Methods for bonding and debonding substrates

Abstract

To provide a method for bonding a product substrate with a connection layer to a support substrate, and a method for releasing the product substrate from the bonded support substrate.SOLUTION: A release layer (3) is applied between a connection layer (4) and a product substrate (2). a) The release layer (3) can be released by interacting with an electromagnetic radiation of a radiation source, and b) the connection layer (4) and the support substrate (5) are each at least largely transparent to the electromagnetic radiation. The present invention further relates to a corresponding product substrate / support substrate composite.SELECTED DRAWING: Figure 1b

Description

[Technical Field]

[0001] The present invention relates to a method for bonding a product substrate to a carrier substrate by means of a bonding layer according to claim 1, a method for peeling a product substrate from a carrier substrate bonded to the product substrate by means of a bonding layer according to claim 2, and a product substrate-carrier substrate-composite according to claim 9. [Background technology]

[0002] In the prior art, there are several methods for debonding or peeling two substrates (a product substrate and a carrier substrate). Many methods use so-called bonding adhesives to achieve a temporary adhesion that allows for relatively easy peeling of the two substrates. The bonding adhesives are often polymers, especially thermoplasts.

[0003] The first method for forming a temporary bond is to coat the entire surface of the substrate. A second substrate is bonded to the first substrate by a bonding process. Separation, debonding, or peeling of the two substrates is achieved by a shear process at elevated temperatures, preferably above the glass transition temperature of the bonding adhesive. The applied shear force allows the two substrates to slide relative to one another and separate from one another in a fairly slow process.

[0004] The second method for forming a temporary bond involves treating a specific surface area of ​​the carrier substrate so that the adhesive between this surface area and the applied bonding adhesive is minimized, or even completely eliminated. In addition to the specially treated surface area, a very small untreated surface area remains. The highly adhesive surface area is usually a peripheral ring with a thickness of a few millimeters. After this special treatment, the carrier substrate is coated over its entire surface with bonding adhesive. The usual bonding process then takes place. The peeling process is usually carried out chemically by peeling off the edge area of ​​the bonding adhesive, thereby reducing the adhesive force between the bonding adhesive and the carrier substrate. The carrier substrate can then be very easily removed from the product substrate.

[0005] Another method for separating two substrates from each other involves providing a special release layer on a particularly transparent carrier substrate before coating with a bonding adhesive. The transparency of the carrier substrate to certain electromagnetic radiation allows photons to reach the release layer unhindered. The release layer is correspondingly altered by the photons, reducing its adhesive strength to the bonding adhesive. International Publication No. WO2014058601A1 describes such a method, in which an ultraviolet laser is irradiated onto the release layer located inside the carrier substrate to form a reaction in situ that causes the separation of the bonding adhesive from the carrier substrate and, therefore, the separation of the carrier substrate from the product substrate. Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the invention is to provide a method and an apparatus in which an optimum flow is achieved during bonding and during debonding or peeling, and in which subsequent method steps are simplified. [Means for solving the problem]

[0007] This problem is solved by the features of claims 1, 2 and 9. Advantageous embodiments of the invention are set out in the respective dependent claims. Furthermore, all combinations of at least two of the features shown in the description, claims and / or drawings also fall within the scope of the invention. When value ranges are indicated, values ​​within the stated ranges are also disclosed as limit values ​​and may be claimed in any combination.

[0008] The invention is based on the idea of ​​providing a method and an apparatus with which a product substrate-carrier substrate-composite can be produced, in which the product substrate and the carrier substrate are bonded together by a bonding layer that is at least largely transparent to electromagnetic radiation, and a release layer is provided between the bonding layer and the product substrate, which is configured to be debondable by interaction with electromagnetic radiation from a radiation source.

[0009] According to the method of the present invention, during the binding, in particular a) making the release layer releaseable by interaction with electromagnetic radiation from a radiation source; b) making at least a majority of each of the bonding layer and the support substrate transparent to electromagnetic radiation; The following features / steps can be used:

[0010] According to the method of the present invention, during the peeling, in particular a) releasing the release layer (3) by interaction with electromagnetic radiation of a radiation source; b) making at least a majority of each of the bonding layer (4) and the support substrate (5) transparent to electromagnetic radiation; The following features / steps can be used:

[0011] According to the device of the present invention, in particular: a) the release layer (3) is made releaseable by interaction with electromagnetic radiation of a radiation source; b) at least a majority of each of the bonding layer (4) and the support substrate (5) is transparent to electromagnetic radiation; The following features can be used.

