CARRIER SUBSTRATE, METHOD FOR PRODUCING A CARRIER SUBSTRATE, AND METHOD FOR TRANSFERRING A TRANSFER LAYER FROM A CARRIER SUBSTRATE TO A PRODUCT SUBSTRATE

Abstract

The invention relates to a carrier substrate for transferring a transfer layer from the carrier substrate onto a product substrate and a method for the production of a carrier substrate and a method for transferring a transfer layer from a carrier substrate onto a product substrate.

Claims

1.-15. (canceled)

16. A carrier substrate for transferring a transfer layer from the carrier substrate to a product substrate, comprising: a plurality of layers, the layers comprising, in sequence: a carrier base substrate; a protective layer; and the transfer layer, wherein at least one release layer is arranged between the carrier base substrate and the protective layer, wherein the transfer layer is grown on the protective layer, and wherein the protective layer shields the transfer layer.

17. The carrier substrate according to claim 16, wherein the transfer layer is a graphene layer.

18. The carrier substrate according to claim 16, wherein a roughness of the protective layer on a surface facing the transfer layer is less than 100 μm.

19. The carrier substrate according to claim 16, wherein the transfer layer comprises at least one release layer arranged between the carrier base substrate and the protective layer.

20. The carrier substrate according to claim 19, wherein the transfer layer is detachable from the carrier base substrate together with the protective layer by means of a debonding means acting on one or more of the release layer and a release area.

21. The carrier substrate according to claim 16, wherein the protective layer comprises a material with a solubility for carbon.

22. The carrier substrate according to claim 16, wherein the protective layer is impermeable to electromagnetic radiation.

23. The carrier substrate according to claim 16, wherein a contact layer made of a dielectric material is arranged on a side of the transfer layer facing away from the protective layer.

24. The carrier substrate according to claim 16, wherein the protective layer is a monocrystalline metal layer.

25. A method for the production of a carrier substrate for transferring a transfer layer from the carrier substrate onto a product substrate, comprising: providing a carrier base substrate; applying a protective layer on the carrier base substrate; and growing the transfer layer on the protective layer.

26. The method according to claim 25, wherein the protective layer is recrystallised before the growing of the transfer layer.

27. The method according to claim 25, wherein the carrier base substrate is coated with a release layer before the applying of the protective layer so that the protective layer is applied on the release layer.

28. The method according to claim 25, wherein a contact layer is deposited on the transfer layer on a side of the transfer layer facing away from the protective layer.

29. The method according to claim 25, wherein the carrier substrate is contacted by the product substrate, so that the transfer layer is facing the product substrate, and wherein at least one debonding means acts on the carrier substrate, so that the transfer layer together with the protective layer is detached from a carrier base substrate.

30. The method according to claim 28, wherein the carrier substrate is contacted by the product substrate via a contact layer applied on the transfer layer.

31. The method according to claim 29, wherein the carrier substrate is contacted by a further contact layer of the product substrate applied on a product base substrate via the contact layer applied on the transfer layer.

32. The carrier substrate according to claim 18, wherein the roughness of the protective layer on the surface facing the transfer layer is less than 10 μm.

33. The carrier substrate according to claim 31, wherein the roughness of the protective layer on the surface facing the transfer layer is less than 1 μm.

34. The carrier substrate according to claim 24, wherein the monocrystalline metal layer is made of nickel.

35. The method according to claim 25, wherein the transfer layer is a graphene layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0172] Further advantages, features and details of the invention emerge from the following description of preferred examples of embodiment and with the aid of the drawings, In the figures, diagrammatically:

[0173] FIG. 1 shows a first embodiment of a carrier substrate according to the invention,

[0174] FIG. 2 shows a second embodiment of a carrier substrate,

[0175] FIG. 3 shows a first embodiment of a product substrate,

[0176] FIG. 4 shows a second embodiment of a product substrate,

[0177] FIG. 5 shows a third embodiment of a product substrate,

[0178] FIG. 6a shows a first process step of a first method according to the invention,

[0179] FIG. 6b shows a second process step of a first method according to the invention

[0180] FIG. 6c shows a third process step of a first method according to the invention and

[0181] FIG. 6d shows a fourth process step of a first method according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0182] Identical components or components with the same function are denoted by the same reference numbers in the figures.

