Vacuum substrate holder with optimized vacuum seal

Abstract

A vacuum substrate holder (1) for clamping a substrate (13), comprising: a) a first vacuum zone (5,5',5'',5''') having at least one first clamping element (4,4',4'',4'''); b) a second vacuum zone (5,5',5'',5''') having at least one second clamping element (4,4',4'',4'''); and c) a vacuum zone (5,5',5'',5''') having at least one second vacuum zone (5,5',5'',5''') and at least one third vacuum zone (5,5',5'',5'''). a receiving ridge (9) disposed in the empty zone (5, 5', 5'', 5'''), wherein the receiving ridge (9) is disposed on a holding surface provided by the receiving ridge (9) when the substrate (13) is fixed; and d) at least one transition zone (6, 6', 6'', 6''', 6''') separating the first vacuum zone (5, 5', 5'', 5''') from the second vacuum zone (5, 5', 5'', 5'''). IV ,6 V ) and wherein the transition zone (6, 6', 6'', 6''', 6 IV ,6 V ) has at least one sealing structure (10, 10', 10'', 10''', 10 IV ,10 V )

Description

[Technical Field]

[0001] The present invention relates to a vacuum substrate holder with an optimized vacuum seal, an apparatus for bonding substrates, and a method for bonding substrates. This is a solution for a multi-zone substrate accommodation device for fusion bonding and hybrid bonding.

[0002] Recently, substrate receiving devices have become popular with joining systems for fusion bonding and hybrid bonding that have two or more predetermined vacuum zones for substrate fixation.

[0003] These vacuum zones are preferably subjected to different vacuum pressures, which results in different strengths of pressing of the substrate to the receiving device. Since the holding or pressing force of the substrate to the receiving device influences the course of the bonding wave and in particular the (mechanical) stresses introduced at the bonding interface during the bonding process, it is therefore possible to actively influence the bonding result, in particular the distortion of the substrate, by deliberate control of the vacuum pressure for the individual zones. In particular, reference is made to the vacuum zone possibilities from WO 2017 / 162272.

[0004] The abrupt transition from one vacuum zone to the other leads to locally sudden changes in stress due to the abrupt change in framework conditions for the bond wave, and thus to distortion in the bonded wafer pair.

[0005] In the prior art, two vacuum zones are separated using a vacuum seal. One solution to this problem would be to divide the vacuum transition into multiple zones and define stages to prevent abrupt vacuum transitions. However, this would lead to an extremely complex sample holder and associated drive control using pneumatics and electronics, which is economically unsatisfactory and mechanically difficult or impossible to implement. This is because the construction space is limited, making drilling a large number of feed holes in the substrate receiving device impossible or even more difficult. These difficulties are particularly exacerbated when manufacturing substrate receiving devices made of ceramics, such as silicon nitride or silicon carbide (SiSiC ceramics).

[0006] For several years now, in the semiconductor industry, substrates have been bonded to one another by so-called bonding processes, before which the substrates must be aligned as precisely as possible with respect to one another.

[0007] One of the biggest challenges in bonding occurs during the bonding process itself, i.e., during the initial bonding phase until the contact surfaces of the substrates are fully contacted. Here, the alignment of the two substrates with respect to each other can change significantly compared to the previous alignment. Although the substrates can be aligned very precisely with respect to each other by the alignment system, distortions of the substrates can occur during the bonding process itself. The alignment accuracy at a specific spot on the substrate can be the result of distortions, scaling errors, lens imperfections (enlargement or reduction errors), etc.

[0008] In particular, abrupt changes should be avoided, because abrupt distortions resulting from the bonding process are difficult to compensate for using compensation measures, such as post-bonding lithography. In contrast, gradual distortions can be more easily compensated for, or at least minimized. The finer the structures to be reproduced, the more the quality of the manufactured semiconductor components depends on the tolerances, especially distortions, of the components used.

[0009] In the prior art, there are several methods and systems that can attempt to influence the bonding process, such as for example EP 2 656 378 or WO 2014 / 191033.

[0010] The object of the present invention is to envisage an apparatus and a method for bonding two substrates, in which sudden changes in the framework conditions for the bonding wave are avoided, thereby increasing the bonding precision and achieving a reduction in the distortion induced by the bonding.

[0011] It is therefore an object of the present invention to at least partially eliminate, and in particular completely eliminate, the drawbacks cited in the prior art. In particular, it is an object of the present invention to provide an improved vacuum substrate holder, as well as an improved device and method for bonding. Furthermore, it is an object of the present invention to provide a vacuum substrate holder in which bonding accuracy is increased and bonding-induced distortion is reduced.

[0012] This problem is solved by the features of the parallel independent claims. Advantageous developments of the invention are defined in the dependent claims. All combinations of at least two features described in the description, claims and / or drawings are also included within the scope of the invention. In the stated numerical ranges, values ​​lying within the boundaries should also be applied as disclosed limits and may be claimed in any combination.

[0013] Therefore, the present invention relates to a vacuum substrate holder for fixing a substrate, the vacuum substrate holder comprising at least a first vacuum zone having at least one first fixing element, a second vacuum zone having at least one second fixing element, accommodating ridges arranged in the at least first vacuum zone and the at least second vacuum zone, wherein the accommodating ridges are arranged on accommodating surfaces provided by the accommodating ridges when the substrate is fixed, and at least one transition zone separating the first vacuum zone and the second vacuum zone from each other, wherein the transition zone has at least one sealing structure, wherein when fixed, the first vacuum zone and the second vacuum zone are fluidly connected to each other by the transition zone.

[0014] In other words, a vacuum substrate holder is provided that provides a receiving surface for a substrate or substrate stack and that, by means of deliberately configured fluid communication in the transition zones, can achieve a gradual vacuum transition between adjacent vacuum zones, whereby a second zone can also be formed by the periphery of the vacuum substrate holder, thereby providing correspondingly advantageous pressure compensation at the periphery.

[0015] The receiving ridges are protruding protrusions, particularly of the same height, which are preferably regularly distributed in each zone over the entire vacuum substrate holder. These vacuum zones or the first and second vacuum zones are separated from one another here by transition zones. This transition zone is particularly advantageous in that at least one sealing structure separating the individual vacuum zones from one another is arranged inside this sealing structure, and in this example, unlike the prior art, fluid communication between the vacuum zones is provided by the transition zone.

[0016] When the substrate is placed on the receiving ridge or fastened to the receiving surface, the vacuum zones are in fluid communication only via the transition zone, whereby the substrate, the substrate holder, and the transition zone of the substrate holder form a vacuum zone, where the transition zone is designed to allow further fastening by a fastening element, thereby advantageously ensuring a gradual vacuum transition between the vacuum zones without limiting the function of the vacuum substrate holder.

[0017] The at least one fixing element is, in particular, one or more vacuum openings connected to a correspondingly controlled vacuum control unit. The at least one fixing element or elements can advantageously be used to fix the substrate in the respective vacuum zone. The sealing structure, which can be, for example, a sealing ring, is formed along the entire transition zone. As is customary for vacuum substrate holders, a radially symmetrical arrangement of the elements is preferred, in which case the transition zone is also preferably formed in the shape of a circular arc.

[0018] The transition zone advantageously prevents sudden changes in the vacuum value. Furthermore, good bonding results can be achieved with the vacuum substrate holder.

[0019] In a preferred embodiment of the vacuum substrate holder, it is assumed that at least one sealing structure has at least one opening, by means of which the flow cross-section of the sealing structure can be preset. Thus, the sealing structure has one or more desired openings to provide a specific flow cross-section through the transition zone, and thus from the first vacuum zone to the second vacuum zone. The design of the openings advantageously allows the flow characteristics to be set, and thus a gradual compensation can be achieved. In this case, the flow cross-section of the sealing structure preferably also represents the flow cross-section of the transition zone.