[0012] The central idea of ​​the present invention (particularly independently) is to use a bonding adhesive (bonding layer) that has a small absorption coefficient, especially in the wavelength region of the electromagnetic radiation used, especially in the wavelength region of the laser. The absorption coefficient, especially the linear absorption coefficient, is preferably normalized by the mass density. The mass absorption coefficients of various materials obtained in this way can then be compared with each other. Mass absorption coefficients can be obtained for elements and several compounds for X-ray radiation from the NIST X-ray attenuation database (http: / / www.nist.gov / pml / data / xraycoef). Since the mass absorption coefficient depends very strongly on the wavelength, the following wavelength ranges and mass absorption coefficient ranges are shown for several pure elements and several compounds, especially polymers. [Table 1] The value range of the mass absorption coefficient in the NIST X-ray attenuation database is 10 -3 MeV to 10 2 The definition of the MeV megaelectron volt range is shown in the figure. The ultraviolet range is 10 -5 Since the mass absorption coefficient is in the MeV definition range, it is not possible to directly read the mass absorption coefficient in the ultraviolet range from this definition range. In addition, the publication US Pat. No. 5,965,065 (US5,965,065A) shows the value range of the mass absorption coefficient for the desired elements in the ultraviolet range, namely, carbon, nitrogen, and oxygen. Carbon, in particular, is the main component of organic polymers. However, even if the mass absorption coefficient of a compound cannot be automatically derived from the mass absorption coefficients of the pure components, it is possible to at least estimate the value range of the mass absorption coefficient of the compound. From all of this data, the mass absorption coefficient for the compound of the present invention is 10 -6 ~10 2 Approximately 10 in the defined energy range of MeV -2 ~10 5 cm 2 / g, which is a range of values ​​of 10 to the power of 7. The publication US Pat. No. 5,965,065 (US5,965,065A) states that the mass absorption coefficient for carbon varies between 1000 cm and 1000 cm in a range of powers of 10. 2 / g to 10 6 cm 2 It is also shown that the mass absorption coefficient changes from 1000 eV to 100 eV between 1000 eV and 1000 eV / g. Furthermore, it is understood that the absorption edge for carbon is at about 300 eV. From all the data, it can be seen that small changes in energy or wavelength region can cause large changes in the absorption characteristics of a material. Therefore, it is not possible or meaningful to provide individual values ​​of the mass absorption coefficient for all possible materials, particularly for the present invention.

[0013] Thus, in the present invention, the release layer can be formed on the product substrate rather than the carrier substrate, and the low absorption of electromagnetic radiation by the bonding adhesive allows enough photons to reach the release layer to initiate the release or debonding process at that location.

[0014] Furthermore, the present invention relates to a system and method for debonding or peeling two substrates using an electromagnetic photon source, in particular a laser, where the invention is based in particular on the idea of ​​introducing, in particular focusing, electromagnetic radiation into a release layer in order to reduce the adhesion between the product substrate and the carrier substrate, the electromagnetic radiation being transmitted through the bonding adhesive that bonds the two substrates together, in particular without heating it.

[0015] The idea of ​​the present invention is therefore to use, inter alia, a specially tailored combination of bonding adhesive, electromagnetic radiation and release layer.

[0016] The advantages of the present invention include, inter alia, that a release layer can be provided on the product substrate, which is thus positioned between the product substrate and the bonding layer. Irradiating the release layer with electromagnetic radiation, in particular with a laser, reduces the adhesive force, allowing the product substrate to be directly separated from the bonding adhesive, particularly automatically. Therefore, the product substrate is preferably already free from the bonding adhesive immediately after the separation, and no additional chemical cleaning is required.

[0017] The release layer is preferably configured to be completely destroyed, particularly sublimated, during the damaging process of the present invention.

[0018] Electromagnetic radiation interacts with the electrons of materials. This interaction occurs because alternating electromagnetic fields can cause electrically charged electrons to vibrate. Positively charged nuclei have a much larger mass and therefore a greater inertia relative to the electrons. Therefore, the motion of the nuclei is often ignored.

[0019] Depending on the frequency, an alternating electromagnetic field can produce various physical effects in solids, particularly molecules. Since the concept of the present invention is primarily related to polymers, the physical effects will be described below in particular with respect to molecules, particularly polymers.

[0020] Under certain conditions, molecules or molecular parts can absorb photons and convert the photon energy into vibrational energy, rotational energy, and / or potential energy. To enable this energy conversion, the photons must have a certain frequency. The new energy state that is formed can be reduced again by the emission of a photon with the appropriate wavelength. This steady absorption and emission of photons, the resulting energy conversion, and the distribution of energy to the individual degrees of freedom of the molecule involve statistical processes, which will not be discussed further here.

[0021] Electromagnetic radiation in the microwave and infrared regions primarily excites rotations in molecules.

[0022] Electromagnetic radiation in the infrared range preferably causes molecules to vibrate. Two types of vibrations are distinguished: Barents vibrations and deformation vibrations. The first type of vibration is one in which two atoms of a molecule vibrate along a bond axis, while the second type of vibration is one in which a change in bond angle generates vibrations between at least three atoms of a molecule.

[0023] Photons of electromagnetic radiation in the ultraviolet wavelength range already have enough energy to either elevate individual electrons in a molecular structure to higher molecular orbitals or even dissociate electrons from the molecular structure, thereby ionizing the molecule. The excited electrons are typically valence electrons, i.e., electrons located in the outermost molecular orbitals. Separating nuclear electrons requires significantly greater photon energy, especially in the x-ray wavelength range. Transmittance is greatest in wavelength regions where excitation of electrons from the highest occupied molecular orbital (HOMO) to the lowest occupied molecular orbital (LUMO) is not possible. Because photons cannot interact with electrons and electron transitions from the HOMO to the LUMO are precluded, photons pass unimpeded through solids, particularly polymers, and most preferably bonding adhesives.

