (P4) configured according to the apparatus of the preceding claims.

[0019] The MCS system can also be a fourth process module, an annealing module (P3), configured to heat the substrate to an annealing temperature T between 550°C and 900°C, which can be configured to heat the substrate to its annealing temperature T within 60 seconds to 180 seconds. A The fourth process module can be included, which can be configured to heat the substrate to its annealing temperature T within 60 seconds to 180 seconds. A The fourth process module can be included, which can be configured to heat the substrate to its annealing temperature T within 60 seconds to 180 seconds.

[0020] In a further embodiment, the MCS system can also include at least one further one of a PVE module (P1'), a metal sputtering module (P2'), and a compound sputtering module (P4').

[0021] In any of such embodiments of the MCS, at least one load lock chamber and the process 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 the process modules (P1,... P4') can be arranged in a linear manner, and the handler can be a linear handler, for example, at least one transport belt or transport chain.

[0022] In such an embodiment of the MCS, the pre-treatment and post-treatment modules (pp12 , pp 34 , pp 56 at least one of ()) can be operably connected to at least one of the load lock chambers.

[0023] The present invention also includes a method of manufacturing a coated substantially two-dimensional flat substrate, such as a wafer, by a sputtering process, whereby an aluminum-containing target is sputtered in an apparatus as discussed above. Thereby, a piezoelectric AlN film is alloyed with at least one minor metal Me m to improve the piezoelectric response, whereby the hexagonal structure of AlN is still preserved. Me f can be at least one of Sc, Cr, Mg or Hf that can be alloyed to the sputtered aluminum target. Such a method can include the deposition of at least one piezoelectric layer. This layer is - aluminum nitride (AlN, AlMeN), - aluminum scandium nitride (AlScN, AlScMeN), - aluminum chromium nitride (AlCrN) or - magnesium hafnium nitride (MgHfN, MgHfMeN), and can consist of at least one of these materials or a mixture thereof, and Me represents at least one minor metal, for example, at a concentration of 0.1 atomic percent to 10 atomic percent based on the total metal content of each layer.

[0024] The first voltage source can be a first RF source connected to the bias electrode and driven at a frequency of 2 MHz to 30 MHz with a very gentle bias power of 0 W to 100 W or even lower 0 W to 30 W to avoid preventing the growth of each piezoelectric layer. On the other hand, the second voltage source can be a pulsed DC source connected to the target electrode and driven with a power of 7 kW to 14 kW and a pulse frequency of 50 kHz to 400 kHz. Furthermore, a positive voltage can be applied during the off period.

[0025] Alternatively, the second voltage source can include a DC source, a second RF source, and a target electrode connected to each other by an adapter network, whereby the second RF source can be driven at a pulse frequency from 0.9 MHz to 30 MHz.

[0026] To optimize some of the characteristics of the layer, this can be to minimize and / or equalize as much as possible the stress and / or stress distribution of the coating on the wafer surface, respectively, of the sputter deposition layer, e.g., over a series of processes that depend on subsequent thickness or stress measurements and / or during the process by in-situ process control, e.g., depending on optical film thickness measurement or respective in-situ stress measurement, - The power of the first voltage source, - The power of the second voltage source, - The duty cycle of the pulsed DC source, - The quotient of the power of the DC source and the second RF source, - The distance between the substrate surface and the target surface, which can also be effectively used to balance the influence of target erosion over several process cycles, - The defined (DC, RF) voltage applied to the insulating ring shield, - The high deposition temperature of the piezoelectric layer, - An annealing step to anneal at least the seed and / or bottom layer, at least one of the process parameters can be changed stepwise or continuously.

[0027] Furthermore, the characteristics of the layers or coatings merely mentioned by way of example can be adjusted by the above process parameters, e.g., as the rocking curve of the wafer, which can be measured by diffraction topography methods such as plane wave topography, in particular each successive topography along the rocking curve. A good approximation that can be used instead is the determination of the full width at half maximum (FWHM) of some characteristic crystal lines of each measured X-ray diffraction pattern.

[0028] The same refers to the dielectric loss that can be quantified as the contribution of the surface roughness of the coated layer and the layer-specific dissipation of electromagnetic energy and given as the loss angle δ or the corresponding loss tan δ. Examples are given below.

