Apparatus and method for connecting substrates

Abstract

This invention relates to a method for connecting a first substrate (2o) to a second substrate (2u) at contact surfaces (17u, 17o) of substrates (2o, 2u), the method comprising the following steps, particularly the following process: mounting the first substrate (2o) on a first mounting surface (18o) of a first substrate holder (1o) and mounting the second substrate (2u) on a second mounting surface (18u) of a second substrate holder (1u), wherein the substrate holders (1o, 1u) are arranged in a chamber (3) and contact the contact surfaces (17u, 17o) at a connection initiation surface (10), connecting the first substrate (2o) to the second substrate (2u) from the connection initiation surface (10) to the center of the substrates (2o, 2u). Furthermore, this invention relates to a corresponding apparatus.

Description

Technical Field

[0001] The present invention relates to a method and a corresponding apparatus for connecting a first substrate to a second substrate, according to the parallel claims. Background Technology

[0002] There are many methods in the prior art for joining two substrates together. Independent of the basic bonding process, it is almost always the case that at least one first substrate is convex and makes contact with the second substrate at its center. Full-surface bonding then occurs due to continuous contact from the center to the edge of the substrates. This type of contact is found again in fusion bonding and metal bonding, as well as in temporary bonding. Other contact possibilities exist, particularly in cases where the substrate is fixed to a film. Thus, the film is often laminated onto the substrate. In this case, the contact process mainly occurs through manipulation of the film. In this case, the substrate is fixed and kept flat. A special device called a laminator then pulls the film above the substrate. The film can be fixed to the substrate by mechanical elements (especially rollers) or simply by lowering it. Summary of the Invention

[0003] The objective of this invention is to provide an apparatus and method for connecting two substrates, and to increase the accuracy of the connection using the apparatus and method.

[0004] This task is accomplished using the features of the independent claims. Advantageous developments of the invention are described in the independent claims. All combinations of at least two features described in the specification, claims, and / or drawings also fall within the scope of the invention. For the stated value ranges, values ​​falling within the mentioned limits should also be considered as limit values ​​disclosed and can be claimed in any combination.

[0005] The present invention relates to a method for connecting a first substrate to a second substrate at a contact surface between the first substrate and the second substrate, the method comprising the following steps, particularly the following process:

[0006] - The first substrate is mounted on a first mounting surface of a first substrate holder and the second substrate is mounted on a second mounting surface of a second substrate holder, wherein the substrate holder is arranged in a chamber, particularly a chamber that can be sealed by a vacuum seal.

[0007] - The contact surface is made in contact with the starting surface of the connection, especially the starting surface of the annular connection.

[0008] - Connect the first substrate to the second substrate from the connection starting surface to the center of the substrate.

[0009] Preferably, the chamber pressure in the chamber is increased after contact and / or during connection.

[0010] In this development of the invention, it is specified that the connection starting surface is arranged at the outer peripheral edge of at least one of the contact surfaces.

[0011] More preferably, the first substrate is concave relative to the second substrate before contact, specifically by mounting the first substrate on the corresponding concave first mounting surface.

[0012] According to another aspect of the invention, the connection starting surface, particularly the outer periphery closed, is configured to be distributed in a ring-shaped manner, particularly in a circular manner, preferably concentric with the center of the substrate.

[0013] A particularly advantageous embodiment of the invention is wherein the first substrate and / or the second substrate are fixed to the first mounting surface and / or the second mounting surface only in the region of the side edge of the contact surface.

[0014] The present invention relates to an apparatus for connecting a first substrate to a second substrate at a contact surface between the first substrate and the second substrate, the apparatus comprising:

[0015] - The first mounting surface of the first substrate holder (1o) is used to mount the first substrate.

[0016] - The second mounting surface of the second substrate holder is used to mount the second substrate.

[0017] - A chamber, particularly one that can be sealed in a vacuum-sealed manner, in which the substrate holder is arranged.

[0018] - A component for contacting the contact surface, particularly at the annular connection starting surface.

[0019] - A component for connecting the first substrate to the second substrate from the connection starting surface to the center of the substrate.