[0024] Thus, molecular orbital theory already provides hints for the possible chemical synthesis of the bonding adhesive of the present invention.

[0025] Radiation sources, especially photon sources According to the invention, in particular a photon source is used as the radiation source.

[0026] The source is therefore in particular a photon source, at least in large part, preferably exclusively. Microwave, 300mm~1mm, Infrared, especially ·Near infrared, 0.78μm~3.0μm, ·Mid-infrared, 3.0μm~50μm, ·Far infrared rays, 50μm~1000μm, ·Visible light, 380nm~780nm, UV rays, especially ·Near UV, 360nm~315nm, ·Medium UV, 315nm~280nm, ·Deep ultraviolet rays, 280nm~200nm, ·Vacuum ultraviolet light, 200nm~100nm, ·Extreme ultraviolet rays, 121nm~10nm, ·X-ray, 0.25nm~0.001nm, The radiation is emitted in one or more of the wavelength ranges of 1000 μm to 10 nm, preferably 780 nm to 100 nm, and most preferably 370 nm to 200 nm.

[0027] It is also possible to use a source capable of generating two different wavelength ranges. In this case, all of the above-mentioned prerequisites of the present invention for all individual wavelengths apply. A combination of ultraviolet and infrared light is particularly preferred. The infrared light is primarily used to heat the release layer, and the ultraviolet light is primarily used to break the covalent bonds. In such a combination, the bonding adhesive of the present invention must have low absorption in both wavelength ranges.

[0028] According to the invention, preference is given to lasers configured at least predominantly, preferably exclusively, as coherent photon sources, in particular microwave sources, preferably masers, or as coherent photon sources for visible light, ultraviolet light and X-rays.

[0029] The photon source can be operated in continuous wave mode or (preferably) in pulsed mode. The pulse duration is in particular less than 1 s, preferably less than 1 ms, even more preferably less than 1 μs, most preferably less than 1 ns. The time between two successive pulses is preferably more than 1 ms, even more preferably more than 100 ms, most preferably more than 1 s.

[0030] The wavelength of the photon source is in particular selected so that the photon stream can be at least largely, preferably completely, transmitted through the bonding layer, in particular the bonding adhesive, without significant losses due to absorption.

[0031] The photon absorption rate of the bonding layer is particularly less than 50%, preferably less than 25%, more preferably less than 10%, most preferably less than 1%, and most preferably less than 0.1%. Thus, the photon transmission rate of the bonding layer is particularly greater than 50%, preferably greater than 75%, more preferably greater than 90%, most preferably greater than 99%, and most preferably greater than 99.9%. The absorption rate is related to the layer thickness, which is selected based on the material properties and the requirements for the product wafer.

[0032] In particular, the properties of the bonding layer and the photon source or electromagnetic radiation are selected and / or configured (especially by appropriate material selection) so that the bonding layer is not significantly heated. Heating is especially below 50°C, preferably below 25°C, more preferably below 10°C, most preferably below 1°C, and most preferably below 0.1°C. Heating can be largely eliminated, especially by using a photon source with an electromagnetic wavelength range that does not excite vibrational or rotational degrees of freedom of the molecules of the bonding layer. To prevent heating, preferably an electromagnetic beam in the ultraviolet-visible wavelength range is used in combination with a bonding layer that is ultraviolet-visible transparent.

[0033] In the following, a laser will be described as a preferred embodiment of the radiation source of the present invention, in particular the electromagnetic photon source, although the radiation sources mentioned above may be used instead of a laser.

[0034] Quantitative analysis of the transmittance of solids, particularly polymers, preferably the bonding layers of the present invention, is performed by UV-Vis spectroscopy, which is a graph showing the transmittance of photons of a particular wavelength as a function of wavelength.

[0035] Support substrate In a preferred embodiment, the transmittance of the carrier substrate for the wavelength of the used laser (electromagnetic radiation of the invention) is of decisive importance. According to the invention, the laser beam is input through the carrier substrate into the substrate stack (product substrate - carrier substrate - composite). This means that the product substrate may be opaque to the wavelength of the laser, in particular in the area of ​​the provided functional units (metal units) and / or at least the majority of the raised structures. The carrier substrate is therefore preferably selected from a material that attenuates the intensity of the laser beam as little as possible. The carrier substrate is in particular mainly, preferably completely, Glass, Minerals, especially sapphires, Semiconductor materials, especially silicon, ·polymer, ·Compound materials, According to the invention, a carrier substrate is preferably used which is made of glass.

[0036] The thickness of the carrier substrate is selected in particular to be large enough to ensure stabilization of the product substrate (especially together with the bonding layer), and is in particular greater than 100 μm, preferably greater than 500 μm, even more preferably greater than 1000 μm, most preferably greater than 1500 μm, and most particularly preferably greater than 2000 μm.

[0037] At the same time, the thickness is selected to be the minimum necessary to minimize attenuation of the intensity of the laser beam. The thickness of the carrier substrate is in particular less than 2000 μm, preferably less than 1750 μm, even more preferably less than 1500 μm, most preferably less than 1250 μm, and most preferably less than 900 μm.