[0020] In a preferred embodiment of the vacuum substrate holder, it is envisaged that at least one transition zone each has at least two sealing structures, and that the at least one transition zone forms an intervening space between the most distant sealing structures of the at least one transition zone. In this particularly preferred embodiment, the transition zone preferably has at least two sealing structures directly abutting the respective vacuum zones. In this way, it is advantageously possible to separate the respective abutting vacuum zones along the entire radial extension of the transition zone. Furthermore, it is advantageously possible to provide an intervening space that allows for gradual pressure compensation between the first and second vacuum zones without causing joining errors due to abrupt changes in vacuum transition.

[0021] The intervening space can have further sealing structures between the two most distant sealing structures, which has a further positive effect on the joining result, since the vacuum transition can be carried out in more stages. In this case, the sealing structures in the same transition zone preferably have equal spacing from each other.

[0022] In a preferred embodiment of the vacuum substrate holder, it is assumed that the flow cross-sections of the two seal structures furthest from each other are identical. In this way, a particularly gradual vacuum transition is possible, since the openings or flow cross-sections of the seal structures located outside the transition zones are identical in design. Furthermore, the compensation can be performed uniformly in the direction of the first vacuum zone and the second vacuum zone. Preferably, all seal structures in the transition zone have the same flow cross-section. Advantageously, uniform compensation is guaranteed. Therefore, the flow cross-sections of all seal structures in at least one transition zone are identically sized or designed.

[0023] In a preferred embodiment of the vacuum substrate holder, the flow cross-section of the intervening space is assumed to be larger than the flow cross-section of the sealing structure in the transition zone. In other words, the intervening space forms a buffer, since compensation occurs only through the respective openings in the sealing structures, while at least one flow cross-section is provided within the transition zone that is larger than that of the sealing structure located on the outside. If three or more sealing structures or additional sealing structures are arranged between the sealing structures located on the outside, the flow cross-section of the intervening space is determined in the absence of the sealing structures. Thus, the volume provided by the intervening space between the sealing structures located on the outside advantageously provides space for compensating the vacuum. In this case, the volume and flow cross-section of the intervening space can advantageously be adapted by filling the intervening space with a material.

[0024] In a preferred embodiment of the vacuum substrate holder, it is envisaged that the flow cross-sectional area of ​​the intervening space is 5 times larger than the flow cross-sectional area of ​​the sealing structure of the transition zone, suitably 10 times larger, preferably 30 times larger, more preferably 50 times larger, even more preferably 100 times larger, most preferably 200 times larger, and most preferably more than 200 times larger in all.

[0025] In other words, the opening of the sealing structure is significantly smaller than the cross section of the intervening space.

[0026] In a preferred embodiment of the vacuum substrate holder, the at least one seal structure has a uniform height relative to the vacuum substrate holder surface, and the height of the at least one seal structure is smaller than the height (H) of the receiving ridge relative to the vacuum substrate holder surface, thereby forming a gap having a gap height (h) between the at least one seal structure and the substrate in the fixed state. In other words, the heights of the seal structures in the transition zone along the transition zone are uniform. Therefore, the gap between the substrate and the seal structure is also uniform. Therefore, the seal structure is recessed compared to the receiving surface provided by the receiving ridge. Therefore, a seal ring is provided for this embodiment. The vacuum seal can be recessed, for example, between 100 nm and 5 μm, preferably between 100 nm and 3 μm, and even more preferably between 100 nm and 500 nm. In comparison, the height H1 of the protrusion, which defines the height of the substrate mounting surface, is, for example, between 100 μm and 1000 μm. In this way, a gap of the same size is provided along the entire transition zone, ensuring a particularly uniform vacuum transition, in which case the above range has been found to be particularly suitable for application.

[0027] In a preferred embodiment of the vacuum substrate holder, the gap height is less than 10 times, preferably less than 30 times, preferably less than 50 times, even more preferably less than 80 times, most preferably less than 100 times, and most preferably less than 200 times the height of the receiving ridge. Here, the height of the receiving ridge is also determined by the vacuum substrate holder surface. In the clamped state of the substrate, this corresponds, in particular, to the distance between the substrate and the vacuum substrate holder surface. This gap thus also predetermines the flow cross-section of the respective abutting sealing structure. The aforementioned size ratios have been found to be particularly suitable for gradual vacuum transfer and therefore achieve very good joining results. The absolute height of the receiving ridge is less than 2000 μm, particularly less than 1000 μm, preferably less than 500 μm, more preferably less than 200 μm, and most preferably less than 100 μm.

[0028] In a preferred embodiment of the vacuum substrate holder, linear protrusions are arranged on at least one sealing structure at uniform axial intervals along the transition zone. The linear protrusions here preferably extend on the sealing structure along the entire transition zone. The linear protrusions are included in determining the height of the sealing structure. This allows for even more uniform compensation. Preferably, more than two, and even more preferably more than three, linear protrusions are arranged on the sealing structure at regular intervals from one another.

[0029] In this case, in one embodiment, the transition zone can be provided by a seal structure having a wide, linear protrusion, and preferably in this embodiment, the transition zone has only one seal structure.

[0030] In a preferred embodiment of the vacuum substrate holder, it is envisaged that at least one seal structure abuts at least partially against the substrate in a fixed state, and that an offset flow path is formed in the at least one seal structure along the transition zone.

[0031] Thus, the sealing structure or the sealing structure of the transition zone is not recessed and is in contact with the substrate. The flow passages are similar to the openings of the gap and can be formed arbitrarily. Preferably, the flow passages have a circular or rectangular cross section. In this case, the flow passages form the flow cross section. Particularly preferably, several, particularly preferably all, of the sealing structures of the transition zone have flow passages. These flow passages are preferably arranged on the surface of this or these sealing structures facing the substrate. Therefore, the substrate does not rest on the sealing structures in the area of ​​the flow passages. Particularly preferably, all of the sealing structures of a transition zone have flow passages that are preferably arranged regularly offset along the transition zone or along the radius, thereby widening the flow path. In this way, a particularly gradual vacuum transition and a particularly distortion-free joining result can be achieved.

[0032] In a preferred embodiment of the vacuum substrate holder, the spacing between the at least one first vacuum zone and the at least one second vacuum zone is less than 50 mm, preferably less than 25 mm, even more preferably less than 20 mm, most preferably less than 15 mm, and most preferably less than 10 mm in all cases. In other words, the transition zones are dimensioned accordingly. In the case of a circular vacuum substrate holder, the spacing is dimensioned radially, and in particular, transition zones formed as arcs have a radial extension corresponding to the above-mentioned values. A specific spacing between radially adjacent vacuum zones advantageously allows for a gradual transition at a typical substrate holder diameter. Furthermore, the flow cross-section of the intervening space can be provided over a predetermined region along the radial extension, thereby providing a minimum or maximum volume for the intervening space. It has been found here that the spacing between the vacuum zones is particularly suitable for achieving a gradual vacuum transition.

[0033] In a preferred embodiment of the vacuum substrate holder, at least one fixing element in a vacuum zone has at least one fluid opening, and all fluid openings in each vacuum zone together form the total flow area of ​​the vacuum zone. The flow cross-sectional area of ​​the sealing structure of the transition zone adjacent to each vacuum zone is 2 times smaller, preferably 5 times smaller, more preferably 10 times smaller, even more preferably 30 times smaller, most preferably 50 times smaller, and most preferably 100 times smaller than the total flow cross-sectional area of ​​the fixing element of the adjacent vacuum zone. The fixing element has one or more fluid openings for venting or exhausting each vacuum zone. The total flow cross-sectional area is predetermined by the total area of ​​all fluid openings of the fixing elements of the vacuum zone. In other words, the flow cross-sectional area of ​​the supply line of the transition zone is significantly larger than the flow cross-sectional area of ​​the sealing structure of the adjacent transition zone. In this way, a gradual vacuum transition can be advantageously set in relation to the parameters of the fixing elements.