[0020] This invention is based on the concept of connecting the substrates from the annular connection initiation surface to the center of the contact surface. Preferably, at least one of the two substrates (preferably the second substrate and / or the upper substrate) is concavely deformed relative to the other substrate before contact to align the contact surface. Deformation specifically means a deviation of the substrates from their initial state (especially their initial geometry). Preferably, the connection is initiated after contact with the contact surface (particularly by lowering / releasing the first substrate / upper substrate, preferably supported by increased pressure). Corresponding connecting members are provided according to the device.

[0021] One particularly independent aspect of the invention relates to a method and apparatus for bonding / laminating a second substrate (particularly a wafer) onto a second substrate (particularly another wafer or thin film). Specifically, the second substrate may also be referred to as a support. In this case, the concept is based on the idea of ​​securing a concave substrate to a concavely designed substrate holder, making concave contact (particularly pre-fixed) with another substrate at the connection initiation surface, and subsequently using a pressure difference to generate uniform pressure on the surfaces of the substrates to be bonded, thereby producing a full-surface bond. This pressure difference is generated between the cavity and chamber space formed by the contacted surfaces of the substrates. It is also conceivable that the substrate holder can be bent, particularly concavely bent, by means of a control element.

[0022] Uniform pressure distribution advantageously ensures a uniform pressing force of the second substrate on the first substrate, because pressure is applied evenly over the entire surface of the substrate due to the use of uniform pressure. Furthermore, easily generated pressure differentials can be used, and pins or other mechanical components that engage with only localized forces can be omitted.

[0023] Another aspect of the invention involves using isostatic pressure to fix a particularly rigid substrate to another substrate, which may also be rigid. In this case, the substrate to be fixed is concave before a pressure difference is generated and is thus rested only by means of its edge surfaces (the starting surfaces for connection). The concept according to the invention is not limited to bonding or laminating a film to a substrate, but is preferably related to two particularly rigid substrates. The concept according to the invention can also be used, particularly, for fusion bonding or metal bonding. However, the method and apparatus according to the invention are preferably used for temporary bonding. The thickness of the film used according to the invention is between 1 µm and 4000 µm, preferably between 1 µm and 3500 µm, more preferably between 1 µm and 3000 µm, most preferably between 1 µm and 2500 µm, and particularly preferably between 1 µm and 2000 µm.

[0024] substrate

[0025] Referring to different types of substrates, a framework with a film is considered, particularly as a wafer having an adhesive layer (especially a structured one). Such substrates are known to those skilled in the art. The substrate may have an adhesive layer. The thickness of the adhesive layer is between 1 µm and 250 µm, preferably between 2 µm and 200 µm, more preferably between 3 µm and 100 µm, most preferably between 3 µm and 50 µm, and particularly preferably between 3 µm and 10 µm.

[0026] substrate holder

[0027] As a substrate holder, a substrate holder having a flat mounting surface or a concave mounting surface is particularly considered. The substrate holder preferably has fasteners for holding / fixing / mounting the substrate. The fasteners may particularly be…

[0028] 1. Mechanical fasteners, especially clamps, and / or

[0029] 2. Vacuum fasteners, particularly those with individually controllable and / or interconnected vacuum tracks, and / or

[0030] 3. Electrical fasteners, especially electrostatic fasteners, and / or

[0031] 4. Magnetic fasteners, and / or

[0032] 5. Adhesive fasteners, especially gel-coated fasteners, and / or

[0033] 6. Fasteners with adhesive, especially controllable surfaces.

[0034] In particular, the fastener is electronically controllable. Vacuum fasteners are a preferred type of fastener.

[0035] Vacuum fasteners preferably consist of multiple vacuum tracks appearing on the surface (mounting surface) of the substrate holder. These vacuum tracks are preferably individually controllable. In applications where this is more technically feasible, some vacuum tracks are combined into individually controllable, and therefore can be evacuated or filled, vacuum track segments. However, each vacuum segment is independent of the others. This provides the possibility of constructing individually controllable vacuum segments. These vacuum segments are preferably constructed in a ring shape. This allows for targeted, radially symmetrical, and particularly inside-out securing of the substrate holder to the substrate and / or release of the substrate from the substrate holder, and vice versa. Such a vacuum segment design is disclosed in document WO2017162272A1.

[0036] At clearly defined locations or throughout the entire volume, the substrate holder can be transparent to a portion of the electromagnetic spectrum, particularly to UV and / or visible and / or infrared light. It is also conceivable that the substrate holder has passageways, particularly holes, most preferably drilled holes, at multiple locations, through which clear viewing of the substrate holding side can be ensured. In particular, these construction techniques ensure viewing of alignment marks that can be located on the substrate.