[0038] Tie layers, especially bonding adhesives As a bonding adhesive, especially Polymers, especially Inorganic polymers, preferably Polyphosphazene, Polysiloxane, silicone, Polysilanes, Organic polymers, especially Acrylate ester-styrene-acrylonitrile, Acrylonitrile / methyl methacrylate, Acrylonitrile / butadiene / acrylate, Acrylonitrile / chlorinated polyethylene / styrene, Acrylonitrile-butadiene-styrene, Acrylic polymers, Alkyd resins, Butadiene rubber, Butyl rubber, Casein plastic, Galalith, Cellulose acetate, Cellulose ethers and derivatives, hydrated cellulose, Nitrocellulose, Chitin, chitosan, Chloroprene rubber, Cycloolefin copolymers, Standardized polyvinyl chloride, Epoxy resin, Ethylene-ethyl acrylate copolymer, Ethylene-polyvinyl acetate, ethylene-propylene copolymers, Ethylene-propylene-diene-rubber, Ethylene vinyl acetate, Expanded polystyrene, Fluorine rubber, Urea formaldehyde resin, ·Urea resin, Isoprene rubber, Lignin, Melamine formaldehyde resin, Melamine resin, Methyl acrylate / butadiene / styrene, Natural rubber, Perfluoroalkoxyalkanes, Phenol formaldehyde resin, Polyacetal, Polyacrylonitrile, ·polyamide, Polybutylene succinate, Polybutylene terephthalate, Polycaprolactone, Polycarbonate, Polychlorotrifluoroethylene, ·polyester, Polyesteramide, Polyether alcohols, Polyether block amides, Polyetherimide, Polyetherketone, Polyethersulfone, ·polyethylene, Polyethylene terephthalate, Polyhydroxyalkanoates, Polyhydroxybutyrate, Polyimide, Polyisobutylene, Polylactide (polylactic acid), Polymethacrylmethylimide, Polymethyl methacrylate, Polymethylpentene, Polyoxymethylene or polyacetal, Polyphenylene ether, Polyphenylene sulfide, Polyphthalamide, ·polypropylene, Polypropylene copolymer, Polypyrrole, ·polystyrene, Polysulfone, Polytetrafluoroethylene, Polytrimethylene terephthalate, Polyurethane, Polyvinyl acetate, Polyvinyl butyral, Polyvinyl chloride (rigid PVC), Polyvinyl chloride (soft PVC), Polyvinylidene fluoride, Polyvinylpyrrolidone, Styrene-acrylonitrile copolymer, Styrene-butadiene rubber, Styrene-butadiene-styrene Synthetic rubber, Thermoplastic polyurethane, Unsaturated polyester, vinyl acetate copolymer, Vinyl chloride / ethylene / methacrylate, Vinyl chloride / ethylene, vinyl chloride-vinyl acetate copolymer, Plasticized polyvinyl chloride, The material is selected from one or more of the above.

[0039] In particular, inorganic polymers such as silicones are preferably used as bonding adhesives according to the present invention, since they have a relatively high transmittance for the broad wavelength range of the lasers preferred as radiation sources of the present invention.

[0040] The bonding adhesive is preferably applied by the following process steps: in a first process step, the application of the bonding adhesive is carried out by a spin-coating process; in a second process step, a heat treatment is carried out to drive off any solvents; the temperature of this heat treatment is in particular above 50°C, preferably above 75°C, more preferably above 100°C, most preferably above 100°C, particularly most preferably above 150°C; preferably the temperature of the heat treatment is below 500°C.

[0041] peeling layer The release layer can be made of any material that is capable of reducing the adhesive strength of at least one side of the release layer, preferably the side facing the product substrate, under the action of the electromagnetic radiation described above. The release layer of the present invention is completely sublimated, particularly using electromagnetic radiation.

[0042] The release layer can be formed as a laminate film, particularly in embodiments of the present invention.

[0043] The release layer of the present invention is preferably formed or applied as a molecular layer, in particular as a monolayer, and in particular has a layer thickness of less than 100 μm, preferably less than 50 μm, more preferably less than 10 μm, most preferably less than 500 nm, and most preferably less than 1 nm.

[0044] The physical and / or chemical properties of the release layer with respect to electromagnetic radiation are selected (especially by material selection) and / or adjusted (especially by adjusting parameters such as pressure, humidity, temperature, etc.) to be particularly at least partially, preferably largely, and even more preferably completely complementary to the corresponding physical and / or chemical properties of the bonding layer and / or the carrier substrate. The acting electromagnetic radiation is particularly absorbed, at least largely, and preferably completely, by the release layer of the present invention.

[0045] The absorption of electromagnetic radiation, especially photons, by the release layer of the present invention is particularly greater than 50%, preferably greater than 75%, more preferably greater than 90%, most preferably greater than 99%, and most preferably greater than 99.9%. Accordingly, the transmittance is less than 50%, preferably less than 25%, more preferably less than 10%, most preferably less than 1%, and most preferably less than 0.1%. Again, the absorption value is related to the layer thickness, which is selected based on the material properties and the requirements for the product wafer.