[0034] In a preferred embodiment of the vacuum substrate holder, the cross-sectional flow area of ​​the sealing structure is less than 10 times, preferably less than 30 times, more preferably less than 50 times, even more preferably less than 80 times, most preferably less than 100 times, and most preferably less than 200 times, of the total opening area between the receiving ridges of the vacuum zone directly abutting the transition zone. In this case, the total opening area is preferably determined in a fixed state perpendicular to the substrate. The total opening area of ​​the vacuum zone toward the transition zone is predetermined by the free surfaces between the receiving ridges. In other words, the smallest area between the protrusions of each vacuum zone abutting the transition zone, i.e., the fluid flow path toward the transition zone, forms the total opening area. In this way, the vacuum substrate holder can be used to perform a particularly smooth and distortion-free joining process.

[0035] In a preferred embodiment of the vacuum substrate holder, it is assumed that the vacuum substrate holder has further vacuum zones, each of which is separated by a further transition zone, and that radially adjacent vacuum zones are fluidly connected to each other by the respective further transition zone. In other words, the vacuum zones can be connected in series or can be fluidly connected to each other. In this case, the transition zones are preferably arranged in the direction of the expected movement of the bonding wave. Radially adjacent vacuum zones are here each separated by a transition zone. In this embodiment, further features are also applicable in a technically significant manner, and in particular have the same advantages, further enhanced.

[0036] The present invention further relates to an apparatus for bonding substrates, comprising at least a vacuum substrate holder, which is intended for use in the bonding apparatus, and in particular the lower substrate holder, which is configured as a vacuum substrate holder and provides a step-by-step vacuum transition between the respective vacuum zones, thereby significantly improving the bonding accuracy.

[0037] Furthermore, the present invention relates to a method for bonding substrates, comprising, in particular in the following order, the following steps: i) providing a first substrate on a vacuum substrate holder, ii) providing a second substrate on the substrate holder, and iii) bonding the first substrate to the second substrate, wherein in particular a pressure difference in the respective vacuum zones of the vacuum substrate holder occurring during bonding in step iii) is compensated by at least one transition zone, in particular along the bonding wave progressing between the first and second substrates.

[0038] A particularly important aspect of the invention is that it allows for a gradual vacuum transition from one vacuum zone to the next in the region of the receiving surface of the receiving device or vacuum substrate holder, which allows for a reduction in bonding-induced distortion, since abrupt changes in the framework conditions for the bonding wave are avoided.

[0039] A gradual vacuum transition between two vacuum zones can be achieved by means of a deliberate structuring or transition zone: the introduction of a transition zone in the region of the transition zone with a larger flow cross section compared to the flow cross section in the region of the vacuum seal allows a gradual vacuum transition from one vacuum zone to the other.

[0040] These transition zones are particularly preferably not actively vacuumed and do not have any fixing elements.

[0041] The vacuum substrate holder allows for a controlled, gradual vacuum transition from one vacuum zone to the next. The transition zone between the two vacuum zones allows for a gradual vacuum transition from the first vacuum zone to the second vacuum zone, respectively. The change in substrate fixation from one vacuum zone to the other is implemented by a gradual vacuum transition generated by means of design optimization, which also gradually changes the framework conditions for the bonding wave. This reduces and homogenizes distortion, which leads to an increased quality of the bonded product.

[0042] Both substrates are fixed by a receiving device during bonding, in particular during the propagation of the bonding wave, preferably during fusion bonding and hybrid bonding.

[0043] An important aspect is that the substrates to be bonded are fixed on a holding device with multiple vacuum zones, which allow a gradual vacuum transition from one vacuum zone to the next on the holding surface of the holding device by using transition zones. This allows for a reduction in bonding-induced distortion, since uniform fixation avoids abrupt changes in the framework conditions for the bonding wave.

[0044] In a preferred embodiment, at least one of the two substrates is bent before contact connection or bonding, and the curvature of at least one of the two substrates is changed during bonding, particularly during the propagation of the bonding wave, by controlling the curvature. Changing the curvature particularly refers to a deviation from the initial state of the substrate. The curvature of at least one of the substrates is described in detail in WO 2017 / 162272. Therefore, a precise description thereof will not be provided herein.

[0045] In this case, the bonding is controlled, in particular by controlled control of the fixation of the substrate, in particular after contacting of the contacting surfaces.

[0046] In this case, between each two vacuum zones there is a transition zone without fastening elements, in which no vacuum is actively applied.

[0047] A further aspect of the invention resides in the use of, in particular, individually switchable fastening elements, which can be used to effect a controlled open-loop or closed-loop control of the bonding wave that advances between the contact connection surfaces.

[0048] A characteristic process in bonding, particularly permanent bonding, preferably fusion bonding, is the closest possible central and / or spot contact of the two contact-connecting surfaces of the substrates. In general, the contacting of the two substrates may not be centered.

[0049] By designing the fixation of the two substrates together with controlled open-loop or closed-loop control of the curvature and / or release of at least one of the two substrates, the advancing joining wave is controlled in such a way that an optimal, sequential and continuous contact connection of the two substrates along the contact connection surface is achieved, in particular from the inside to the outside.

[0050] An optimal contact connection means, in particular, that the local alignment errors ("runout" errors) at each point of the contact connection interface between the two substrates are minimal, or even disappear in the optimal case. Details of the different runout errors are given in WO 2014 / 191033, to which reference is made.

[0051] The present invention therefore relates in particular to a method and system that can be used to bond two substrates to one another, particularly in a way that minimizes bonding-induced distortions, since abrupt changes in the framework conditions for the bonding wave are avoided. Here, the substrates are particularly fastened by a plurality of fastening elements divided into vacuum zones. This allows for a gradual vacuum transition from one vacuum zone to the next on the holding surface of the receiving device. These transition zones are not supplied with vacuum and serve as intervening spaces between two different vacuum zones. The vacuum is generated in the intervening space or transition zone by leakage in the vacuum seal. In this case, the transition zone functions uniformly, since different leakage rates at different points along the vacuum seal are compensated for via the seals and / or structures in the transition zone. The gradual vacuum transition caused by the uniform substrate fastening from one vacuum zone to the other also results in a gradual change in the framework conditions for the bonding wave. This reduces and uniformizes distortions, which leads to an increased quality of the bonded product.

[0052] After the two substrates are contact-connected at their centers, the clamping means of the receiving device are actuated to, in particular, cause a controlled deformation / curvature change of at least one of the substrates. The upper substrate is pulled downwards in a controlled manner due to gravity on the one hand and the bonding forces acting between the two substrates along the bonding wave on the other hand. The upper substrate is thus bonded to the lower substrate in a radial direction from the center toward the lateral edges. This results in the formation of a radially symmetrical bonding wave extending in particular from the center toward the lateral edges. It is also conceivable that the upper substrate is held fixed during the entire time period of the bonding wave propagation, and that the progression of the bonding wave can proceed by gradually switching off the clamping elements, in particular starting from clamping elements in the substrate holders. The continuation of the bonding wave can also be promoted by the relative proximity of the two substrate holders to each other during the progression of the bonding wave.

[0053] The fixing element, according to an embodiment of the present invention, is a vacuum hole provided, one or more circular vacuum lips, or a comparable vacuum element that can be fixed with a wafer or substrate.

[0054] A pin in the central hole or conduit, through which a positive pressure can be created between the substrate holder and the substrate by introducing gas, is used for controllable bending of the clamped substrate (curvature means and / or curvature changing means).

[0055] These substrates can have any shape, but are preferably circular. The diameter of the substrates is particularly standardized in the industry. For wafers, the industry standard diameters are 1 inch, 2 inches, 3 inches, 4 inches, 5 inches, 6 inches, 8 inches, 12 inches, and 18 inches. However, individual embodiments can handle any substrate, essentially regardless of their diameter.

[0056] The bonding device or device for bonding has two receiving devices, one for the upper substrate and one for the lower substrate, which are generally not completely identical, since at least one of the receiving devices has one or more deformation elements that allow it to deform one of the substrates.