[0183] In the figures, the representation of unnecessary components, in particular of substrate holders, is completely dispensed with, since they are not necessary for describing the process. The figures and the individual parts of the representations are not true to scale. The figures are made more comprehensible by the representation not being true to scale. In particular, transfer layer 6, which is described below by way of example in the form of a graphene layer 6, is shown very thick, although it is only a monoatomic layer. In addition, protective layer 5 or growth layer 5 is shown as one layer in the figures. This is the preferred embodiment, in which protective layer 5, apart from the protection, is also designed as a growth layer 5. At all events, a protective layer 5 is provided. It is however also conceivable to arrange an additional growth layer on protective layer 5 in order to generate transfer layer 6. However, a layer with the protection function is preferred which is also suitable for generating or growing a transfer layer 6.

[0184] FIG. 1 shows a carrier substrate 1 with a produced layer system in a first embodiment. The layer system comprises a release layer 4, which is applied on carrier base substrate 3. Located on release layer 4 is a growth layer 5 or a protective layer 5. Growth layer 5 has itself preferably been transferred by a layer transfer process onto release layer 4 or has been deposited directly on release layer 4 by a physical or chemical deposition process. A transfer layer 6 or graphene layer 6 has been generated on growth layer 5. The thicknesses of carrier base substrate 3, release layer 4, growth layer 5 and in particular graphene layer 6 are not represented true to scale. In particular, graphene layer 6 as a monoatomic layer should have been represented very much thinner, in particular only as a single line. In order to improve the representation, a representation true to scale has however been dispensed with.

[0185] FIG. 2 shows a carrier substrate 1′ with a produced layer system in a second embodiment. Carrier substrate 1′ has a deposited or transferred contact layer 8 on transfer layer 6 or graphene layer 6.

[0186] FIG. 3 shows a product substrate 2 in a first embodiment. Product substrate 2 in particular comprises only product base substrate 7.

[0187] FIG. 4 shows a product substrate 2′ in a second embodiment. Product substrate 2′ comprises only product base substrate 7 and a contact layer 8 deposited or transferred thereon. Contact layer 8 is preferably a dielectric layer, most preferably a silicon oxide layer.

[0188] FIG. 5 shows a product substrate 2″ in a third embodiment. Product substrate 2″ comprises a product base substrate 7′. In particular, functional components 9 have already been produced in product base substrate 7′. Contact layer 8′ has preferably been deposited above product base substrate 7′. Contact layer 8′ preferably comprises electrically conductive through-contact vias 10, which are intended to connect the, in particular functional, components 9 to the transfer layer to be transferred or the graphene layer (not shown). This embodiment would also be conceivable without contact layer 8′. In this case, through-contact vias 10 would also be absent and a transferred transfer layer or graphene layer (not shown) would directly contact contact points of the, in particular functional, component 9 (not shown). Contact layer 8′ is once again preferably a dielectric layer, most preferably a silicon oxide layer.

[0189] The following FIGS. 6a to 6d show a first method or a process for transferring a transfer layer by way of example with the aid of a carrier substrate 2′ and a product substrate 2′. The process can however be carried out by any carrier substrate-product substrate combination, in particular also by carrier substrates and/or product substrates which are not explicitly, represented, inasmuch as the layer system, comprising release layer 4, growth layer 5 and transfer layer 6 to be transferred or graphene layer 6, are present in this sequence.

[0190] Furthermore, in the following figures product substrate 2′ is represented at the upper side and carrier substrate 1′ at the underside. It is also conceivable for carrier substrate to be located at the upper side and product substrate 1′ at the underside. For the sake of clarity, the representation of substrate holders, bonding devices and alignment devices is dispensed with.