[0029] Examples and Figures Here, the present invention will be further illustrated using examples and figures. All of these figures are merely schematically and simplifiedly drawn, and the same reference signs refer to the same or similar functional features. When referring to terms such as top or bottom, up, upward, downward and upward or left and right, such terms are used in a non-limiting way for ease of use or only with reference to the figures, and thus if the same inventive concept is to be applied to another type of device having both a target and a substrate in a vertical or inclined position, it should be mentioned that the top and bottom configurations where the wafer and the target are in a horizontal position opposite to the current one can also be applied to, for example, the left and right configurations, or vice versa. The same refers to the cylindrical and ring-shaped structures resulting from each design of the examples shown that can also be transferred to other chamber symmetries, for example, (straight) angular shapes.

Brief Description of the Drawings

[0030]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiment for Carrying Out the Invention

[0031] FIG. 1 shows an overview of a sputtering apparatus of the invention including a two-part vacuum chamber 10 divided into a sputtering section 18 and a pump section 17 both connected with respect to the gas flow by a flow path 26. In this embodiment, the apparatus has an essentially cylindrical setup around the apparatus axis A. The target diameter r t and the inner diameter r a of the anode 2 forming the side wall of the sputtering section 18 can be selected according to the substrate, for example according to the wafer size. For a 200 mm wafer, the target diameter r t can be selected from 250 mm to 400 mm, and the inner diameter r aIt can be selected from 300 mm to 450 mm. The side wall 11 is designed as the anode 2 of the magnetron sputtering source 22 at the top of the sputtering section 18, which includes the target 1 and the magnet system 23. Further, a target backplate 24 can be provided in the case of expensive or mechanically weak target materials. An insulated but conductive target ring 3 is disposed on a ceramic isolator 43 in the form of a ring or ceramic support disposed around the upper periphery of the anode 2 around the target 1 between the target 1 and the anode 2. The target ring 3 is at a floating potential. The isolator 43, together with the inlet gap 35, is hidden from any line of sight towards the sputtering section 18 in a channel structure 34 that provides an inlet 13 for a process gas that can be a mixture of different reactive gases with or without the addition of a reactive gas, diluent inert gas. In the embodiment shown in FIG. 1, the inlet gap 35 is formed between the anode and the target ring 3. An alternative or additional inlet for the process gas can be provided in the form of a gas ring 33 near the lower periphery of the anode. This allows the supply of the process gas and the inert gas to be split, which, for example, can help prevent poisoning of the target when the process gas is supplied only via a remote gas ring 33 that can be arranged in the pump section 17 as shown, and only the inert sputtering gas is provided at the upper inlet 13.

[0032] At the bottom of the sputtering section 18, a vertically movable RF pedestal (refer to reference numerals 5 and the vertical double arrow) is attached, including an electrostatic chuck 6 for fixing the wafer 4 and the pedestal base 5'. The ring shield 7 and the dark space shield 8 can be moved up and down together with the pedestal. Both the ring shield 7 and the dark space shield 8 are electrically insulated with respect to the RF potential of the pedestal and / or at the dark space distance to each RF support portion of the pedestal 5 and the pedestal base 5'. However, while the dark space shield 8 is at ground potential, 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 section 18. Such a third electrode 7 surrounding the wafer can be used in addition to other known measured values, such as the target power and the substrate bias, to optimize the stress and stress distribution within the layer of the piezoelectrically active coating. Through respective feedthroughs 32, the pedestal is connected to the RF line 41 and the fluid line 42 for heating and cooling the pedestal 5 and the ESC 6. An optical temperature measurement device 40, such as a pyrometer, is used to control the temperature on the back side of the wafer 4, which requires an additional optical feedthrough 32. A pump socket connected to the high vacuum pump system 16 is provided at the bottom or the side wall 11 of the exhaust section 17.

[0033] Figures 2 to 5 show different modification examples of the flow path 26. While all components connected to the pedestal 5 or its base 5', such as the electrically insulated ring shield 7 and the dark space shield 8, move with the pedestal, the anode 2 and the channel shield 9 are stationary. For reasons of process stability, it is important to keep pressure fluctuations as low as possible. Therefore, it is important to provide the same pump speed at all process-related positions of the pedestal, which does not necessarily include potential load and unload positions, such as the possible lowest position or alternatively the highest position. The typical process-related movement of the pedestal over the entire target life can range from 40 mm to 90 mm for thick targets, and for a normal 6 mm target the movement is about 15 mm to 40 mm, so a movement of 15 mm to 90 mm would be sufficient for all requirements. All types of the flow path 26 include at least one annular pump channel 27.