[0046] Preferably, the material of the release layer and the electromagnetic radiation are selected so that the interaction of the electromagnetic radiation with the release layer excites as many rotational and / or vibrational degrees of freedom as possible and / or transfers electrons from the highest occupied molecular orbital to the lowest occupied molecular orbital. Preferably, this interaction occurs, in particular exclusively, in the ultraviolet-visible spectrum. Therefore, in particular, only a direct effect on the electronic structure occurs, preferably without exciting rotational and / or vibrational degrees of freedom. That is, the excitation of rotational and / or vibrational degrees of freedom leads to heating of the release layer of the present invention and, therefore, to heating of the product substrate in contact therewith.

[0047] The material of the release layer and the electromagnetic radiation are selected in particular so that the temperature rise of the release layer upon interaction with the electromagnetic radiation is less than 50° C., preferably less than 25° C., more preferably less than 10° C., most preferably less than 1° C., and most preferably less than 0.1° C. This heating can be largely eliminated, in particular by using a photon source with an electromagnetic wavelength range that does not excite vibrational or rotational degrees of freedom. Therefore, in order to prevent heating, electromagnetic beams in the ultraviolet-visible wavelength range are used in accordance with the invention.

[0048] Suitable heating of the release layer may be desirable according to the present invention, as high thermal momentum promotes dissolution of the release layer of the present invention, preferably by at least 0.1°C, more preferably by at least 1°C, more preferably by at least 5°C, and more preferably by at least 10°C.

[0049] As a release layer, in particular Polymers, especially Organic polymers, especially Acrylate ester-styrene-acrylonitrile, Acrylonitrile / methyl methacrylate, Acrylonitrile / butadiene / acrylate, Acrylonitrile / chlorinated polyethylene / styrene, Acrylonitrile-butadiene-styrene, Acrylic polymers, Alkyd resins, Butadiene rubber, Butyl rubber, Casein plastic, Galalith, Cellulose acetate, Cellulose ethers and derivatives, hydrated cellulose, Nitrocellulose, Chitin, chitosan, Chloroprene rubber, Cycloolefin copolymers, Standardized polyvinyl chloride, Epoxy resin, Ethylene-ethyl acrylate copolymer, Ethylene-polyvinyl acetate, ethylene-propylene copolymers, Ethylene-propylene-diene-rubber, Ethylene vinyl acetate, Expanded polystyrene, Fluorine rubber, Urea formaldehyde resin, ·Urea resin, Isoprene rubber, Lignin, Melamine formaldehyde resin, Melamine resin, Methyl acrylate / butadiene / styrene, Natural rubber, Perfluoroalkoxyalkanes, Phenol formaldehyde resin, Polyacetal Polyacrylonitrile, ·polyamide, Polybutylene succinate, Polybutylene terephthalate, Polycaprolactone, Polycarbonate, Polycarbonate, Polychlorotrifluoroethylene, ·polyester, Polyesteramide, Polyether alcohols, Polyether block amides, Polyetherimide, Polyetherketone, Polyethersulfone, ·polyethylene, Polyethylene terephthalate, Polyhydroxyalkanoates, Polyhydroxybutyrate, Polyimide, Polyisobutylene, Polylactide (polylactic acid), Polymethacrylmethylimide, Polymethyl methacrylate, Polymethylpentene, Polyoxymethylene or polyacetal, Polyphenylene ether, Polyphenylene sulfide, Polyphthalamide, ·polypropylene, Polypropylene copolymer, Polypyrrole, ·polystyrene, Polysulfone, Polytetrafluoroethylene, Polytrimethylene terephthalate, Polyurethane, Polyvinyl acetate, Polyvinyl butyral, Polyvinyl chloride (rigid PVC), Polyvinyl chloride (soft PVC), Polyvinylidene fluoride, Polyvinylpyrrolidone, Styrene-acrylonitrile copolymer, Styrene-butadiene rubber, Styrene-butadiene-styrene, Synthetic rubber, Thermoplastic polyurethane, Unsaturated polyester, vinyl acetate copolymer, Vinyl chloride / ethylene / methacrylate, Vinyl chloride / ethylene, vinyl chloride-vinyl acetate copolymer, Plasticized polyvinyl chloride, Inorganic polymers, Polyphosphazene, Polysiloxane, silicone, Polysilanes, ·Metals, especially Cu,Ag,Au,Al,Fe,Ni,Co,Pt,W,Cr,Pb,Ti,Ta,Zn,Sn, Metal alloys, ·Nonmetals, ·ceramic, Glass, Metallic glasses, Non-metallic glasses, especially Organic non-metallic glasses, Inorganic non-metallic glasses, especially Non-oxide glasses, especially Halide glasses, Chalcogenide glasses, Oxide glasses, especially Phosphate glass, silicate glasses, especially Alumosilicate glass, Lead silicate glass, Alkali silicate glasses, especially Alkali-alkaline earth silicate glasses, Borosilicate glass, Borate glasses, especially alkali borate glasses, Each material is treated.

[0050] According to the present invention, a release layer made of a polymer is preferably used. Polymers are particularly suitable as release layers due to their numerous bond types, especially σ-bonds, π-bonds, and mesomeric stabilizing aromatic bonds (benzene rings). These bonds result in a highly complex UV-visible spectrum, providing wavelength regions that allow for resonant interactions between incident photons and electrons.