[0057] The receiving device for the upper and lower substrates has a fixing means, in particular a plurality of fixing elements, which may be grouped into vacuum zones. All fixing elements of one vacuum zone can be switched on and off simultaneously. Preferably, all fixing elements of a vacuum zone can be actuated by individual control elements, in particular control valves.

[0058] In a less preferred embodiment, all of the clamping elements in a zone can be individually switched, so that multiple clamping elements can be simultaneously actuated to clamp or release the substrate within the zone, or can be actuated individually, but still produce very individual deformation characteristics of the substrate within that vacuum zone.

[0059] The zones, or vacuum zones, may take, for example, the following geometric shapes, as are typical design specifications for zonal vacuum substrate holders: single-sided, circular segments, tiled, particularly triangular, rectangular, or hexagonal.

[0060] The fastening elements can in particular be electronically controllable. The fastening properties of the holding surface of the receiving device are controlled by the number of fastening elements per unit area and the respective set pressure.

[0061] In this case, vacuum clamping is the preferred clamping type. The clamping element can apply negative pressure for clamping. To release the substrate, the clamping element can also apply positive pressure.

[0062] In a first embodiment, the vacuum fixture comprises a plurality of vacuum paths extending from the substrate surface of the substrate holder, which are preferably individually controllable.

[0063] In a further embodiment, the fixing element comprises a plurality of holes.In a further embodiment, the fixing element is provided with an exhaust lip.

[0064] Several vacuum paths and / or holes are combined into individually controllable and therefore evacuable or ventable vacuum zones, but each vacuum zone is independent of the other vacuum zones, providing a means to create individually controllable vacuum zones.

[0065] The vacuum zone is preferably annularly structured, which allows for a targeted, radially symmetrical fixation and / or release of the substrate from the receiving device, in particular from the inside out. For the specifics of the vacuum zone, reference is made in particular to publication WO 2017 / 162272.

[0066] In a further embodiment, the vacuum zones are evenly distributed across the support surface.

[0067] In a further embodiment, the vacuum zone is present in an edge region of the holding surface of the receiving device, which edge region in particular extends up to half the radius, preferably up to one-quarter of the radius, of the holding surface of the receiving device.

[0068] Furthermore, the use of a receiving device with pin chucks (English: pin chuck) is disclosed. A pin chuck receiving device is understood to mean a receiving device whose surface is not flat but consists of a number of small raised portions or receiving ridges, or protrusions, that form a holding plane on which the substrate is supported. Details of this type of receiving device are described in the publications WO 2015 / 113641 and WO 2017 / 162272, which are also referred to herein. The use of this type of receiving device is advantageous in that it allows for as small a contact surface as possible between the substrate and the holding surface of the receiving device, thereby minimizing or even eliminating contamination on the back side of the substrate.

[0069] The height of the protrusions is in particular less than 1 mm, preferably less than 500 μm, more preferably less than 200 μm, and very preferably less than 100 μm.

[0070] In a preferred embodiment, the height of the protrusions is between 100 μm and 1000 μm.

[0071] The number of anchoring elements per vacuum zone is arbitrary, in particular there is at least one anchoring element in a vacuum zone, preferably at least two anchoring elements, preferably more than 10, more preferably more than 20, even more preferably more than 50, and most preferably more than 100 anchoring elements.

[0072] A plurality of successively arranged vacuum zones can be controlled, in particular activated or deactivated, thereby allowing for closed-loop control of the local clamping of the substrate, in particular the vacuum zones are activated with a preferably settable pressure that pre-sets the holding force of each of the zones by switching on all clamping elements within the vacuum zone.

[0073] One important aspect is that between the vacuum zones there are zones without fixation elements or without vacuum supplies, which are structured in such a way that a gradual vacuum transition is possible from one vacuum zone to the next at the holding surface of the containment device.

[0074] The spacing between two vacuum zones is in particular less than 50 mm, preferably less than 25 mm, even more preferably less than 20 mm, most preferably less than 15 mm, and most preferably less than 10 mm altogether. If the vacuum zones are formed as circular segments, the spacing will be the distance between the inner annulus of the outer circular segment and the outer annulus of the inner circular segment.

[0075] In addition to the mechanical stresses caused by the fixation of the substrate on the vacuum substrate holder (which may have already occurred in the substrate during pre-processing steps), the fixation of the substrate also generates new stress patterns. For example, asymmetric deformations occur when forces act on the substrate resting on structures on the holding surface. Forces acting on the substrate include, for example, gravity and suction forces of the individual vacuum zones. This asymmetric deformation also exists during the contact connection and / or bonding process between the two substrates, which inevitably leads to asymmetric expansion of the bonding wavefront and thus to undesirable runout effects, which are introduced into the bonding interface as distortions.

[0076] In this case, there are also surfaces or zones without fastening elements between the vacuum zones, which are designed or structured in such a way that a gradual vacuum transition from one vacuum zone to the next is possible on the holding surface of the receiving device, which allows for a reduction in distortion, since a sudden change in the framework conditions for the bonding wave is avoided.

[0077] In particular, abrupt changes in distortion are avoided by gradually changing the framework conditions for the bonding wave along different vacuum zones, rather than by abrupt changes. Abrupt changes should be avoided because abrupt distortions resulting after the bonding process are difficult to compensate for using compensation measures, such as post-bonding lithography. In contrast, gradual distortions can be easily partially minimized. The finer the structures to be reproduced, the more the quality of the manufactured semiconductor components depends on the tolerances, especially distortions, of the components used.

[0078] The gradual vacuum transition from one vacuum zone to the next is implemented by optimizing the design of the surfaces between the vacuum zones. The surfaces between the vacuum zones are surfaces without fixed elements, and no vacuum is actively applied to them. These surfaces between one vacuum zone and the next are called transition zones. The individual transition zones between different vacuum zones can be designed differently. Thus, there are at least two vacuum zones and at least one transition zone on the storage device.

[0079] The basic idea of ​​the present invention is to fabricate vacuum zone or sealing structures in the region of the vacuum seal between two vacuum zone or sealing structures on the holding surface of the storage device, which can ensure a gradual vacuum transition from one vacuum zone to the next. Advantageously, these structures are designed so that this gradual vacuum transition occurs uniformly all along the vacuum seal. These structures can be structures within the vacuum seal itself, such as flow channels, or vacuum seals that are set back, for example by changing dimensions, or structuring of intervening spaces in the region of the transition zone.

[0080] The transition zone may allow leakage gas to flow through more or less continuously, similar to a labyrinth seal or throttle gap seal.

[0081] A leak is an opening or gap in the enclosed space through which gas can escape (or enter in the case of a vacuum). The flow resistance depends, for example, on the gap height. An excessively small gap height means a very high flow resistance. Due to the recession of the vacuum seal, e.g. a ring seal, against the resting plane of the substrate on the holding surface of the receiving device, the flow cross section in the area of ​​the vacuum seal is determined by the gap height. This flow cross section in the area of ​​the vacuum seal is significantly smaller than the flow cross section in the area of ​​the resting surface, where the flow cross section is determined by the height of the protrusion.

[0082] In the prior art, no transition zone is incorporated between one vacuum zone and the next. Therefore, a vacuum seal exists between the two vacuum zones. By retracting the vacuum seal relative to the substrate placement surface on the holding surface of the receiving device, the flow resistance in the area of ​​the vacuum seal remains significantly greater than the flow resistance in the area of ​​the vacuum zone.

[0083] By introducing a transition zone with a large flow cross section compared to the flow cross section in the region of the vacuum zone, a gradual vacuum transition from one vacuum zone to the other becomes possible for the first time.

[0084] The gradual vacuum transition from one vacuum zone to the other is determined by the height of the vacuum seal between the two vacuum zones and by the choice of structures in the transition zone between them. By designing the transition zone and vacuum seal, the flow resistance in the area of ​​the vacuum seal, the area of ​​the transition zone, and the area of ​​the vacuum zone is controlled so that equalization occurs between the two vacuum zones in the transition zone, because the vacuum in the transition zone is compensated for by leaks in the vacuum seal or structures.