[0034] During movement, the characteristic distance (w ch ), for example, the characteristic width of the channel in the flow path that defines the minimum flow area, does not change and it is important to keep it constant. To illustrate the situation with a simple flow path between the sputtering section 18 and the pump section 17, several distances I, II, III, IV that can be characteristic distances during a certain movement distance of the pedestal are shown in FIG. 5. In this example, the pedestal has an overall stroke of 95 mm and is designed for a process-related movement of 40 mm (from 65 mm to 95 mm, the possible highest position of the pedestal). Refer to the figure in FIG. 6 under certain vacuum and evacuation conditions defined by the cross-section of 110 cm ai between the inner circumference r 2 of the lowest part of the dark space shield 8 and the anode shield 2. Within this range, the distance I is the characteristic distance w for the flow path chDefine and move the wafer towards and away from the target surface to compensate for target erosion and / or control the layer stress in each layer stack of the coating. As the movement value becomes lower, distance II becomes the characteristic value of flow path 26 as indicated by the thick dashed line in Feature Graph V. However, within this lower range, as distance II decreases when the pedestal fin approaches the inner peripheral surface at the bottom of the anode (dashed line), the flow area constantly decreases. At the end of the lower part of the movement (not shown in the figure), distance III becomes the characteristic value before the pedestal seats on the anode with zero mm of movement. From Figure 2 to Figure 5, the gas inlet 13 is integrated within the anode 2 instead of between the anode 2 and the target ring 3. However, it is also possible to use the same structure from Figure 2 to Figure 5, or conversely, to use the anode-integrated gas inlet in the embodiment of Figure 1. The horizontal dashed line in Figure 5 indicates an alternative higher position of the upper surface of the ring shield 7, which can have some advantages with some process parameters and can also be combined with any embodiment of the actual invention. This allows the upper surface of the ring shield to be flush with the chuck 6 or the substrate surface or any location therebetween.

[0035] Similar considerations can be made as shown in Figures 3 and 4 for flow path 26, both of which include one 180° turn each within the flow channel, and thus, any plasma spill-out from the sputtering section to the pumping section is very effectively prevented as long as the slit width at the inlet of the flow path conforms to the requirement of the dark space distance according to the respective vacuum conditions or is covered by a dimensioned grid. In Figure 3, the dark space shield 8 is formed in a trough shape, and the channel shield 9 is disposed at the center of the trough, both defining a U-shaped flow channel. In Figure 4, the channel is integrated with the channel shield 9, which here forms part of the anode 2. These are related to the anode radius r within the sputtering section a and, in this case, the lower anode radius r at the dark space distance to the dark space shield 8 aiis disposed between and. For example, the integration or complete flow path 26 of the portion of the flow path 26 within the anode shield 2 as an integral device or at least a closely thermally coupled, has advantages with respect to a more uniform temperature distribution within the sputtering compartment. In FIG. 4 the channel coming from the sputtering compartment 18 is split into two S-shaped curves laterally and enters into the exhaust compartment 17. In this case, the characteristic distance w ch =w ch1 +w ch2 where w ch1、2 can be defined as the width of each sub-channel with a curved flow arrow.

[0036] For a 30 liter capacity of the sputtering compartment as used in all types of flow paths, an exhaust speed of 500 l / s to 700 l / s should be adjustable. This corresponds to an exhaust speed of about 2000 l / s for a high vacuum pump system 16 connected to the pump socket 44 of the exhaust compartment 17, for example including a turbomolecular pump, due to the flow resistance of each flow path 26 used.

