COMBINED WAFER PRODUCTION METHOD WITH A RECEIVING LAYER HAVING HOLES

Abstract

The present invention relates to a method for producing solid body layers. The claimed method comprises at least the following steps: providing a solid body (2) for separating at least one solid body layer (4), fixing the receiving layer (10) for holding the solid layer (4) to the solid body (2), said receiving layer having a plurality of holes for guiding a fluid and is fixed by means of a connecting layer to the solid body and the receiving layer (10) is subjected to thermal stress, in particular, mechanical stress, for generating voltages in the solid body (2), wherein a crack in the solid body (2) along a separation plane (8) expands due to the voltages, the solid layer (4) being separated from the solid body (2) due to the crack.

Claims

1. A method for producing solid layers, at least comprising the steps: providing a solid (2) for separating at least one solid layer (4), fixing an accommodating layer (10) for holding the solid layer (4) on the solid (2), wherein the accommodating layer has a multiplicity of holes (36), particularly for conducting a liquid, wherein the accommodating layer is fixed on the solid (2) by means of a connecting layer (11), and thermal loading of the accommodating layer (10) for the, in particular mechanical, generation of stresses in the solid (2), wherein a crack in the solid (2) propagates along a detachment plane (8) due to the stresses, wherein the solid layer (4) is separated from the solid (2) by means of the crack.

2. The method according to claim 1, characterized in that the holes (36) have a diameter of less than 1 mm, preferably of less than 0.5 mm and particularly preferably of less than 0.1 mm.

3. The method according to claim 1 or claim 2, characterized in that the accommodating layer has more than 10 holes (36), preferably more than 100 holes (36) and particularly preferably more than 1000 holes (36).

4. The method according to one of the preceding claims, characterized in that at least one further hole is formed in a radius of less than 50 mm, preferably less than 25 mm and particularly preferably less than 5 mm around the centre of each hole.

5. The method according to one of the preceding claims, characterized in that for detaching the accommodating layer from the solid, a fluid, particularly a liquid, can therefore be supplied to the connecting layer through the holes, wherein the fluid causes the fixing of the accommodating layer on the solid to be weakened or terminated.

6. The method according to one of the preceding claims, characterized in that defects are created in the inner structure of the solid to predefine the detachment plane by means of at least one radiation source (18), particularly a laser, particularly an fs laser, before or after the application of the accommodating layer on the solid.

7. The method according to claim 6, characterized in that the radiation source (18) is set up in such a manner that the beams (6) emitted by it for creating the detachment plane (8) penetrate into the solid (2) to a defined depth of less than 200 μm, preferably of less than 100 μm and further preferably of less than 50 μm and particularly preferably of less than 20 μm.

8. The method according to claim 6, characterized in that the radiation source is set up in such a manner that the beams (6) emitted by it for creating the detachment plane (8) penetrate into the solid (2) to a defined depth of more than 100 μm, preferably of more than 200 μm and further preferably of more than 400 μm and particularly preferably of more than 700 μm.

9. The method according to one of the preceding claims 6 to 8, characterized in that the radiation source, particularly the laser, has a pulse duration of less than 10 ps, preferably of less than 1 ps and particularly preferably of less than 500 fs.

10. The method according to one of the preceding claims 6 to 9, characterized in that the energy of the laser beam, particularly of the fs laser, is chosen in such a manner that the damage propagation in the solid is smaller than 3-times the Rayleigh length, preferably smaller than the Rayleigh length and particularly preferably smaller than a third of the Rayleigh length.

11. The method according to one of the preceding claims 6 to 10, characterized in that the wavelength of the laser beam, particularly of an fs laser, is chosen such that the absorption of the solid is lower than 10 cm.sup.−1 and preferably lower than 1 cm.sup.−1 and particularly preferably smaller than 0.1 cm.sup.−1.

12. The method according to one of the preceding claims 6 to 11, characterized in that the individual defects are in each case created as a consequence of multiple-photon excitation effected by the laser, particularly fs laser.

13. A wafer, produced according to a method according to one of claims 1 to 12.

14. A film for generating stress in a solid, wherein the film comprises at least one polymer material, particularly PDMS, wherein the polymer material undergoes a glass transition at a temperature lower than 0° C., particularly at a temperature lower than −50° C., characterized in that the film has a multiplicity of holes for conducting a liquid, wherein the holes in each case have a diameter of less than 5 mm.