[0085] The recession of the vacuum seal relative to the substrate placement plane on the holding surface of the receiving device defines the gap height h that must be allowed for leakage. The vacuum seal can be recessed, for example, between 1 μm and 5 μm, preferably between 1 μm and 3 μm. In comparison, the height of the protrusion, which defines the height of the substrate placement plane, is, for example, between 100 μm and 1000 μm.

[0086] In one embodiment, two or more vacuum seals, in particular sealing rings, are installed between two vacuum zones. Here, no active vacuum is applied to the zone between the vacuum seals. The vacuum is generated in the intervening space by leakage in the vacuum seal. Here, the intervening space functions uniformly, since different leakage rates at different points along the vacuum seal are compensated for by the vacuum seal. This is particularly true when the flow cross-section in the region of the intervening space is larger than the leakage cross-section in the region of the individual vacuum seals. These cross-sections are preferably optimized for the best possible results. In particular, the gap height for the vacuum seals or structures is optimized. This leads to an optimized leakage in the region of the vacuum seals.

[0087] In a further embodiment, the height of the vacuum seal between the vacuum zone and the transition zone is recessed relative to the surface of the substrate support, in particular the surface of the protrusion. In this case, this distance (gap height) is selected to be significantly smaller than the height of the protrusion. The gap height is in particular less than 10 times, preferably less than 30 times, more preferably less than 50 times, even more preferably less than 80 times, most preferably less than 100 times, and most preferably less than 200 times, of the height of the protrusion. This ensures that the pressure drop is primarily in the area of ​​the vacuum seal, providing vacuum uniformity in the area of ​​the vacuum zone. A further important design criterion is that the leakage cross section should be significantly smaller than the cross section of the supply line. The leakage cross section is in particular 2 times smaller, preferably 5 times smaller, preferably 10 times smaller, more preferably 30 times smaller, even more preferably 50 times smaller, and most preferably 100 times smaller, and most preferably less than 100 times, of the cross section of the supply line. This ensures that the leakage is a defined resistance in the system and that the vacuum can be controlled open-loop to a desired and accurate value in the area of ​​the resting surface (holding surface).

[0088] In a further embodiment, the vacuum seal between the vacuum zone and the transition zone, or the vacuum seal present in the transition zone between two vacuum zones, is not recessed relative to the surface of the substrate support. Instead, a number of small channels are machined at regular intervals along the extension of the vacuum seal. In this case, the cross-section of these channels is selected to be significantly smaller than the cross-section in the region of the protrusion. The cross-section of the channels is in particular 10 times smaller, preferably 30 times smaller, more preferably 50 times smaller, even more preferably 80 times smaller, most preferably 100 times smaller, and most preferably 200 times smaller than the cross-section in the region of the protrusion. This ensures that the pressure drop is primarily in the region of the vacuum seal, providing vacuum uniformity in the region of the vacuum zone. In this embodiment, a further important design criterion is that the leakage cross-section should be significantly smaller than the cross-section of the supply line. The cross section of the leak is in particular 2 times smaller than the cross section of the supply line, preferably 5 times smaller, preferably 10 times smaller, more preferably 30 times smaller, even more preferably 50 times smaller, most preferably 100 times smaller, and most preferably all less than 100. This ensures that the leak is a defined resistance in the system and that the vacuum can be controlled open-loop to a desired and precise value in the area of ​​the support surface.

[0089] In a further embodiment, multiple vacuum seals are used in the transition zone, with additional vacuum seals positioned between the vacuum seals that define the transition between the vacuum zone and the transition zone. Thus, by positioning multiple (at least one) intervening vacuum seals, the vacuum transition between the two vacuum zones to which the vacuum is applied can be divided and staged into individual vacuum steps.

[0090] In a preferred embodiment, if the resistance of the individual vacuum seals is selected to be identical or the vacuum seals are manufactured identically, the individual intermediate steps of the vacuum value may be uniformly distributed.

[0091] In a further advantageous embodiment, the choice of the leakage cross section allows the vacuum stages to be divided in a deliberately non-linear manner, but to be selected according to the process requirements: the intervening spaces of the vacuum seals here serve to compensate, so that the vacuum gradient is as uniform as possible over the entire length of the vacuum seal.

[0092] In this case, the flow cross-sectional area of ​​the interstitial space should preferably be selected to be larger than the cross-section of the leak, in particular the interstitial space should have a cross-section that is 5 times larger than the leak, suitably 10 times larger, preferably 30 times larger, more preferably 50 times larger, even more preferably 100 times larger, most preferably 200 times larger, most preferably 200 times larger in all.

[0093] In a further embodiment, the transition zone between the two vacuum zones allows for short evacuation and venting times. In this particularly optimized embodiment, the leakage cross section (gap height) is selected to be as small as possible, which can then result in the cross section of the intervening space in the transition zone being similarly small. The small volume of the intervening space in the transition zone has the advantage in particular of allowing for faster evacuation and venting times of the containment device and therefore better output in dynamic use.

[0094] A further aspect of the invention is to select the spacing of the individual vacuum seals so that the vacuum gradient can be substantially obtained during the propagation of the bond wave. At low clamping pressures achieved by low vacuum values, the substrates are partially lifted from the receiving device in the region of the contact spot between the substrates during the propagation of the bond wave, which can lead to locally increased leakage in the region of the vacuum seals. This change in the local vacuum gradient in the transition zone is addressed by optimizing the spacing of multiple (up to n) vacuum seals in the transition zone.

[0095] The apparatus for bonding a first substrate surface of a first substrate and a second substrate surface of a second substrate includes a first receiving device for receiving the first substrate and a second receiving device for receiving the second substrate, wherein the holding surfaces of the receiving devices alternate between vacuum zones with fastening elements and transition zones without fastening elements and without a vacuum supply present therebetween.

[0096] The substrate holder may additionally have sensors that can measure physical and / or chemical properties between the clamped substrate and the receiving device and can be used in a control loop to control the clamping state, in particular the vacuum value.

[0097] Reference is made in particular to the devices described in publication WO 2017 / 162272. Further device features will therefore not be described in detail here.

[0098] Furthermore, a method for bonding a first substrate surface of a first substrate and a second substrate surface of a second substrate using the apparatus is provided, in particular reference to previously published method steps from publication WO 2017 / 162272.

[0099] In a first process step of a first process, a first substrate is loaded and secured in a first receiving device, and a second substrate is loaded and secured in a second receiving device.

[0100] In the second process step of the first process, these two substrates are aligned with each other. The alignment of the substrates is not described in detail here. In this respect, reference is made to the publications WO 2015 / 082020 and WO 2014 / 202106.

[0101] In the third process step of the first process, the two substrates are brought into proximity by moving the two substrate holders relative to each other.

[0102] In a fourth process step of the first process, bending of the first substrate and / or the second substrate is performed.

[0103] The fifth process step of the first process involves bonding the substrates after contacting at the bond initiation points and monitoring and controlling the bond wave.

[0104] The alignment and bonding within the alignment device and / or within the bonding device is preferably carried out at standard pressure, and the substrate is fixed to the receiving device by vacuum or negative pressure.

[0105] The holding vacuum is preferably a negative pressure between 5 mbar and 950 mbar. In this case, the holding vacuum is the clamping force of the clamping element. In the vacuum clamping section, the pressure is in particular between 0.01 mbar and 1000 mbar, preferably between 0.01 mbar and 800 mbar, even more preferably between 0.01 mbar and 500 mbar, most preferably between 0.01 mbar and 100 mbar, and most preferably between 0.01 mbar and 50 mbar in all. The pressure difference between the greater external pressure and the smaller internal pressure in the vacuum clamping element is therefore the pressure on the substrate that leads to clamping of the substrate.