[0037] Figure 7 shows the details of the pedestal 5 of the invention having two inlets 16 for inert heating / cooling gas, namely one back gas inlet 30 for the wafer and one back gas inlet 31 for the ESC when fixed to the ESC. Each inlet channel 14 connects the gas inlet to the feed-through 32 at the bottom of the pedestal base 5'. Such a configuration can raise the back pressure for the ESC to a higher value thereby, while the back pressure for the wafer is very limited, for example, to a maximum of 5 sccm for a 200 mm wafer, and there are several advantages compared to a configuration with only one inlet for both systems to avoid arcing that would occur at a higher flow rate as only wafer 4 separates inlet 30 and channel 29 from the high vacuum of the sputtering compartment. With such a configuration, the ESC 6 can have a surface patterned by the open channel 29 with respect to the wafer to increase the flow resistance of the heating / cooling gas when flowing from inlet 31 under the wafer towards the outer region of the ESC 6, and the heating / cooling gas can escape into the high vacuum of the sputtering compartment (see upper horizontal arrow). The surface pattern can be of any type of flow path pattern, such as a spider web, spiral, meandering or mender-shaped pattern of the open channel 29, with the height of the passage being several μm or even lower, very low to keep the flow resistance high. This achieves an even gas distribution on the back side of the wafer as well as an even distribution of support points or regions for wafer support, and can avoid any mechanical stress due to the electrostatic force of the ESC 6. Due to the combination of a high support area providing a short path for gas molecules between the cold / warm ESC surface and the wafer and a uniformly spread shallow channel cavity, ultimately, for example, when combined separately with inlet 30 at different points on the ESC surface for a wafer size ≧ 200 mm, the cooling and heating on the back side of the wafer can be most efficiently performed even with a low back gas flow and pressure.

[0038] The inlet channel 14 from the feed-through 32 that cools / heats the lower side of the ESC to the back gas inlet 31 ends here at the open channel 28, which is realized here as the back gas chamber 28 between the pedestal and the ESC. From here, the back gas can flow out into the exhaust compartment 17 via the needle channel 48 and the base channel 49, as represented by the curved and lower horizontal arrows, both of which provide a high flow resistance to enable a higher back pressure between the pedestal 5 and the ESC 6, which can be from about 0.1 hPa to 1 hPa (10 -1 mbar ~ 10 0 mbar). Heating of the chuck 6 made of an insulating ceramic material and including at least one RF electrode 47 is provided by a heater plate 46 on the base 5' of the chuck. Alternatively, or in addition, a water-cooled chuck can be used.

[0039] Four process modules P1 to P4 and up to six pre- or post-treatment modules pp 12 from pp 56 are included, with the latter arranged in pairs above and below the wafer handling level. A multi-chamber system MCS50 is shown in Figure 8. All modules are arranged circularly or polygonally around a central handler section 51 that includes a freely programmable handler 52 that transfers wafers from the pre-treatment module to the process module, transfers wafers between modules, and finally returns the wafers to the post-treatment tool. Transfer in and out of the MCS is done by a load lock 53 for incoming wafers and a load lock 54 for outgoing wafers. At least one additional handler transfers wafers from a load lock chamber 55, which is realized here as one load lock section, to the pre-treatment module pp 12 and back again from the post-treatment module pp 56 to the load lock section. The pre- and post-treatment modules pp 12 、pp 34 、pp 56It can include at least one of a buffer for wafers waiting to be processed or transferred, a heating station, a cooling station, and an aligner station. A process module as current shows the minimum configuration when annealing is to be executed within the MCS. Thus, module P1 includes a PVE station, P2 includes a metal sputtering station, and P3 includes an annealing chamber with a flat carbon heater facing the substrate surface to be heated. The top and bottom of the annealing section include cooled reflective surfaces, whereby the substrate is held near its outer periphery by the support of three fingers. Finally, module P4 includes the compound sputtering apparatus 10 of the invention as described above. Additional modules, such as a second compound sputtering module that speeds up the overall process time by splitting the sputtering time for the thickest layer system of the coating in half, or a second metal sputtering module for a layer system including two or more metal electrodes, can be connected via the dock 56.

[0040] The system control unit 36 of the MCS can include the respective system units of the modules or at least control the timing of such units, and is controlled by a control means 38, an adjustment means 37, a measurement means 40, and a sensor (not shown), which can be at least partially included within the system control unit 36 or separate from each respective module to be controlled, to control the transfer of wafers within all modules and the details of the process. The input / output unit 39 enables the operator to modify a single process parameter and automatically load a new process.