[0051] Metals and metal alloys have the absorption spectrum of crystalline solids and are particularly suitable as release layers because they can be heated by photon excitation.

[0052] Ceramics and glasses have minimal interaction effects: they are mostly amorphous or at least partially amorphous.

[0053] The release layer is preferably formed by the following process steps.

[0054] In a first process step, the formation of the release layer is performed by a spin coating process.

[0055] The second process step involves a heat treatment to drive off any solvent, in particular at a temperature above 50°C, preferably above 75°C, more preferably above 100°C, most preferably above 100°C, and most preferably above 150°C. Preferably, the temperature of the heat treatment is below 500°C.

[0056] In the third process step, a second heat treatment is carried out at a higher temperature to harden the release layer, in particular at a temperature above 100°C, preferably above 150°C, more preferably above 200°C, most preferably above 250°C, and most preferably above 300°C. Curing can also be carried out by electromagnetic radiation, in particular ultraviolet light. Chemical complete curing using process gases is also possible. Curing can also be carried out, in particular by air moisture.

[0057] In a first embodiment of the present invention, a substrate laminate (product substrate-support substrate-composite) is formed from a product substrate, a release layer of the present invention provided on the product substrate, particularly over the entire surface, a bonding adhesive (bonding layer), and a support substrate.

[0058] In this case, the surface of the product substrate does not have to be flat, and it is also possible for the surface of the product substrate to have functional units with raised structures that are also coated.

[0059] According to the invention, the production of such a substrate stack is carried out in particular by one or more of the process steps described below.

[0060] In the first process step of the present invention, the release layer of the present invention is coated on the product substrate, particularly over the entire surface. The coating of the release layer of the present invention can be performed (preferably) by spin coating, spray coating, or blade coating. When the release layer of the present invention is a film, it is preferably laminated.

[0061] The second process step of the present invention involves the application of a bonding adhesive (bonding layer). The bonding adhesive can therefore be applied onto the release layer of the present invention, onto the product substrate and / or onto the carrier substrate.

[0062] The third process step of the present invention involves bonding the two substrates together, in particular by bonding under pressure, which may be preceded by an alignment process.

[0063] In a second embodiment of the present invention, a substrate laminate (product substrate-support substrate-composite) is formed from a product substrate, an anti-adhesion layer provided in the center of the product substrate, a release layer of the present invention provided on the periphery, a bonding adhesive (bonding layer), and a support substrate.

[0064] According to the invention, the production of such a substrate stack is carried out in particular by one or more of the process steps described below.

[0065] In the first process step of the present invention, the product substrate is concentrically coated with an anti-adhesion layer. The anti-adhesion layer can be applied by spin coating or spray coating. The anti-adhesion layer is not applied over the entire surface. In particular, a peripheral ring portion is left uncoated with a ring width of less than 10 mm, preferably less than 5 mm, more preferably less than 3 mm, most preferably less than 2 mm, and most preferably less than 1 mm. To obtain such a central coating with an uncoated peripheral ring portion, the product substrate is masked in the area of ​​the peripheral ring portion.

[0066] In the second process step of the present invention, the release layer of the present invention is coated on the peripheral ring portion of the product substrate.The release layer of the present invention can be coated by spin coating, spray coating or blade coating.When the release layer of the present invention is a film, the film is preferably laminated in the peripheral region.It is also possible to laminate the entire surface and remove the central portion of the film.

[0067] The third process step of the present invention involves the application of a bonding adhesive, which can be applied onto the release layer of the present invention and thus onto the product substrate and / or onto the carrier substrate.

[0068] The fourth process step of the present invention involves bonding the two substrates together, in particular by bonding them under pressure, which may be preceded by an alignment process.

[0069] The release layer of the present invention can be acted on (especially by the action of electromagnetic radiation) either concentrically towards the periphery through the support or only laterally. The release layer of the substrate stack can also be acted on by the systems mentioned in the publication PCT European Patent Application Publication No. 2015 / 050607 (PCT / EP2015 / 050607).

[0070] In a third embodiment of the present invention, a substrate stack is formed from a product substrate, a bonding adhesive, a central anti-adhesion layer on the carrier substrate, and a peripheral release layer of the present invention. This embodiment is an extension of patent document U.S. Patent Application Publication No. 20090218560 A1.

[0071] Peeling process Prior to the peeling process of the present invention, the product substrate is preferably secured to a film spread over a film frame. The film frame and film stabilize the relatively thin product substrate after the carrier substrate is removed. The carrier substrate is preferably removed only after the product substrate is attached to the film in the film frame.

[0072] The peeling process is preferably carried out by means of a laser, which acts on the release layer and thereby reduces the adhesive strength / adhesion between the product substrate and the bonding layer in the first embodiment of the invention or between the carrier substrate and the bonding adhesive in the third embodiment of the invention, in particular by more than 50%, preferably more than 75%, and even more preferably more than 90%.

[0073] The delamination of the substrate stacks of the second and third embodiments of the present invention can be carried out in particular by the system described in publication PCT European Patent Application Publication No. 2015 / 050607 (PCT / EP2015 / 050607).