[0106] Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and on the basis of the drawings. [Brief explanation of the drawings]

[0107] [Figure 1] 1 is a plan view schematically illustrating a vacuum substrate holder according to a first embodiment of the present invention. [Figure 2] FIG. 4 is a plan view schematically illustrating a vacuum substrate holder according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a plan view schematically illustrating a vacuum substrate holder according to a third embodiment of the present invention. [Figure 4a] 4 is a cross-sectional view schematically illustrating the holding surface of the vacuum substrate holder of FIG. 3 having a transition zone in a first embodiment according to the present invention. [Figure 4b] 4 is a cross-sectional view schematically illustrating a holding surface of a vacuum substrate holder having a transition zone in a second embodiment according to the present invention. FIG. [Figure 4c] 10 is a cross-sectional view schematically illustrating a holding surface of a vacuum substrate holder having a transition zone in a third embodiment according to the present invention. [Figure 4d] 10 is a cross-sectional view schematically illustrating a holding surface of a vacuum substrate holder having a transition zone in a fourth embodiment according to the present invention. FIG. [Figure 4e] 10 is a cross-sectional view schematically illustrating a holding surface of a vacuum substrate holder having a transition zone in a fifth embodiment according to the present invention. FIG. [Figure 4f] 10 is a cross-sectional view schematically illustrating a portion of a holding surface of a vacuum substrate holder having a fixed substrate and a transition zone in a sixth embodiment according to the present invention. FIG. [Figure 4g] 10 is a cross-sectional view schematically illustrating a holding surface of the vacuum substrate holder of FIG. 3 having a transition zone in a seventh embodiment of the present invention.

[0108] In these figures, identical components or components with identical functions are given the same reference numerals and show simplified representations of a containment device having a vacuum zone with a fastening element and a transition zone without a fastening element, which are not necessarily drawn to scale.

[0109] FIG. 1 shows a plan view of a receiving device according to the invention or a vacuum substrate holder according to the invention in a first embodiment.

[0110] The vacuum zones 5, 5', 5'' and the transition zones 6, 6', 6'' are arranged in an annular, in particular circular, configuration in the illustrated embodiment.

[0111] The receiving device 1 according to FIG. 1 has a holding surface with a plurality of fastening elements, in particular vacuum fastening elements 4, 4', 4''. These fastening elements 4, 4', 4'' can be implemented in different ways. The outermost fastening element 4 is in particular completely circularly structured. The inner fastening elements are arranged symmetrically relative to the center of the receiving device 1.

[0112] These fixing elements 4', 4'' are embodied as particularly thin recesses which can be evacuated preferably via fluid openings 7 and thus act as vacuum fixing elements.

[0113] These fixing elements 4, 4', 4'' in Figure 1 define vacuum zones 5, 5', 5'', respectively. Figure 1 shows the vacuum zones 5, 5', 5'' arranged symmetrically about the center of the containment device 1.

[0114] These vacuum zones 5, 5', 5'' are separated by transition zones 6, 6', 6''. These transition zones 6, 6', 6'' each separate two different vacuum zones and are not supplied with vacuum. Therefore, these transition zones 6, 6', 6'' do not have any inherent fixing elements.

[0115] The transition zone between the two vacuum zones allows for a gradual vacuum transition from the first vacuum zone to the second vacuum zone, respectively. Transition zone 6' exists, for example, between vacuum zone 5' and vacuum zone 5''.

[0116] The spacing between two vacuum zones is in particular less than 50 mm, preferably less than 25 mm, even more preferably less than 20 mm, most preferably less than 15 mm, and most preferably less than 10 mm altogether. If the vacuum zones are designed as circular segments as in Figure 1, this spacing is the distance between the inner annulus of the outer circular segment and the outer annulus of the inner circular segment.

[0117] The number of anchoring elements per vacuum zone is arbitrary. In particular, there is at least one anchoring element in a vacuum zone, preferably at least two anchoring elements, preferably more than 10, more preferably more than 20, even more preferably more than 50, and most preferably more than 100 anchoring elements. In Figure 1, one anchoring element is present in the vacuum zone.

[0118] A plurality of successively arranged vacuum zones can be controlled, in particular activated or deactivated, so that the local clamping of the substrate can be controlled, in particular a vacuum zone is activated by switching all clamping elements within the vacuum zone.

[0119] The accommodation device 1 can further comprise different sensors 8, in particular pressure measurement sensors and / or distance sensors. In the base body 2 of the accommodation device 1, measuring holes 3 are provided in the holding surface for measuring process parameters from the rear side of the substrate.

[0120] In the center of the substrate holder 1 there may be a deformation element, in particular a pin or a nozzle, as a curvature changing means.

[0121] FIG. 2 shows a simplified plan view of the storage device 1′, in which the vacuum zones 5, 5′, 5″, 5′″ and the transition zones 6, 6′, 6″, 6′″ present between them are arranged in a number of rings, preferably annular, surrounding the center of the storage device 1′.

[0122] The clamping elements 4, 4', 4'', 4''' shown in a simplified manner are each evacuated via a separate and uniquely controllable fluid opening 7. In a particularly preferred embodiment, these clamping elements 4, 4', 4'', 4''' are recessed with respect to the substrate holder surface, in particular milled.

[0123] If a loading pin is used (not shown), the loading pin may be provided with, for example, a seal.

[0124] The accommodation device 1' according to Fig. 2 has primarily transparent measurement holes 3 to enable measurements to be carried out from the rear side of the substrate for monitoring process parameters. Preferably, at least the upper substrate holder has the measurement holes. These measurement holes are, in particular, designed to be shieldable and / or gas-tight.

[0125] A distance sensor 8 can be incorporated into the receiving device 1', allowing the distance between the holding surface and the charged substrate to be measured at any given time.

[0126] FIG. 3 shows a plan view of a storage device 1'' according to a third embodiment.

[0127] The fixing elements 4, 4', 4'' are evacuated via a particular channel or fluid opening 7, in particular a recessed, preferably milled recess, inside which a projection 9 is present.

[0128] The fixing elements 4, 4', 4'' in FIG. 3 define one vacuum zone 5, 5', 5'' respectively.

[0129] FIG. 3 shows vacuum zones 5 , 5 ′, 5 ″ arranged symmetrically about the center of the containment device 1 .

[0130] These vacuum zones 5, 5', 5'' are separated by transition zones 6, 6'. Transition zones 6, 6' each separate two different vacuum zones, and no vacuum is actively applied thereto. Transition zone 6 allows for a gradual vacuum transition between vacuum zone 5 and vacuum zone 5'. Similarly, transition zone 6' allows for a gradual vacuum transition between vacuum zone 5' and vacuum zone 5''.

[0131] FIG. 3 shows an enlarged fragment of the transition zone 6. The vacuum zone and the transition zone are separated by a vacuum seal. The surface of the transition zone 6 may be structured. The structure 10 may, for example, be a further vacuum seal lowered from the level of the substrate holding surface. The vacuum zones 5, 5' with the fixing elements 4, 4' are evacuated via separate fluid openings 7 and are structured as protruding surfaces. The fixing of the substrate is achieved by evacuating the spaces between the protrusions. Different embodiments of the transition zone are shown in FIGS. 4a to 4f and are explained in more detail.

[0132] In the receiving device 1" according to Fig. 3, several vacuum zones, in particular several vacuum zones located next to each other, can be grouped and switched on together, which advantageously allows for switching on a relatively large surface as required, making the joining process and removal from the receiving device 1" even more flexible and precise.

[0133] The optimum number of vacuum zones per circumference, as well as the optimum number of vacuum zones along the radial direction, and the optimum design of the transition zones therebetween, can be optimized, inter alia, by empirical measurements and / or simulations.

[0134] In this case, the two substrates to be bonded to one another are fixed in such a way that the influence factors on the formed and propagating bond wave are reduced as much as possible, especially by fixation, especially by controllable fixation over a large surface area. The gradual vacuum transition from one vacuum zone to the next on the holding surface of the receiving device, with a transition zone where no vacuum is actively supplied, makes it possible to reduce the distortions induced by the bond, since a sudden change in the framework conditions for the bond wave is avoided.