[0037] The remainder of the text describes more precisely the preferred substrate holder according to the invention.

[0038] The substrate holder particularly has a concave mounting surface. The curvature of the concave mounting surface is preferably constant and / or rotationally symmetric. Specifically, the curvature of the concave mounting surface can be described by the radius of curvature. The radius of curvature is the radius of the closely spaced circle at and through the center of the concave mounting surface. The radius of curvature is between 10 mm and 10... 8 Between 10 mm, preferably between 10 mm 3 mm and 10 8 Between 10 mm, more preferably between 10 mm 4 mm and 10 8 Between 10 mm, most preferably between 10 mm. 5 mm and 10 8 Between 10 mm, particularly preferably between 10 mm 6 mm and 10 8 Between mm. In a particular embodiment, it is conceivable that the curvature of the concave mounting surface is not constant, but changes from the center toward the edge, particularly continuously. In this specific embodiment, a different radius of curvature will be set at each point on the mounting surface.

[0039] In the first embodiment of the concave mounting surface, the curvature is the same at every location, that is, uniform.

[0040] In the second embodiment of the concave mounting surface, the curvature is constant at least along the circle, that is, it changes only from the center toward the edge. The curvature is correspondingly radially symmetrical.

[0041] In the third embodiment of the concave mounting surface, the curvature is anisotropic, i.e., dependent on the radial position and direction. In this particular embodiment, for example according to the invention, the first substrate can be fixed such that, upon contact with a flat second substrate, the first substrate does not rest entirely along the outer peripheral edge of its contact surface, but only a portion of the outer periphery of its side edge contacts the second substrate. An example of this embodiment is a saddle deposited on a flat surface. This embodiment according to the invention particularly allows for the evacuation of the space between the two contacting substrates after contact has occurred.

[0042] Furthermore, the deformability of the concave mounting surface is used to characterize the substrate holder according to the invention.

[0043] In a first embodiment according to the invention, the substrate holder according to the invention has a static concave mounting surface. The concave mounting surface is manufactured, in particular, by a milling process and / or a grinding process and / or a polishing process. It is also conceivable to manufacture it by a rotational process, wherein a curable liquid is rotated and cured in a column, such that a concave mounting surface is formed during curing.

[0044] In a second embodiment of the invention, the substrate holder according to the invention has a dynamically changeable concave mounting surface. Since the deformation of the concave mounting surface occurs at relatively small dimensions, particularly in the micrometer to millimeter range, the use of functional materials and raw materials is conceivable. In particular, it is possible to...

[0045] • Magnetorheological materials and / or

[0046] • Electrorheological materials and / or

[0047] • Shape memory alloys and / or

[0048] • Gel pack and / or

[0049] • Mechanical parts and / or

[0050] • Electrical components and / or

[0051] • Magnetic components

[0052] Used to adapt to concave curvature.

[0053] Furthermore, regarding other functional characteristics that characterize the substrate holder according to the invention, these additional functional characteristics are described below based on embodiments of the invention.

[0054] According to a first embodiment of the invention, the substrate holder is opaque, preferably completely opaque (i.e., impermeable), for use in measuring electromagnetic radiation on the surface of a substrate. Specifically, this measurement is used to control the substrate holder during alignment of the substrates relative to each other.

[0055] In a second embodiment of the invention, the substrate holder is transparent, particularly partially, and preferably completely transparent, for use in measuring electromagnetic radiation on the substrate surface. Transparency may also apply only to a portion of the substrate holder.

[0056] Transparency is described by transmittance, which indicates the ratio of transmitted radiation to emitted radiation. However, transmittance does not depend on the thickness of the transmitted object and is therefore not a material-specific property. Therefore, transmittance values ​​are described with reference to a unit length of 1 cm. With respect to a selected thickness of 1 cm and for each selected wavelength, the material of the transparent portion of the substrate holder particularly has a transmittance greater than 10%, preferably greater than 20%, more preferably greater than 50%, most preferably greater than 75%, and most preferably greater than 99%.

[0057] In a third embodiment of the invention, the substrate holder has a passage, particularly a drilled hole, through which the substrate or substrate stack can be observed.