[0074] After the release process, the surface of the product substrate is preferably cleaned. Another important aspect of the present invention is that the release layer of the first embodiment of the present invention is completely removed, leaving a product substrate with a relatively clean surface that can be cleaned quickly and therefore cost-effectively.

[0075] Where a method feature is disclosed, it is also assumed that an apparatus feature is disclosed, and conversely, where an apparatus feature is disclosed, it is also assumed that a method feature is disclosed.

[0076] Further advantages, features and details of the invention can be obtained from the following description of preferred embodiments in conjunction with the drawings. [Brief explanation of the drawings]

[0077] [Figure 1a] 1 is a schematic, not-to-scale, view of a first embodiment of a product substrate-support substrate-composite of the present invention; [Figure 1b] 1b is a schematic, not-to-scale, illustration of one embodiment of a method of the present invention for delaminating the product substrate-carrier substrate-composite of FIG. 1a. [Figure 2a] 2 is a schematic, not-to-scale, view of a second embodiment of a product substrate-support substrate-composite of the present invention; FIG. [Figure 2b] 2b is a schematic, not-to-scale, illustration of one embodiment of a method of the present invention for delaminating the product substrate-carrier substrate-composite of FIG. 2a. [Figure 3] 1 is a schematic, not-to-scale, view of a third embodiment of a product substrate-support substrate-composite of the present invention; [Figure 4] FIG. 1 is a schematic, not to scale, diagram showing a first absorptance graph (absorbance = absorptance). [Figure 5]FIG. 1 is a schematic, not to scale, diagram showing a second absorbance graph (absorbance = absorbance). DETAILED DESCRIPTION OF THE INVENTION

[0078] In the figures, the same elements or elements with similar functions are given the same reference numerals.

[0079] All of the illustrated product substrates 2 can be provided with functional units 6. However, product substrates without corresponding functional units 6 are also possible. The functional units 6 can be, for example, microchips, memory modules, MEMS devices, etc. The functional units 6 can also be provided with raised structures 7, for example solder bumps. These raised structures 7 can be shaped differently, but can make coating with the release layer 3 correspondingly difficult and / or incomplete. Therefore, any reference to coating the product substrate 2 also includes a reference to coating the functional units 6 and / or raised structures 7.

[0080] 1a shows, diagrammatically and not to scale, a first embodiment of the inventive substrate stack 1, which is formed from at least one product substrate 2, a release layer 3, a bonding adhesive as a bonding layer 4 and a carrier substrate 5. Above the topography of the provided product substrate 2 with (possible) functional units 6 and raised structures 7, the inventive release layer 3 is applied, in particular over the entire surface. The release layer surface 3o is in contact with the bonding adhesive, which is further bonded to the carrier substrate 5.

[0081] 1b shows a schematic, not to scale, illustration of the release process of the present invention. A laser 9 generates a laser beam 10 which is incident on the bonding adhesive through the carrier substrate 5. According to the present invention, the absorption of the bonding adhesive is minimized by balancing the wavelength of the laser beam 10 according to the present invention. The laser beam 10 is therefore incident on the release layer 3 with, in particular, minimal, and preferably negligible, energy loss.

[0082] According to the present invention, the interaction of the photons of the laser beam 10 with the release layer 3 is significantly greater, preferably maximal, than the interaction with the bonding adhesive. The release layer 3 is at least partially, preferably largely, and more preferably completely dissolved or destroyed. At the very least, the adhesion strength between the product substrate 2 and the bonding adhesive is reduced.

[0083] The laser 9 scans, in particular, over the release layer surface 3o by movement in the x- and / or y-direction, and may also be adjusted in the z-direction to ensure good focusing if the laser beam 10 cannot be optimally collimated.

[0084] 2a shows, diagrammatically and not to scale, a second embodiment of the inventive substrate stack 1', which is formed from at least one product substrate 2, a release layer 3 only on the periphery of the product substrate 2, an anti-adhesion layer 8 in the center of the product substrate 2, a bonding layer 4 formed as a bonding adhesive, and a carrier substrate 5. The adhesive effects between the anti-adhesion layer 8 and the bonding adhesive are minimized according to the invention, whereas a relatively high (at least twice as high) adhesive strength is achieved between the inventive release layer 3 and the bonding adhesive.

[0085] Figure 2b shows the dissolution of the release layer 3 of the second embodiment of the invention of Figure 2a. The laser beam 10 is preferably focused only on the periphery of the substrate stack 1'. Preferably, the system is configured such that the laser 9 is stationary and the substrate stack 1' rotates about a rotation axis R.

[0086] Figure 3 shows, not to scale, a schematic representation of a third embodiment of the substrate stack 1'' of the present invention, which is formed from at least one product substrate 2, a bonding layer 4 formed as a bonding adhesive, a release layer 3 provided only on the periphery of the carrier substrate 5, an anti-adhesion layer 8 provided in the center of the carrier substrate 5, and a carrier substrate 5.

[0087] A release layer 3 is provided on the periphery of the carrier substrate 5, where the release layer 3 is sensitive to the wavelength of the used laser beam 10. The release process can be performed by the configuration of the embodiment of the present invention in FIG. 2b or by the system of the published PCT European Patent Application No. PCT / EP2015 / 050607.