[0135] 4a shows a schematic, not-to-scale, cross-sectional view of a first embodiment of the holding surface of the receiving device. A transition zone 6 is present between two vacuum zones 5 and 5'. The vacuum zones 5, 5' have a protruding structure with protrusions 9 having a height H1 and are evacuated via fluid openings 7, 7'. No vacuum is actively applied to the transition zone 6.

[0136] The width or diameter of the receiving ridges, in particular the protrusions, is in particular less than 5 mm, preferably less than 2 mm, even more preferably less than 1 mm, most preferably less than 500 μm, and most preferably less than 200 μm altogether. In a preferred embodiment, the width is between 100 μm and 2 mm.

[0137] The height of the accommodation ridges, in particular the protrusions, is in particular less than 2 mm, suitably less than 1 mm, even more preferably less than 500 μm, most preferably less than 200 μm.

[0138] In particular, the ratio between the width or diameter of the receiving ridge and the height of the receiving ridge is greater than 0.01, preferably greater than 1, even more preferably greater than 2, most preferably greater than 10, and most preferably greater than 20 altogether.

[0139] The vacuum zones 5, 5' with the fastening elements 4, 4' are used for fastening the substrate (not shown). A vacuum seal separates the surface of the transition zone 6 from the two vacuum zones 5, 5'. The transition zone according to FIG. 4a additionally shows two further structures, in particular vacuum seals. Between the two vacuum seals in the transition zone 6 there is an intervening space 11 in each case.

[0140] The gradual vacuum transition from one vacuum zone 5, 5' to the other is determined by the height of the vacuum seal 10 between the two vacuum zones 5, 5' and the selection of the amount and height of the structures in the transition zone 6 between them. The embodiment according to FIG. 4a shows two further vacuum seals as structures 10. Due to the design of the transition zone 6, the flow resistance in the area of ​​the vacuum seal 10, the transition zone with the intervening space 11 and the area of ​​the vacuum zones 5, 5' is controlled so that equalization between the two vacuum zones 5, 5' in the transition zone 6 occurs, since the vacuum in the transition zone 6 is compensated for by leakage in the vacuum seals and structures 10.

[0141] The recession of the vacuum seal 10 relative to the substrate placement plane on the holding surface of the receiving device defines the gap height h that must be allowed for leakage. The vacuum seal can be recessed, for example, between 100 nm and 5 μm, preferably between 100 nm and 3 μm, and even more preferably between 100 nm and 500 nm. In comparison, the height H1 of the protrusion, which defines the height of the holding surface for the substrate, is, for example, between 100 μm and 1000 μm.

[0142] Figure 4b shows a second embodiment of the transition zone 6'. In this embodiment, too, the vacuum seal 10' is recessed relative to the substrate placement plane (height of the protrusion H1). The intervening space 11' is filled to a height H2 according to Figure 4b, which results in a smaller volume of the intervening space 11' in the transition zone 6'. This allows for a controlled equalization between the two vacuum zones 5, 5' in the transition zone 6'.

[0143] FIG. 4c shows a third embodiment of the transition zone 6″, which has an additional vacuum seal in the transition zone 6″. According to FIG. 4c, the vacuum seal 10″ has a height H3 that is significantly smaller than the height H1 of the protrusion for placing the substrate. The vacuum zones 5, 5′ are evacuated via the fluid openings 7, 7′, whereas no vacuum is actively supplied to the transition zone 6″.

[0144] In a fourth embodiment of the transition zone 6'" according to FIG. 4d, the vacuum seal 10'" between the vacuum zone 5, 5' and the transition zone 6'" or the vacuum seal 10''' present between the two vacuum zones 5, 5' in the transition zone 6'" is not recessed relative to the surface of the substrate rest. Instead, a number of small channels 12 are machined in the vacuum seal 10'" at several points along its extension at regular intervals. In this case, the cross section of these channels 12 is selected to be significantly smaller than the cross section in the region of the protrusions 9. The cross section of the channels is in particular 10 times smaller, preferably 30 times smaller, more preferably 50 times smaller, even more preferably 80 times smaller, most preferably 100 times smaller, and most preferably 200 times smaller than the cross section in the region of the protrusions 9. This ensures that the pressure drop is mainly in the region of the vacuum seal 10'", providing a uniform vacuum in the region of the vacuum zones 5, 5'. Between the two vacuum seals with the channels there is an intervening space 11'".

[0145] In this case, the leakage cross section or the flow cross section of the sealing structure should be significantly smaller than the cross section of the supply line, in particular by a factor of 2, preferably by a factor of 5, more preferably by a factor of 10, even more preferably by a factor of 30, most preferably by a factor of 50, and most preferably by a factor of 100. This ensures that the leakage is a defined resistance in the system and that the vacuum can be precisely controlled in the desired value in the area of ​​the support surface.

[0146] The axial spacing of the vacuum seals or vacuum structures 10''' is preferably between 0.5 mm and 50 mm, more preferably between 2 mm and 50 mm, even more preferably between 5 mm and 50 mm. The width of the vacuum structures is in particular between 0.5 μm and 1 mm, preferably between 1 μm and 750 μm, more preferably between 5 μm and 500 μm.

[0147] Figure 4e shows the transition zone 6IV 5 shows a fifth embodiment of the present invention, in which the surface of the transition zone is fully filled and has a height H4 smaller than the height H1 of the protrusion or a gap height h relative to the protrusion surface. IV Only the protrusions 9 are recessed. These line structures are arranged on a wide vacuum seal. The axial spacing of the line structures is uniform, in particular 1.5 μm. Preferably, the uniform axial spacing of the line structures is between 0.1 μm and 10 μm, even more preferably between 0.5 μm and 5 μm. The vacuum zones 5, 5' with the protrusions 9 are actively evacuated via the fluid openings 7, 7'.

[0148] 4f shows a cross-sectional view of a portion of the holding surface of a substrate receiving device having a sixth embodiment of a transition zone 6 and a fixed substrate 13. FIG. 4f shows the protrusions 9 with height H, the gap height h of the recessed vacuum seals and structures 10, and the axial spacing t between the structures. The selection of H, h, and t, as well as the number of vacuum seals or structures in the transition zone 6, allows for design optimization of the transition zone 6.

[0149] The uniformity of the substrate clamping from one vacuum zone to the other due to the gradual vacuum transition created across the transition zone also results in a gradual change in the framework conditions for the bond wave, which reduces and uniforms distortion, leading to an increased quality of the bonded product.

[0150] Figure 4g shows a seventh embodiment of the transition zone 6 similar to Figure 4c, with an additional vacuum seal 10 in the transition zone 6. According to Figure 4g, the vacuum seal 10 VThe protrusions 9 have a height H3 that is significantly smaller than the height H1 of the protrusions for supporting the substrate. In this preferred embodiment, a vacuum seal 10 is located between two rows of receiving ridges 9 or protrusion rows. The protrusions 9, which form a holding plane and on which the substrate is supported, also support the substrate in the transition zone 6. The vacuum zones 5, 5' are evacuated via fluid openings 7, 7', whereas no vacuum is actively applied to the transition zone 6. The vacuum seal or sealing structure can be recessed, for example, between 100 nm and 5 μm, preferably between 100 nm and 3 μm, even more preferably between 200 nm and 1 μm, and most preferably between 200 nm and 500 nm, compared to the receiving surface provided by the receiving ridges. Preferably, the axial spacing of the protrusions is between 1 mm and 8 mm, even more preferably between 2 mm and 6 mm. The width or diameter of the receiving ridge, in particular the protrusion, is in particular less than 5 mm, preferably less than 2 mm, even more preferably less than 1 mm, most preferably less than 500 μm, and most preferably less than 200 μm altogether. In a preferred embodiment, the width is between 100 μm and 2 mm. V The width of the projections is smaller than the axial spacing of the projections, in particular less than 5 mm, preferably less than 2 mm, and even more preferably 1 mm or less. [Explanation of symbols]