15. The use of a film according to claim 14 as an accommodating layer in a method according to claim 1.

Description

[0052] In the figures:

[0053] FIG. 1a shows a schematic design for generating local stresses in a solid;

[0054] FIG. 1b shows a schematic illustration of a layer arrangement before the separation of a solid layer from a solid;

[0055] FIG. 1c shows a schematic illustration of a layer arrangement after the separation of a solid layer from a solid;

[0056] FIG. 2a shows a first schematically illustrated variant for generating local stresses by means of radiation, particularly light waves;

[0057] FIG. 2b shows a second schematically illustrated variant for generating local stresses by means of radiation, particularly by means of light waves;

[0058] FIG. 3a shows an accommodating layer according to the invention;

[0059] FIG. 3b shows an accommodating layer according to the invention, which is arranged on a solid;

[0060] FIG. 3c shows a second accommodating layer according to the invention, which is arranged on a solid;

[0061] FIG. 3d shows a third accommodating layer according to the invention, which is arranged on a solid; and

[0062] FIG. 3e shows a fourth accommodating layer according to the invention, which is arranged on a solid.

[0063] A workpiece 2 or a substrate is shown in FIG. 1a, which is arranged in the region of a radiation source 18, particularly a laser, particularly a femtosecond laser (fs laser). The workpiece 2 preferably has a first, particularly planar, area segment 14 and a second, particularly planar, area segment 16, wherein the first planar area segment 14 is preferably orientated substantially or exactly parallel to the second planar area segment 16. The first planar area segment 14 and the second planar area segment 16 preferably delimit the workpiece 2 in a Y direction, which is preferably orientated vertically. The planar area segments 14 and 16 preferably extend in each case in an X-Z plane, wherein the X-Z plane is preferably orientated horizontally. Furthermore, it can be drawn from this illustration that the radiation source 18 radiates beams 6 simultaneously or in a time-offset manner onto the workpiece 2. Depending on the configuration, the beams 6 penetrate to a defined depth into the workpiece 2 and generate local stresses at the respective position or at a predetermined position.

[0064] In FIG. 1b, a multiple-layer arrangement is shown, wherein the workpiece 2 contains the crack guidance layer 8 and is provided with a holding layer 12 in the region of the first planar area segment 14, which in turn is preferably overlaid by a further layer 20, wherein the further layer 20 is preferably a stabilizing device, particularly a metal plate. A polymer layer 10 is preferably arranged on the second planar area segment 16 of the workpiece 2. The accommodating layer or polymer layer 10 and/or the holding layer 12 preferably consist at least to some extent and particularly preferably completely from PDMS and particularly preferably has a multiplicity of holes, particularly blind holes and/or through holes.

[0065] A state after crack formation and subsequent crack guidance is shown in FIG. 1c. The solid layer 4 adheres on the polymer layer 10 and is spaced or can be spaced from the remainder of the workpiece 2.

[0066] Examples for the creation, shown in FIG. 1a, of a crack guidance layer 8 by introducing local stresses into a workpiece 2, particularly by means of light beams, are shown in FIGS. 2a and 2b.

[0067] The present invention therefore relates to a method for producing solid layers. The method according to the invention can in this case additionally or alternatively comprise one, a plurality or all of the steps listed below, particularly providing a workpiece 2 for separating at least one solid layer 4, generating preferably defined local stresses or local stresses by means of at least one radiation source, particularly an fs laser, in the inner structure of the solid for predefining a crack guidance layer, along which the solid layer is separated from the solid, and thermal loading of a polymer layer 10 arranged on the workpiece 2, for, in particular mechanical, generation of detachment stresses in the workpiece 2, wherein a crack in the workpiece 2 propagates along the crack guidance layer 8 due to the detachment stresses, which crack separates the solid layer 4 from the workpiece 2. The local stresses here preferably cause the crack propagation to take place in the desired crack guidance layer 8.

[0068] In FIG. 2a, it is therefore shown schematically how local stresses 34 can be generated in a workpiece 2, particularly for creating a crack guidance layer 8 by means of a radiation source 18, particularly one or more lasers, particularly a plurality of fs lasers. The radiation source 18 in this case emits radiation 6 with a first wavelength 30 and a second wavelength 32. The wavelengths 30, 32 are in this case preferably adapted to one another in such a manner or the distance between the radiation source 18 and the crack guidance layer 8 to be created is preferably adapted in such a manner that the waves 30, 32 coincide substantially or exactly on the crack guidance layer 8 in the workpiece 2, as a result of which local stresses or defects are created at the site of the coincidence 34 as a consequence of the energies of the two waves 30, 32. The generation of the local stresses can in this case take place by means of different or combined mechanisms, such as e.g. sublimation, fusing and/or chemical reaction.