[0041] In Figure 9, the MCS50' of the linear module arrangement is schematically shown. In this case, for all process steps, a separate module is provided between the load lock 53 for the incoming wafers and the load lock 54 for the outgoing wafers, and dedicated load lock chambers 55' and 55" can each include pre- and post-processing modules or be connected to such modules (see Figure 8). When the substrate is 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 the module P4' to deposit a thin compound layer as a seed layer, to which the first metal layer Me1 is attached in the module P2. An annealing step in the module P3 and a further PVE step in P1 follow to refine the metal surface, and a functional piezoelectric layer Comp1 is attached in the module P4 to the etched metal layer Me1 in a further compound sputtering step, and finally a layer stack with a second electrode is completed in the module P2' with the second deposition of the second metal layer Me2, after which the substrate is locked out of the vacuum via the load lock 54. Wafer transfer between modules and between the modules and the load lock chambers 55', 55" is carried out by the linear handler 52'.

Explanation of symbols

[0042] 1 Target, sputter electrode 2 Anode 3 Floating target ring 4 Wafer 5 RF pedestal 5' Base of the pedestal 6 Electrostatic chuck (ESC) 7 Ring shield 8 Dark space shield 9 Channel shield 10 Sputtering apparatus 11 Vacuum chamber 12 Side wall 13 Inlet process gas 14 Inlet channel inert heating / cooling gas 15 Substrate handling opening 16 Vacuum pump system 17 Pump compartment 18 Sputtering compartment 19 Top of sputtering compartment 20 Bottom of sputtering compartment 21 First voltage source 22 Magnetron sputtering source 23 Magnet system 24 Backplate 25 Second voltage source 26 Flow path 27 Annular pump channel 28 Open channel pedestal / ESC 29 Open channel ESC / wafer 30 Back gas inlet wafer 31 Back gas inlet ESC 32 Feedthrough 33 Gas ring, inlet process gas 34 Channel structure 35 Inlet gap 36 Central processing unit 37 Adjusting means 38 Control means 39 I / O device 40 Temperature measurement device 41 RF line 42 Heating and cooling line 43 Isolator 44 Pump socket 45 Pedestal fin 46 Heater plate 47 RF electrode 48 Needle channel cooling / heating 49 Base channel chuck heater 50 Multi-chamber system (MSC) 51 Handler compartment 52 Handler 53 Load lock in 54 Load lock out 55 Load lock section 56 Dock Me m Minor metal A (preferably minor) metal having a concentration of 0.1 atomic percent to 10 atomic percent of Me P1...P4 process modules pp 12 ...pp 56 Pre- or post-treatment module r t Target radius r a Anode radius r al Lower anode radius w ch Width of the pump channel

Claims

1. 1. A vacuum apparatus for depositing a compound layer on at least one plate-shaped substrate by sputtering, comprising: A vacuum chamber (11) having a sidewall around a central axis (A), 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) including an electrostatic chuck (6) formed as a substrate (4) support in the central lower region of the sputtering section (18), said pedestal (5) being mounted in an electrically insulating manner and connected to a first pole of a first voltage source (21), said pedestal (5) being furthermore vertically movable from an upper position to a lower position and from said lower position to said upper position towards and away from the target (1) when the sputtering process is active; a magnetron sputtering source (22) comprising the target (1) at its front side and a magnet system (23) at its rear side, the target (1) being attached in an electrically insulated manner in a central region at the top (19) of the sputtering section (18) of the vacuum chamber (11) and connected to a first pole of a second voltage source (25); an anode (2) looped around the target (1) and around at least the upper part of the pedestal (5) containing the substrate support and the ESC (6), thereby forming the side wall (12) of the sputtering section, the anode (2) being electrically connected to ground; a pump compartment (17) connected to the bottom (20) of the sputter compartment by a flow passage (26), said flow passage being designed to provide essentially the same flow conductance in the upper and lower positions of the pedestal as well as in any position between said upper and lower positions; a vacuum chamber including: a vacuum pumping system (16) connected to said pump compartment (17), wherein a dark space shield (8) connected to ground is provided at least in a dark space distance in a loop around a base (5') of said pedestal (5), said dark space shield (8) forming one side wall of said pumping channel and movable with said pedestal, and a second channel shield (9) forming an outer side wall with respect to said central axis (A) so as to form an annular pumping channel, said second channel shield being attached to said dark space shield (8) and movable with said dark space shield (8); A vacuum device comprising:

2. 2. The apparatus of claim 1, wherein the flow path is designed to have the same flow area during movement of the pedestal from the upper position to the lower position and at any position between the upper and lower positions.