[0151] 1 Vacuum substrate holder, accommodation device, substrate accommodation device, substrate holder 2 Base 3 measuring holes 4,4',4'',4''' fixed element 5,5',5'',5''' vacuum zone 6,6',6'',6''',6 IV ,6 V Transition Zone 7,7' fluid opening 8 sensors 9. Housing ridge, protrusion 10,10',10'',10''',10 IV ,10 V Seal structure, structure, vacuum seal 11,11',11'',11''',11 V intervening space 12 Flow path, opening 13 PCB H, H1, H2, H3, H4 height h Gap height t Axial spacing of seal structure

Claims

1. A vacuum substrate holder (1) for fixing a substrate (13), comprising: a) a first vacuum zone (5, 5', 5'', 5''') having at least one first fixing element (4, 4', 4'', 4'''); b) a second vacuum zone (5, 5', 5'', 5''') with at least one second fixing element (4, 4', 4'', 4'''); c) accommodation ridges (9) arranged in at least the first vacuum zone (5, 5', 5'', 5''') and in at least the second vacuum zone (5, 5', 5'', 5'''), the accommodation ridges (9) being arranged on holding surfaces provided by the accommodation ridges (9) when the substrate (13) is fixed; d) at least one transition zone (6, 6', 6'', 6''', 6'') separating said first vacuum zone (5, 5', 5'', 5''') and said second vacuum zone (5, 5', 5'', 5''') from each other; ＩＶ , 6 Ｖ ) and The transition zone (6, 6', 6'', 6''', 6 ＩＶ , 6 Ｖ ) includes at least one sealing structure (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ ) in a vacuum substrate holder (1), In the fixed state, the first vacuum zone (5, 5', 5'', 5''') and the second vacuum zone (5, 5', 5'', 5''') are connected to the transition zone (6, 6', 6'', 6''', 6 ＩＶ , 6 Ｖ ) are in fluid communication with each other; The at least one sealing structure (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ ) has at least one opening, and the at least one opening allows the sealing structure (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ ) the cross-sectional area of ​​the flow passage can be preset, and / or The at least one transition zone (6, 6', 6'', 6''', 6 ＩＶ , 6 Ｖ ) each have at least two sealing structures (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ ), and the transition zone (6, 6', 6'', 6''', 6 ＩＶ , 6 Ｖ ) is the at least one transition zone (6, 6', 6'', 6''', 6 ＩＶ , 6 Ｖ The sealing structures (10, 10', 10'', 10''', 10) that are furthest apart from each other ＩＶ , 10 Ｖ ) between the intervening spaces (11, 11', 11'', 11''', 11 Ｖ 1. A vacuum substrate holder (1), characterized in that it forms a

2. The two seal structures (10, 10', 10'', 10''', 10) that are furthest apart from each other ＩＶ , 10 Ｖ 2. The vacuum substrate holder (1) according to claim 1, wherein the flow cross-sectional areas of the respective substrates (1) are the same.

3. The intervening space (11, 11', 11'', 11''', 11 Ｖ The cross-sectional area of ​​the transition zone (6, 6', 6'', 6''', 6 ＩＶ , 6 Ｖ ) of the sealing structure (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ 3. The vacuum substrate holder (1) according to claim 1, wherein the flow cross-section of the substrate holder (1) is greater than the flow cross-section of the substrate holder (1).

4. The intervening space (11, 11', 11'', 11''', 11 Ｖ The cross-sectional flow area of ​​the transition zone (6, 6', 6'', 6''', 6 ＩＶ , 6 Ｖ ) of the sealing structure (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ 3. A vacuum substrate holder (1) according to claim 1 or 2, wherein the cross-sectional flow area of ​​the substrate is 5 times larger, preferably 10 times larger, more preferably 30 times larger, even more preferably 50 times larger, most preferably 100 times larger, and most preferably 200 times larger than the cross-sectional flow area of ​​the substrate.

5. The at least one sealing structure (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ ) have a uniform height (H1, H2, H3, H4) relative to the vacuum substrate holder surface, and the at least one sealing structure (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ The heights (H1, H2, H3, H4) of the at least one sealing structure (10, 10', 10'', 10''', 10') are less than the height (H) of the receiving ridge (9) relative to the vacuum substrate holder surface, so that in a fixed state, the at least one sealing structure (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ 2. The vacuum substrate holder (1) of claim 1, wherein a gap having a gap height (h) is formed between the vacuum substrate holder (1) and the substrate (13).

6. 6. A vacuum substrate holder (1) according to claim 5, wherein the gap height (h) is less than 10 times, preferably less than 30 times, more preferably less than 50 times, even more preferably less than 80 times, most preferably less than 100 times, and most preferably all less than 200 times, than the height (H) of the receiving ridge (9).

7. The at least one sealing structure (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ ) in a fixed state at least partially abuts the substrate (13), and the transition zones (6, 6', 6'', 6''', 6 ＩＶ , 6 Ｖ ) offset flow passages (12) along the at least one sealing structure (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ 3. The vacuum substrate holder (1) according to claim 1, wherein the vacuum substrate holder (1) is formed in a vacuum chamber.

8. 3. A vacuum substrate holder (1) according to claim 1 or 2, wherein the spacing between at least one said first vacuum zone (5, 5', 5'', 5''') and at least one said second vacuum zone (5, 5', 5'', 5''') is less than 50 mm, preferably less than 25 mm, even more preferably less than 20 mm, most preferably less than 15 mm and most preferably all less than 10 mm.

9. At least one of the fixing elements (4, 4', 4'', 4''') of one vacuum zone has at least one fluid opening (7, 7'), and all the fluid openings (7, 7') of each vacuum zone (5, 5', 5'', 5''') together form a total flow area of ​​the respective vacuum zone (5, 5', 5'', 5'''), and the transition zones (6, 6', 6'', 6''', 6''') abutting the respective vacuum zones (5, 5', 5'', 5'''). ＩＶ , 6 Ｖ ) of the sealing structure (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ 3. A vacuum substrate holder (1) according to claim 1 or 2, wherein the cross-sectional flow area of ​​the fixing elements (4, 4', 4'', 4''') of the respective abutting vacuum zones (5, 5', 5'', 5''') is 2 times smaller, preferably 5 times smaller, more preferably 10 times smaller, even more preferably 30 times smaller, most preferably 50 times smaller and most preferably 100 times smaller overall than the total flow area of ​​the fixing elements (4, 4', 4'', 4''') of the respective abutting vacuum zones (5, 5', 5'', 5''').

10. The seal structure (10, 10', 10'', 10''', 10 ＩＶ , 10 Ｖ The cross-sectional flow area of ​​the transition zone (6, 6', 6'', 6''', 6 ＩＶ , 6 Ｖ 3. A vacuum substrate holder (1) according to claim 1 or 2, wherein the total opening area between the receiving ridges (9) of the vacuum zones (5, 5', 5'', 5''') directly abutting the substrate holder (1) is less than 10 times, preferably less than 30 times, more preferably less than 50 times, even more preferably less than 80 times, most preferably less than 100 times, and most preferably all less than 200 times.

11. The vacuum substrate holder has further vacuum zones (5, 5', 5'', 5'''), which are respectively connected to further transition zones (6, 6', 6'', 6''', 6''', 6'''). ＩＶ , 6 Ｖ ), and radially adjacent vacuum zones (5, 5', 5'', 5''') are separated by said further transition zones (6, 6', 6'', 6''', 6''', respectively. ＩＶ , 6 Ｖ 3. The vacuum substrate holder (1) according to claim 1, wherein the substrates are in fluid communication with each other by means of a vacuum pump.

12. 1. An apparatus for bonding substrates, comprising:

3. Apparatus comprising at least one vacuum substrate holder (1) according to claim 1 or 2.

13. A method for bonding substrates, comprising, in particular in the following order, the following steps: i) providing a first substrate (13) on a vacuum substrate holder (1) according to claim 1 or 2; ii) providing a second substrate on a substrate holder; iii) bonding the first substrate (13) to the second substrate; The method includes:

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