[0058] In a fourth embodiment of the invention, the substrate holder is configured such that a concave mounting surface is created by a layer or component capable of dynamically adapting, particularly through volume changes. This embodiment is particularly suitable for constructing a substrate holder with a dynamically changeable mounting surface according to the invention.

[0059] In a fifth embodiment of the invention, the substrate holder is configured such that the concave mounting surface can be bent by a control member, particularly a mechanical and / or hydrodynamic and / or electrical control member. In this case, the elasticity of the component forming the concave mounting surface is utilized. Since the radius of curvature of the concave mounting surface according to the invention is very large, i.e., the deflection is very small, a minimal translation of the component connected to the control member is sufficient to achieve a change in curvature. The control member is controlled, in particular, by a control element for adjusting the curvature.

[0060] Facilities (equipment)

[0061] The present invention includes a facility consisting of at least two substrate holders in a chamber, wherein the chamber can be sealed in a pressure-sealed manner.

[0062] At least one of the substrate holders may be fixed and / or rotatable and / or translational. Specifically, rotation is possible about at least one axis, preferably three axes orthogonal to each other. Specifically, translation is possible along at least one axis, preferably three axes orthogonal to each other. The facility preferably has components for coarse and / or fine adjustment of the substrate relative to each other.

[0063] The component used for coarse adjustment is preferably a mechanical stop element that restricts the translational freedom of the substrate. For example, a pin can be envisioned, causing the substrate to move toward the pin until contact is established.

[0064] The component used for fine adjustment is preferably an optical element, particularly an optical system capable of detecting alignment marks preferably located on a substrate. The detected alignment marks are recorded by a camera and processed by means of software and / or hardware and / or firmware. Accordingly, the fine adjustment (alignment) is controlled by a control device.

[0065] The resolution of the optical system is better than 100 µm, preferably better than 10 µm, more preferably better than 1 µm, most preferably better than 500 nm, and especially preferably better than 50 nm.

[0066] The chamber can be completely evacuated and filled with any gas mixture or a single gas. The temperature of the chamber and / or the substrate holder according to the invention can be controlled, i.e., heated and / or cooled. The chamber and / or the substrate holder can be controlled, particularly, to a temperature between -75°C and 300°C, preferably between -50°C and 250°C, more preferably between -25°C and 200°C, most preferably between 0°C and 150°C, and especially preferably between 25°C and 100°C.

[0067] method

[0068] In the first process step according to the invention, a first substrate is loaded onto a first substrate holder according to the invention. The mounting surface of the first substrate holder is concave, such that the first substrate to be mounted on the mounting surface is similarly concave by means of mounting on the mounting surface. Specifically, a second substrate is simultaneously loaded and secured on a second mounting surface of the second substrate holder. In particular, the second substrate holder may be designed identically to the first substrate holder. However, preferably, the second substrate holder is a substrate holder with a flat mounting surface. The mounting of the second substrate can be performed before, during, or after the mounting of the first substrate.

[0069] In the second process step, the first substrate is aligned relative to the second substrate. In this case, the alignment can be performed, particularly mechanically and / or optically. If the alignment is only a coarse alignment process used, particularly during temporary bonding, it is preferably performed purely mechanically. However, it is preferable to align the two substrates with each other using alignment marks, particularly by means of optical components.

[0070] At the latest, in the third process step according to the invention, within the first process according to the invention, the two substrate holders and the chambers therein are at least partially evacuated. This process can be performed before and / or during the mounting and / or alignment of the substrates. By evacuating the chambers, it is ensured that no molecules and / or atoms are located between or deposited on the two substrates. Especially in the case of non-circular contact (connection starting surface), evacuation can also continue after contact, particularly in a continuous manner. Preferably, the two substrates are made in a circular contact across the entire surface, particularly at the edges of the substrates. Therefore, evacuation is preferably performed before this contact process step.

[0071] The pressure in the chamber is reduced (evacuated) to less than 1 bar, preferably less than 10 bar. -2 millibars, more preferably less than 10 -4 millibars, preferably less than 10 -6millibars, preferably less than 10 -8 Millibars. This specifically ensures that no atoms or molecules are located between the substrates when the two substrates are in full-surface contact via additional process steps according to the invention, because atoms and molecules between the substrates no longer have the possibility of leaving the intermediate space after the annular, peripherally closed contact. That is, the intermediate space is then hermetically sealed by contact along the joint initiation surface.