3. 3. The apparatus of claim 1 or 2, wherein the flow path comprises at least one annular pumping channel (27) looping around the pedestal in the region below the substrate support and the ESC.

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

5. 5. Apparatus according to any one of claims 1 to 4, characterized in that an electrically insulating target ring (3) is mounted annularly around the target (1) between the target and the anode.

6. 6. The apparatus of claim 5, wherein the target ring is made of a conductive material and is insulated from ground and target potentials by at least one ceramic ring hidden from any line of sight toward the sputter section.

7. 7. Apparatus according to any one of claims 1 to 6, characterized in that a ring shield (7) is mounted on the pedestal in an electrically insulating manner surrounding the substrate support and the mounted substrate.

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

9. 9. Apparatus according to any one of claims 1 to 8, characterized in that at least one of the surface of the pedestal and the surface of the ESC comprises an open channel (28, 29) connected to a respective backgas inlet (30, 31).

10. 10. The apparatus of claim 9, wherein both surfaces include open channels with backgas inlets.

11. 11. Apparatus according to claim 10, characterized in that both backgas inlets are connected to one common or respective separate feedthrough (32) to a common or respective separate gas supply.

12. 12. The apparatus according to claim 1, wherein the target comprises at least one metallic element.

13. The apparatus of claim 12, wherein the target comprises at least two metallic elements.

14. 14. Apparatus according to claim 12 or 13, characterized in that the target is an alloy target or a powder metallurgical sintered target.

15. 15. The device according to claim 1, wherein the anode is manufactured as a monolithic anode.

16. 16. Apparatus according to any one of the preceding claims, characterised in that gas supply means are fitted along or around the upper or lower periphery of the anode.

17. 17. Apparatus according to claim 16, characterized in that the gas supply means comprises a gas ring (33) with distribution openings allocated along its periphery and at least one channel structure (34) integrated into the anode with a circular distribution gap (35) or respectively allocated distribution openings and / or further distribution channels.

18. 18. Apparatus according to any one of claims 1 to 17, characterized in that the first voltage source is a first RF power source.

19. 19. The apparatus according to any one of claims 1 to 18, characterized in that the second voltage source (25) is a pulsed DC power supply, or a DC power supply and a second RF power supply, whereby at least the DC power supply is connected to the sputter electrode by an adapter network.

20. 20. The apparatus of claim 19, further comprising an adjusting means (36) for adjusting a phase relationship between the first and second RF sources.

21. 21. Apparatus according to any one of claims 1 to 20, characterized in that it comprises control means (37) for controlling the flow of reactive gases in dependence on at least one of the process parameters: target voltage, intensity or line pattern of plasma emission measured at the active sputtering surface of the target, gas composition.

22. 22. Apparatus according to any one of the preceding claims, characterized in that at least one of a pedestal temperature or a substrate temperature measuring device (38) is provided.

23. The target is aluminium (Al or AlMe), aluminium scandium (AlSc or AlScMe), aluminium chromium (AlCr or AlCrMe), magnesium hafnium (AlMgHf or AlMgHfMe), or mixtures thereof, with AlSc, AlCr or AlMgHf always containing a main metal in a lower concentration of at least 1%, so that Me represents at least one further metal in a concentration of 0.1 atomic percent to 10 atomic percent, based on the overall metal content of the respective layer and of the mixture of two or three main metals.

24. A multi-chamber vacuum system (MCS) for processing at least one plate-shaped substrate, comprising at least one load lock chamber, a transport means (52) and at least three processing modules, wherein a first processing module is a PVE module (P1) configured to etch a surface of the substrate, a second processing module is a metal sputter module (P2) configured to deposit a metal layer by sputtering on the surface of the substrate, and a third processing module is a compound sputter module (P4) configured according to the apparatus described in any one of claims 1 to 23.

25. Annealing temperature T between 550° C. and 900° C. Ａ 25. The MCS system of claim 24, further comprising a fourth process module that is an annealing module (P3) configured to heat the substrate to a temperature of 1000.degree.