[0088] 4 shows an absorptance graph 11 of a portion of the absorption spectrum of the bonding adhesive, in particular the UV-visible absorption spectrum. The absorptance graph 11 preferably has at least one, in particular three or more, even more preferably four or more, most preferably five or more, and most preferably six or more local absorptance minima 12.

[0089] For the sake of clarity, only one central local absorptance minimum 12 is shown in the absorptance graph 11. The local absorptance minimum 12 is part of an optimum absorptance region 13, to which the wavelength of the laser beam 10 of the laser 9 used in the present invention is adapted.

[0090] According to the invention, the bonding adhesive used is selected so that the wavelength of the laser beam 10 used lies within the optimum absorption region 13, preferably exactly at the absorption minimum 12. In this way, the maximum transmission of the bonding adhesive for the laser beam 10 according to the invention is guaranteed.

[0091] 5 shows an absorptance graph 11' of a portion of the absorption spectrum of the release layer 3. The absorption spectrum is particularly an ultraviolet-visible absorption spectrum. The absorptance graph 11' preferably has at least one, particularly three or more, even more preferably four or more, most preferably five or more, and particularly most preferably six or more local absorptance maxima 14. For ease of viewing, only two local absorptance maxima 14 are shown in the absorptance graph 11'.

[0092] The local absorptance maximum 14 is part of an optimal absorptance region 13' to which the wavelength of the laser beam 10 of the laser 9 used in the invention is adapted. According to the invention, the release layer 3 used is selected so that the wavelength of the laser beam 10 used lies within the optimal absorptance region 13', preferably exactly at the absorptance maximum 14. In this way, the maximum absorptance of the laser beam 10 according to the invention by the release layer 3 is guaranteed.

[0093] According to the invention, it is of crucial importance, inter alia, that the laser beam 10 penetrates the release layer 3 to a significant extent throughout. If the wavelengths of the laser beam 10, the bonding adhesive 4 and the release layer 3 cannot be optimally adjusted to one another, preferably at least the wavelength of the laser beam 10 is adapted to one or more absorption minima of the bonding adhesive in order to allow the photons of the laser beam 10 to reach the release layer 3 at least as unhindered as possible. [Explanation of symbols]

[0094] 1,1',1'' Substrate stack (product substrate - support substrate - composite) 2 Product board 3 Peeling layer 3o Peeling layer surface 4 Bonding layer 5 Support substrate 5o Support substrate surface 6 Functional Units 7 Raised structure 8 Anti-adhesion layer 8o Anti-adhesion layer surface 9. Laser 10 Laser Beam 11 Absorption rate graph 12 Absorption minimum 13 Optimal absorption rate region 14 Absorption Maximum 15 Dissolved peeling layer R rotation axis

Claims

1. A method for bonding a product substrate (2) to a carrier substrate (5) by means of a bonding layer (4), comprising the steps of: A release layer (3) is provided on the product substrate (2), The bonding layer (4) is provided so that the release layer (3) is disposed between the bonding layer (4) and the product substrate (2); a) making said release layer (3) peelable by interaction with the electromagnetic radiation of a laser; b) the bonding layer (4) and the carrier substrate (5) are each transparent to the electromagnetic radiation; The laser is operable in a pulsed mode. method.

2. A method for peeling a product substrate (2) from a carrier substrate (5) bonded to said product substrate (2) by a bonding layer (4), comprising: A release layer (3) is provided on the product substrate (2), The bonding layer (4) is provided so that the release layer (3) is disposed between the bonding layer (4) and the product substrate (2); a) said release layer (3) is released by interaction with the electromagnetic radiation of a laser, b) the bonding layer (4) and the carrier substrate (5) are each transparent to the electromagnetic radiation; The laser is operable in a pulsed mode. method.

3. selecting the physical and / or chemical properties of the release layer in response to the electromagnetic radiation to be complementary to the corresponding physical and / or chemical properties of the bonding layer (4) and / or the carrier substrate (5); 3. The method according to claim 1 or 2.

4. the photon absorption rate of the electromagnetic radiation in the bonding layer (4) is less than 50%; 4. The method according to any one of claims 1 to 3.

5. the photon absorption rate of the electromagnetic radiation in the release layer (3) is greater than 50%; 5. The method according to any one of claims 1 to 4.

6. The bonding layer (4) is heated to less than 50°C during the peeling process.

6. The method according to any one of claims 1 to 5.

7. The release layer (3) is sublimated by the electromagnetic radiation.

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

8. The release layer (3) is formed or applied with a layer thickness of less than 10 μm.

8. The method according to any one of claims 1 to 7.

9. A product substrate-support substrate-composite comprising a product substrate (2) bonded to a support substrate (5) by a bonding layer (4), A release layer (3) is provided between the bonding layer (4) and the product substrate (2), The release layer (3) is provided directly on the product substrate (2), a) said release layer (3) is made peelable by interaction with the electromagnetic radiation of a laser; b) the bonding layer (4) and the carrier substrate (5) are each transparent to electromagnetic radiation transmitted through the bonding layer (4); The laser is operable in a pulsed mode. Product substrate-support substrate-composite.

Images