[0069] A focussed laser beam 6 is shown in FIG. 2b, the focal point of which preferably lies in the crack guidance layer 8. It is conceivable here that the light beam 6 is focussed by one or more focussing bodies, particularly (a) lens(es) (not shown). The workpiece 2 is constructed with multiple layers in this embodiment and preferably has a partially transparent or transparent substrate layer 3 or material layer, which preferably consists of sapphire or comprises sapphire. The light beams 6 reach through the substrate layer 3 to the crack guidance layer 8, which is preferably formed by a sacrificial layer 5, wherein the sacrificial layer 5 is loaded by the radiation in such a manner that the generation of local stresses in the sacrificial layer 5 is effected at the focal point or in the region of the focal point. It is likewise conceivable that the local stresses for creating the crack guidance layer 8 are generated in the region of or precisely on a boundary surface between two layers 3, 4. Thus, it is likewise conceivable that the solid layer 4 is created on a support layer, particularly a substrate layer 3, and a crack guidance layer 8 for detaching or separating the solid layer 4 can be created by means of one or more sacrificial layers 5 and/or by means of the generation of local stresses in a boundary surface, particularly between the solid layer 4 and the support layer.

[0070] FIG. 3a shows an accommodating layer 10 or film according to the invention for generating stress in a solid. In this case, the film preferably has at least one polymer material, particularly PDMS, wherein the polymer material undergoes a glass transition at a temperature lower than 20° C., particularly at lower than 10° C., particularly at lower than 0° C., particularly at a temperature lower than −50° C. The film particularly preferably has a multiplicity of holes 36 for conducting a liquid, wherein the holes 36 in each case have a diameter of less than 5 mm.

[0071] FIG. 3b shows a solid 2 and a solid layer 4 separated therefrom. An accommodating layer 10 or a film 10 is also arranged on the solid layer 4, by means of which accommodating layer or film the stresses required for creating a crack for separating the solid layer 4 from the solid 2 were generated. The accommodating layer 10 has a multiplicity of holes for conducting a liquid, wherein the accommodating layer 10 is fixed on the solid layer 4 by means of a connecting layer 11.

[0072] FIG. 3c shows a further accommodating layer 10 or film according to the invention, which can preferably likewise be arranged or is arranged on the solid 4 by means of a connecting layer 11. The accommodating layer 10 in this case preferably has a first material portion 39, particularly a polymer portion, and a second material portion 40, particularly a metal portion. The second material portion 40 in this case preferably constitutes a coating of the first material portion 39 and particularly preferably is used for accelerated cooling of the first material portion 39. The accommodating layer 10 is in this case preferably loaded from direction 38 with cold, particularly liquid nitrogen, as a result of which the second material portion 40 rapidly cools down and in particular by means of the direct contact with the first material portion 39, likewise cools the same very fast.

[0073] FIG. 3d shows a further variant of the accommodating layer 10 or film according to the invention, which is in turn formed by the first material portion 39 and the second material portion 40. The first material portion 39 preferably has holes 36, which are filled by the second material portion 40. Preferably, the second material portion 40 likewise coats the first material portion 39 on the upper side, i.e. parallel to the connecting layer 11.

[0074] FIG. 3e shows another further variant of the accommodating layer 10 or film according to the invention, which is in turn formed by the first material portion 39 and the second material portion 40. The first material portion 39 preferably has holes 36, which are lined by the second material portion 40, i.e. the wall delimiting the respective hole 36 is coated with the second material portion. Preferably, the second material portion 40 likewise coats the first material portion 39 on the upper side, i.e. parallel to the connecting layer 11.

[0075] Furthermore, it is preferably additionally or alternatively conceivable that the method for producing solid layers comprises one, a plurality or all of the following mentioned steps: Providing a solid 2 for separating at least one solid layer 4, arranging an accommodating layer 10 for holding the solid layer 4 on the solid 2, wherein the accommodating layer consists at least of a polymer and a further material, wherein the accommodating layer preferably mostly consists of the polymer in terms of volume and/or in terms of mass, wherein the further material has a greater conductivity than the polymer, thermal loading of the accommodating layer 10 for the, in particular mechanical, generation of stresses in the solid 2, wherein a crack in the solid 2 propagates along a detachment plane 8 due to the stresses, wherein the solid layer 4 is separated from the solid 2 by means of the crack.

[0076] Furthermore, the film according to the invention for generating stress in a solid preferably comprises at least one polymer material, particularly PDMS, and a further material, wherein the film mostly consists of the polymer material in terms of volume, wherein the material has a greater thermal conductivity than the polymer material, wherein the polymer material preferably undergoes a glass transition at a temperature lower than 0° C., particularly at a temperature lower than −50° C.

REFERENCE LIST

[0077] 2 Workpiece [0078] 3 Substrate [0079] 4 Solid layer [0080] 5 Sacrificial layer [0081] 6 Radiation [0082] 8 Crack guidance layer [0083] 10 Accommodating layer/film [0084] 11 Connecting layer [0085] 12 Holding layer [0086] 14 First planar area segment [0087] 16 Second planar area segment [0088] 18 Radiation source/defect-creating device [0089] 20 Stabilizing device [0090] 36 Hole [0091] 38 Loading with cold [0092] 39 First material portion [0093] 40 Second material portion [0094] X First direction [0095] Y Second direction [0096] 2 Third direction