[0072] If the process according to the invention is used for the fusion bonding of two substrates, enclosed atoms and molecules may generate bubbles between the substrates, which would render the substrate stack almost unusable. Conversely, if the method according to the invention is used for temporary bonding using an adhesive, small amounts of gas between the substrates can be tolerated because the adhesive used can accommodate a certain amount of gas.

[0073] In another embodiment of the invention, the process according to the invention is used for hybrid bonding. Hybrid bonding is a fusion bonding between two hybrid surfaces. The hybrid surface is a surface composed of electrical regions and dielectric regions. The electrical regions are preferably contacts of functional components manufactured beneath the dielectric layer. The electrical regions are thus also referred to as through-silicon vias (TSVs). The surface of the electrical regions is preferably slightly recessed relative to the surface of the dielectric regions.

[0074] In this case, the height difference between the surfaces of the electrical region and the dielectric region is less than 1 µm, preferably less than 500 nm, more preferably less than 50 nm, most preferably less than 5 nm, and particularly preferably less than 1 nm. Due to the preferred recessed electrical region, the bonding wave of the fusion bonding can easily move over the dielectric region without being hindered in its progress by the electrical region.

[0075] Following the fusion bonding above the dielectric regions, the substrate stack is heat-treated. This heat treatment preferably causes the opposing electrical regions of the two substrates to expand due to thermal load, causing the electrical regions to contact each other and permanently connect via metallic bonding (particularly metallic diffusion bonding). Hybrid bonding therefore has the advantage that the connection between the two substrates can be manufactured very easily and cost-effectively through the fusion process.

[0076] The method according to the invention particularly advantageously demonstrates the possibility of forming such a hybrid bond. Advantageously, in the process according to the invention, the connection of the two substrates is preferably performed at the periphery under vacuum. Advantageously, after the two substrates have (particularly fully, peripherally) contact, gas is no longer present between the substrates. By removing the gas between the substrates, potential influencing factors that could affect the progressive bonding wave are eliminated. The convexly bent substrate (particularly the upper part) is stabilized in a dome shape by its elastic properties and its periphery to the second substrate when viewed from the outside.

[0077] Due to the increased pressure, it is now possible to perform targeted and, in particular, controlled flattening of bent substrates without considering the resistance of gas between the substrates. The bonding wave now advantageously extends from the periphery to the center.

[0078] In the fourth process step, the two substrates are brought closer together relative to each other, preferably after the concave first substrate and the second substrate have made contact along the connection initiation surface. Alternatively, it is conceivable that the relative movement between the two substrates may end even before they make contact. In this case, the fasteners of the upper substrate holder are released, and the upper substrate descends onto the lower substrate over a relatively short distance of a few millimeters, preferably a few micrometers, more preferably a few nanometers. According to the invention, after the concave upper substrate has made contact with the lower substrate along its periphery, the two substrates are pre-fixed along their periphery by a surface mechanism.

[0079] In the fifth process step, pressure is increased in the chamber. Specifically, a valve leading to the atmosphere is opened, thereby restoring atmospheric pressure within the chamber. However, it is also conceivable to introduce a gas or gas mixture into the chamber, preferably composed of inert gas atoms or molecules. By generating the increased pressure, particularly by a compressor, the concave substrate is continuously, preferably abruptly, flattened, as a pressure difference is established between the chamber space and the cavity separated from the chamber space by the contact between the substrates.

[0080] By introducing gas or a gas mixture in a controlled and slow manner, and in particular by controlling and very slowly flattening a bent substrate.

[0081] In a particular extension according to the invention, during the controlled and slow flattening of the bent substrate, continuous monitoring is performed on the bent substrate and / or the entire substrate stack and / or the intermediate space between the two substrates. Preferably, in particular, the alignment accuracy between the various features of the two substrates is checked. According to the invention, it is particularly conceivable that defective alignments can be identified even during the flattening of the bent substrate, and the process can then be interrupted. In this case, the more curved upper substrate is preferably again secured by the substrate holder according to the invention and removed from the lower substrate. Subsequently, in the apparatus according to the invention, improved alignment can be re-performed between the two substrates.