[0191] FIG. 6a shows a first process step of a first method or a first process for transferring a transfer layer, wherein a product substrate 2′, comprising a product base substrate 7 and a contact layer 8′, is aligned relative to a carrier substrate 1. Contact layer 8 is preferably an oxide, most preferably a silicon oxide. Carrier substrate 1 comprises a carrier base substrate 3, a release layer 4, a growth layer 5, as well as transfer layer 6 or graphene layer 6 to be transferred. How graphene layer 6 has been generated or has been transferred on growth layer 5 is not relevant for an understanding of the process and will not therefore be described in greater detail. The alignment can take place mechanically and/or optically. In the case of an optical alignment, alignment marks (not shown) in particular are present on product substrate 2′ and on carrier substrate 1.

[0192] FIG. 6b shows a second process step of the first process, wherein contacting between carrier substrate 1 and product substrate 2′ takes place. It is not represented in the figure how the contacting precisely takes place, since it is not relevant for the process. The contacting preferably takes place, however, by means of a device in which at least one of the two substrates 1, 2′ is curved. The contacting process is therefore preferably carried out with the aid of a fusion bonding system. In a very particularly preferred embodiment of the process, the, in particular upper, product substrate 2′ is curved, whereas the, in particular lower, carrier substrate 1 is fixed over the entire area.

[0193] FIG. 6c shows a third process step of the first process. Release layer 4 is acted upon by a debonding means 11. Debonding means is preferably a laser. The debonding means preferably acts via carrier base substrate 3 on release layer 4. Growth layer 5 acts as a protective shield for graphene layer 6 lying behind. Since graphene layer 6 is a rnonoatomic layer, graphene layer 6 could be destroyed by debonding means 11 with high intensities. Growth layer 5, which is preferably also used to generate graphene layer 6, is therefore used as a protective shield. Growth layer 5 thus has to be designed in such a way that bonding means 11 used in each case is blocked in the best possible way during the debonding process or influences on transfer layer 6 arising from debonding means 11 are at least very markedly reduced. If debonding means 11 is a laser, growth layer 5 should have a transmissivity as low as possible for the photons of laser 11. If debonding means 11 involves for example heat which is introduced by a heat source, growth layer 5 should have a thermal conductivity as low as possible, in order to make the transport of heat to graphene layer 6 difficult.

[0194] It is clear to the expert in the field that an arbitrary number of other layers can be present between release layer 4 and growth layer 5, which can perform the particular function of protection of transfer layer 6. Thus, it would be conceivable to insert a further layer between release layer 4 and growth layer 5, which further layer absorbs the laser radiation or heat of a debonding means 11 extremely well. For the sake of simplicity, however, this property is combined in a single growth layer 5, in order not to complicate either the description or the representation. In particular, it is advantageous if growth layer 5, which is preferably used for the growth of graphene layer 6, at the same time also serves as its protective layer for used debonding means 11. A very cost-effective process can thus be carried out, because it is not necessary to deposit further expensive layers. A further advantage includes the fact that growth layer 5 is particularly preferably a metal layer, most preferably a nickel layer. As is known, metals are very good infrared absorbers. The most preferred debonding means 11 is a laser, preferably an infrared laser. Metallic growth layer 11, in this special case on account of its solid state properties, can thus serve simultaneously as growth layer 5 and as a protective layer. If debonding means 11 were a heat source, a metallic rowth layer 5 would of course be less than optimal on account of the relatively high thermal conductivity. In this case, further layers are preferably inserted between growth layer 5 and release layer 4, in particular ones with low thermal conductivity.

[0195] FIG. 6d shows a first variant of a fourth process step of the first process, wherein also transferred growth layer 5 (no longer shown) has already been removed. A transfer layer 6 or a graphene layer 6 is obtained on a product substrate 2e, which represents the end product of the process. Product substrate 2e, in particular transferred graphene layer 6, can then be further processed in further process steps. The two other variants for the use of growth layer 5, which have already been mentioned, are no longer represented graphically here, since no further conclusions concerning the actual process can be drawn from them.

LIST OF REFERENCE NUMBERS

[0196] 1 carrier substrate

[0197] 2, 2′, 2″, 2e product substrate

[0198] 3 carrier base substrate

[0199] 4 release layer

[0200] 5 growth layer, protective layer

[0201] 6 transfer layer, gra.phene layer

[0202] 7, 7′ product base substrate

[0203] 8, 8′ contact layer

[0204] 9 functional units

[0205] 10 through-contact vias

[0206] 11 debonding means