26. The annealing module anneals the sample to the annealing temperature T Ａ 25. The MCS system of claim 24, configured to heat the substrate to

27. 27. The MCS system according to any one of claims 24 to 26, characterized in that it comprises at least a further one of at least one of a PVE module (P1'), a metal sputter module (P2') and a compound sputter module (P4').

28. 28. MCS system according to any one of claims 24 to 27, characterized in that the load lock chambers (55) and process modules (P1, ... P4') are arranged in a circular or polygonal manner around a central handler chamber (51).

29. The MCS system according to any one of claims 24 to 28, characterized in that the load lock chambers (55', 55") and the process modules (P1, ... P4') are arranged in a linear manner, and said handler is a linear handler (e.g. at least one transport belt or transport chain).

30. Pre-processing and post-processing modules (pp １２ ,pp. ３４ ,pp. ５６ 30. The MCS system according to claim 24, wherein at least one of said load lock chambers (55, 55', 55") is operatively connected to at least one of said load lock chambers (55, 55', 55").

31. A method for producing a piezoelectric coating on at least one side of at least one plate-shaped substrate (4), comprising a sputtering process carried out on an apparatus or MCS according to any one of claims 1 to 30.

32. At least one minor metal ｍ 32. A method according to claim 31, characterised in that the or each piezoelectric AlN film is deposited containing and / or scandium, whereby the hexagonal structure of the AlN is preserved.

33. The layer is aluminium nitride (AlN, AlMeN), - aluminium scandium nitride (AlScN, AlScMeN), Aluminum Chromium Nitride (AlCrN) or Magnesium hafnium nitride (MgHfN, MgHfMeN), or a mixture thereof, and Me represents at least one further metal in a concentration of 0.1 atomic percent to 10 atomic percent, based on the overall metal content of the respective layer.

34. 34. A method according to any one of claims 31 to 33, characterized in that the first voltage source is a first RF source driven at a power of 0 to 100 W and at a frequency of 2 to 30 MHz.

35. 35. A method according to any one of claims 31 to 34, characterized in that the second voltage source is a pulsed DC source driven at a pulse frequency of 50 kHz to 400 kHz.

36. 36. The method of any one of claims 31 to 35, wherein the second voltage source comprises a DC source and a second RF source connected to each other by an adapter network, whereby the target electrode is driven at a pulse frequency of 0.9 MHz to 30 MHz.

37. the power of said first voltage source, the power of said second voltage source, the quotient of the power of said DC source and said second RF source, the duty cycle of the pulsed DC source; the distance between the substrate surface and the target surface, a defined (DC, RF) voltage applied to said insulating ring shield, a high deposition temperature of the piezoelectric layer, - an annealing step to anneal at least the seed and / or the metal (bottom) layer; 37. The method according to claim 31 , characterized in that at least one of the process parameters optimizes the film stress, the rocking curve, the full width at half maximum, the loss angle δ, or the surface roughness of the substrate coated with the sputter-deposited layer.

38. - providing a flat substrate in a sputter compartment (18) of a vacuum processing chamber (11); - etching one side of said substrate by physical vapor etching (PVE); - depositing a first metal layer (Me1) on said etched substrate surface by sputtering in a first metal deposition step; - compound deposition temperature T of the subsequent compound deposition step ＣＯＭＰ An annealing temperature T at least 50° C. higher than Ａ annealing the metal layer (Me1) in an annealing step at in a first compound deposition step, by reactive sputtering, on the outer surface of said metal layer (Me1) at a temperature T ＣＯＭＰ Depositing a first compound layer (Comp1) with - depositing a second metal layer (Me2) on the outer surface of said first compound layer by sputtering in a second metal deposition step; 38. The method of claim 37, comprising:

39. 39. The method of claim 38, characterized in that a seed layer (Seed) is provided by metal or reactive sputtering between the PVE step and the first metal deposition step.

40. 40. A method according to claim 38 or 39, characterized in that the annealing step is applied in a separate annealing oven.

41. 41. A method according to any one of claims 31 to 40, characterized in that further processing steps are applied in a separate processing system.

42. 42. Method according to claim 41, characterized in that the further processing steps comprise a structuring step of the metal layer (Me1) before the compound layer (Comp1) is deposited.

43. 24. The device according to any one of claims 1 to 23, characterized in that the dark space shield (8) is formed in the shape of a trough, in the centre of which a channel shield (9) is arranged, together defining a U-shaped flow channel.

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