[0082] In the process steps according to the invention, the edge of the concave-bent substrate continuously migrates radially outward, while the center of the first substrate approaches the second substrate. Specifically, contact between the two substrates is maintained throughout the process steps according to the invention, ensuring that no contaminants enter between the substrates.

[0083] This process is also performed even when the first substrate and the second substrate are not in complete contact.

[0084] The previously described process may be modified and differs only in a few points described below.

[0085] In the third process step, unlike the previously described process, the chamber is not evacuated. In particular, the chamber remains open to the atmosphere.

[0086] Therefore, in the fifth process step, an overpressure relative to the external atmosphere is applied to the chamber. Specifically, the chamber is hermetically sealed (by pressure sealing) for this purpose. However, it is also conceivable that the chamber is opened to the atmosphere via a valve, where an overpressure is generated within the chamber by a high volumetric flow rate.

[0087] Features disclosed according to the apparatus should also be regarded as features disclosed according to the method, and vice versa. Attached Figure Description

[0088] Other advantages, features, and details of the invention will become apparent from the following description of preferred embodiments, and based on the accompanying drawings. In the drawings:

[0089] Figure 1a The first process step of an embodiment of the method according to the present invention is shown.

[0090] Figure 1b It shows that according to Figure 1a The second process step of the implementation method,

[0091] Figure 1c It shows that according to Figure 1a The third process step of the implementation method,

[0092] Figure 1dIt shows that according to Figure 1a The fourth process step of the implementation method,

[0093] Figure 1e It shows that according to Figure 1a The fifth process step of the implementation method,

[0094] Figure 1f It shows that according to Figure 1a The sixth process step of the implementation method,

[0095] Figure 2 A first embodiment of the substrate holder according to the present invention is shown.

[0096] Figure 3 A second embodiment of the substrate holder according to the present invention is shown.

[0097] Figure 4 A third embodiment of the substrate holder according to the present invention is shown.

[0098] Figure 5 A fourth embodiment of the substrate holder according to the present invention is shown.

[0099] Figure 6 A fifth embodiment of the substrate holder according to the present invention is shown.

[0100] Figure 7 A first embodiment of the substrate is shown.

[0101] Figure 8 A second embodiment of the substrate is shown, and

[0102] Figure 9 A third embodiment of the substrate is shown.

[0103] In these figures, the same parts or parts with the same function are labeled with the same reference numerals.

[0104] All diagrams are not drawn to scale to simplify illustrations and facilitate understanding. In particular, the curvature of the substrate is depicted excessively. Detailed Implementation

[0105] Figure 1a The first process step is illustrated, in which a first substrate 2o is loaded and secured to a first mounting surface 18o of a first substrate holder 1o. Simultaneously, a second substrate 2u is secured to a second mounting surface 18u of a second substrate holder 1u. Preferably, the securing of both substrates 2u and 2o occurs within the chamber 3. However, it is also conceivable that substrates 2u and / or 2o are secured to substrate holders outside the chamber 3 and then transported into the chamber 3 using said substrate holders.

[0106] Figure 1b The second process step is shown, in which two substrates 2u, 2o are aligned relative to each other, particularly their contact surfaces 17u, 17o. This alignment can be coarse or fine. Fine alignment is preferably performed using alignment marks (not shown, as they are known by themselves) and an optical system 9. Preferably, alignment is performed in the x and / or y directions (velocity v). x v y The alignment is performed on and / or in the rotational direction of the substrates 2u, 2o. The curvature of the upper substrate 2o is shown in a very exaggerated manner in this figure. For the optical alignment of the two substrates 2u, 2o relative to each other, the contact surfaces 17u, 17o can be considered to be more or less parallel to each other.

[0107] Figure 1c The third process step is illustrated, in which two substrates 2u, 2o are brought relatively close together, specifically by the relative movement (velocity v) of the two substrate holders 1u, 1o relative to each other. z The evacuation of chamber 3 should begin no later than this process step, generating the lowest possible chamber pressure p within chamber 3. However, vacuum generation can begin even before the third process step and at the contact of substrates 2u and 2o ( Figure 1d Completed before ).

[0108] Figure 1d The fourth process step is shown, in which the concave first substrate 2o is fixed onto the second substrate 2u. If the concave first substrate 2o is located on the upper substrate holder 1o, the first substrate 2o can contact the second substrate 2u by approaching until contact is made or by lowering it. Preferably, contact is initially made only at the connection initiation surface 10. The connection initiation surface 10 is formed at the beginning of contact between the contact surfaces 17u and 17o of the substrates 2u and 2o. Contact is initially made along the side edges 2r and 2r' of the contact surfaces 17u and 17o, particularly complete contact.

[0109] Figure 1e The fifth process step is shown, wherein the chamber pressure p1 in chamber 3 is set to be greater than the chamber pressure p0 that exists directly before contact. Due to the pressure difference thus formed between the cavity 11 formed by the concave deformation of the first substrate 2o and the chamber space 12 located outside the substrates 2u and 2o, the pressure (especially the isotropic pressure) acts on the exposed first substrate 2o and presses it against the second substrate 2u supported by the second substrate holder.

[0110] Figure 1f The sixth process step is shown, in which a connection is made between the first substrate 2o and the second substrate 2u, particularly a bonding.

[0111] In the remainder of the text, various embodiments of the first substrate holders 1o, 1o', 1o'', 1o''', 1o'''' are described. Preferably, the first substrate holders 1o, 1o', 1o'', 1o''', 1o'''' according to the invention are composed of multiple components. The illustrated substrate holders 1o, 1o', 1o'', 1o''', 1o'''' are schematically shown with the minimum necessary number of components that are important for the function according to the invention. Otherwise, the substrate holders 1o, 1o', 1o'', 1o''', 1o'''' may have common features not shown herein.

[0112] Figure 2 A first embodiment of a solid first substrate holder 1o is shown. The substrate holder 1o is particularly impermeable to electromagnetic radiation from the UV, visible, and infrared ranges. The substrate holder 1o has fasteners 7 for securing the first substrate 2o to a static concave mounting surface 18o.

[0113] Figure 3 A second embodiment of the transparent substrate holder 1o' is shown. Due to its transparency, features on the substrate, particularly alignment marks, can be identified and / or measured by means of the optical system 9 through the substrate holder 1o'.

[0114] Figure 4 A third embodiment of a substrate holder 1o'' with a drilled hole 4 is shown, through which features of a substrate 2o fixed to the substrate holder 1o'' can be identified and / or measured by means of an optical system 9.

[0115] Figure 5 A fourth embodiment of a substrate holder 1o''' with a material layer 5 is shown, which may be electrically and / or magnetically and / or thermally connected, causing volume shrinkage or volume expansion. This volume change mainly occurs in the range of cubic micrometers to cubic millimeters. Although the volume change is small, it can thus alter the concave mounting surface.

[0116] For example, material layer 5 can be a magnetorheological, electrorheological, or shape memory alloy. Shape memory alloys, in particular, can change volume and thus shape of the concave mounting surface 18o through thermally induced phase transitions. If material layer 5 is a magnetorheological or electrorheological layer, corresponding electronic and / or electrical components must be disposed in the substrate holder 1o''' to generate a magnetic or electric field that causes a change in volume of the concave mounting surface 18o due to the physical effects of material layer 5. These components are not shown for clarity. In particular, these components are coils or electrodes.

[0117] Figure 6A fifth embodiment is shown, in which the substrate holder 1o'''' can be modified via the control member 8 to alter the concave mounting surface 18o. The control member 8 can be, in particular...

[0118] • Mechanical control components

[0119] • Pneumatic control components

[0120] • Hydraulic control components

[0121] • Electrically controlled components, especially piezoelectric elements.

[0122] In particular, multiple control components 8 can be distributed in the substrate holder 1o'''' to locally vary the curvature of the concave mounting surface 18o.

[0123] The features of the different substrate holders 1o, 1o', 1o'', 1o''', 1o'''' described can be combined with each other to produce a novel substrate holder according to the invention. Therefore, it is conceivable to produce a substrate holder whose combination comes from... Figure 4 Drilling of the substrate holder 1o'' and Figure 5 The material layer 5 of the substrate holder 1o'''. These combinations are also clearly disclosed therein.

[0124] Other figures illustrate different substrates used in the processes and embodiments according to the invention. These substrates may be located, in particular, on the upper substrate holder 1o or the lower substrate holder 1u. However, in particular, substrates 2' and 2'' are referred to as supports and are preferably located on the lower substrate holder 1u. In the case of fusion bonding, substrate 2 will also be present on the lower substrate holder.

[0125] Figure 7 The simplest embodiment of substrate 2 is shown. Substrate 2 is preferably an unstructured or structured wafer 13.

[0126] Figure 8 A substrate 2' consisting of a wafer 13 and an adhesive layer 14 are shown. The adhesive layer 14 is preferably a bonding adhesive and is applied to the wafer 13, for example, by a spin coating process.

[0127] Figure 9 A substrate 2'' consisting of a thin film 16 stretched onto a frame 15 is shown. The thin film 16 preferably has an adhesive layer 14 on its surface. Apparatus and methods for connecting the substrates are also described.

[0128] List of reference numerals

[0129] 1u, 1o substrate holder

[0130] 2, 2u, 2o substrate

[0131] 2r, 2r' side edges

[0132] Room 3

[0133] 4. Drilling

[0134] 5. Material layer

[0135] 7 Fasteners

[0136] 8 Control components

[0137] 9. Optical System

[0138] 10 Connect the starting surface

[0139] 11. Cavity

[0140] 12-room space

[0141] 13 wafers

[0142] 14 Adhesive layer

[0143] 15 films

[0144] 16 Framework

[0145] 17u, 17o contact surfaces

[0146] 18u, 18o mounting surfaces

[0147] v x v y v z speed.

Claims

1. A method for connecting a first substrate (2o) to a second substrate (2u) at contact surfaces (17u, 17o) of a first substrate (2o) and a second substrate (2u), the method comprising the steps of: The first substrate (2o) is mounted on the first mounting surface (18o) of the first substrate holder (1o), and the second substrate (2u) is mounted on the second mounting surface (18u) of the second substrate holder (1u), wherein the substrate holders (1o, 1u) are arranged in a chamber (3). The chamber is evacuated before and / or during the mounting and / or alignment of the substrate. The contact surfaces (17u, 17o) are contacted at the connection starting surface (10), wherein annular contact is performed. The first substrate (2o) is connected to the second substrate (2u) from the connection starting surface (10) to the center of the substrates (2o, 2u), and Increase the chamber pressure in the chamber under the following conditions: (i) After contacting the respective contact surfaces of the first and second substrates at the connection initiation surface, and / or (ii) During the process of connecting the first substrate to the second substrate.

2. The method of claim 1, wherein the connection starting surface (10) is disposed at the outer peripheral edge of at least one of the contact surfaces (17u, 17o).

3. The method of claim 1 or 2, wherein prior to the contact, the first substrate (2o) is concave relative to the second substrate (2u).

4. The method of claim 3, wherein the concave deformation is achieved by mounting the first substrate (2o) on the first mounting surface (18o) corresponding to the concave bend.

5. The method of claim 1 or 2, wherein the connection starting surface (10) is configured to be distributed in a ring-shaped manner.

6. The method of claim 5, wherein the connection initiation surface (10) is peripherally closed.

7. The method of claim 5, wherein the connection starting surface (10) is configured to be distributed in a circular manner.

8. The method of claim 5, wherein the connection initiation surface (10) is configured to be concentrically distributed with the center of the substrate (2u, 2o).

9. The method of claim 1 or 2, wherein the first substrate (2o) and / or the second substrate (2u) are subsequently fixed to the first mounting surface (18o) and / or the second mounting surface (18u) only in the region of the side edge (2r) of the contact surface (17u, 17o).

10. An apparatus for connecting a first substrate (2o) to a second substrate (2u) at contact surfaces (17u, 17o) of a first substrate (2o) and a second substrate (2u), the apparatus comprising: The first mounting surface (18o) of the first substrate holder (1o) is used to mount the first substrate (2o). The second mounting surface (18u) of the second substrate holder (1u) is used to mount the second substrate (2u). Chamber (3), in which the substrate holders (1u, 1o) are arranged, A component for evacuating the chamber before and / or during the mounting and / or alignment of the substrate. A component for contacting the contact surfaces (17u, 17o) at the connection starting surface (10), wherein annular contact is made, and a component for connecting the first substrate (2o) to the second substrate (2u) from the connection starting surface (10) to the center of the substrates (2u, 2o), and A component for increasing the chamber pressure in the following situations: (i) After contacting the respective contact surfaces of the first and second substrates at the connection initiation surface, and / or (ii) During the process of connecting the first substrate to the second substrate.

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