METHOD FOR JOINING AT LEAST TWO COMPONENTS

Abstract

The invention relates to a method for connecting at least two components (1, 2), comprising the following steps: A) providing at least a first component (1) and a second component (2), B) applying at least one donor layer (3) to the first and/or the second component (1, 2), wherein the donor layer (3) is enriched with oxygen (31), C) applying a metal layer (4) to the donor layer (3), the first or the second component (1, 2), D) heating at least the metal layer (4) to a first temperature (T1) such that the metal layer (4) is melted and the first component (1) and the second component (2) are connected to one another, and E) heating the arrangement to a second temperature (T2) such that the oxygen (31) passes from the donor layer (3) into the metal layer (4) and the metal layer (4) is converted to form a stable metal oxide layer (5), wherein the metal oxide layer (5) has a higher melting temperature than the metal layer (4), wherein at least the donor layer (3) and the metal oxide layer (5) connect the first component (1) and the second component (2) to one another.

Claims

1. Method for connecting at least two components, comprising the following steps: A) providing at least a first component and a second component, B) applying at least one donor layer to the first and/or the second component, wherein the donor layer comprises an oxide of at least one metal and is enriched with oxygen, so that the donor layer has a superstoichiometric proportion of oxygen, C) applying a metal layer to the donor layer, the first or the second component, D) heating at least the metal layer to a first temperature (T1) such that the metal layer is melted and the first component and the second component are connected to one another, and E) heating the arrangement to a second temperature (T2) such that the oxygen passes from the donor layer into the metal layer and the metal layer is converted to form a stable metal oxide layer, wherein the metal oxide layer has a higher melting temperature than the metal layer, wherein at least the donor layer and the metal oxide layer connect the first component and the second component to one another.

2. Method according to claim 1, wherein the donor layer is composed of indium tin oxide, indium oxide, zinc oxide or tin oxide, wherein the indium tin oxide, indium oxide or tin oxide is enriched with oxygen.

3. Method according to claim 1, wherein the metal layer comprises indium, tin, zinc or a combination of indium and tin, wherein indium oxide is formed as the metal oxide layer in the case of indium as the metal layer, wherein tin oxide is formed as the metal oxide layer in the case of tin as the metal layer, wherein zinc oxide is formed as the metal oxide layer in the case of zinc as the metal layer, and wherein indium tin oxide is formed as the metal oxide layer in the case of a mixture of indium and tin as the metal layer.

4. (canceled)

5. Method according to claim 1, wherein the donor layer and the metal oxide layer comprise the same metal oxides after step D).

6. Method according to claim 1, wherein the donor layer and the metal layer are produced by sputtering and the metal oxide layer is produced by oxidation of the metal layer.

7. Method according to claim 6, wherein the donor layer is produced by means of sputtering, in step B), of at least one metal and of oxygen to form a metal oxide, wherein the metal layer is produced by sputtering, in the same system, of at least one metal, wherein the metal of the metal layer corresponds to the metal of the metal oxide of the donor layer.

8. Method according to claim 7, wherein, in step B), a continuous oxygen stream is introduced into the donor layer at a speed rate k1 and with a proportion n1 to introduce the oxygen, wherein the oxygen stream in step C) has a speed rate k2<k1 and a proportion n2<n1 such that the metal layer is produced.

9. Method according to claim 1, wherein the second component comprises a light-emitting diode, and wherein at least the first component is selected from a group consisting of sapphire, silicon nitride, a semiconductor material, a ceramic material, a metal and glass.

10. Method according to claim 1, wherein the first component and/or the second component is a pipe and/or tube.

11. Method according to claim 1, wherein the second temperature (T2) in step E) is greater than the first temperature (T1) in step D) and the first and the second temperature (T1, T2) differ from one another by at least the factor 1.5.

12. Method according to claim 1, wherein the oxygen of the donor layer is introduced into the donor layer after step B) by means of an ion implantation method, or wherein the oxygen of the donor layer is introduced into the donor layer during step B) by means of an oxygen stream.

13. Method according to claim 1, wherein the first and the second component are connected under a pressure of at least 1.8 bar.

14. Structural element comprising at least two semiconductor layer sequences (H1, H2) which are each designed to emit radiation in the same or a different wavelength range, wherein two donor layers and a metal oxide layer are arranged between the at least two semiconductor layer sequences (H1, H2), wherein one donor layer is arranged directly on one semiconductor layer sequence (H1) and the other donor layer is arranged directly on the other semiconductor layer sequence (H2), and wherein the metal oxide layer is arranged directly between the two donor layers.

15. Structural element according to claim 14, wherein the two donor layers and the metal oxide layer are each formed from an identical transparent conductive material.

Description

[0047] Further advantages, advantageous embodiments and developments will become apparent from the exemplary embodiments described hereinbelow in conjunction with the figures.

[0048] In the figures:

[0049] FIGS. 1A to 5C each show a schematic side view of a method for connecting at least two components according to one embodiment.

[0050] In the exemplary embodiments and figures, identical elements, similar elements or elements having the same effect may each be provided with the same reference numerals. The elements shown and the size ratios thereof in relation to one another are not to be considered as true to scale. Instead, individual elements such as, for example, layers, components, structural elements and regions may be shown with an exaggerated size for better illustration and/or for better understanding.

[0051] FIGS. 1A and 1B show a method for connecting or joining at least two components according to one embodiment. FIG. 1A shows the provision at least of the first component 1 and of the second component 2 (step A)). The donor layer 3 is applied to the first component 1 and/or second component 2 in particular in direct mechanical and/or electrical contact. The donor layer 3 is enriched in particular with oxygen 31. By way of example, the donor layer is formed from indium tin oxide. The oxygen 31 in the indium tin oxide accumulates in particular in the interstices of the crystal lattice of the mixed oxide indium tin oxide (ITO). In particular, a metal layer 4 is arranged directly subsequent to the donor layer 3. The donor layer 3 and the metal layer 4 are applied in particular by sputtering from the same system. In particular, the metal layer comprises a metal which is the same as the metal of the metal oxide or mixed metal oxide of the donor layer 3 (steps B) and C)). This is followed by the heating at least of the metal layer 4 or of the entire arrangement comprising the first and/or second component, the donor layer 3 and the metal layer 4 to a first temperature T1. In particular, the first temperature T1 is so high that the metal layer 4 is melted and connects the first component 1 and the second component 2 to one another. In particular, this is a mechanical and/or electrical connection (step D)). Then, the arrangement can be heated to a second temperature T2, such that the oxygen 31 passes from the donor layer 3 into the metal layer 4. A metal oxide layer 5 is formed from the metal layer 4, which comprises a metal, by oxidation. The metal oxide layer 5 is in particular mechanically stable and/or transparent. In this case, the metal oxide layer 5 has a higher remelting temperature than the metal layer 4. This produces an outstanding connection between the first and the second component 1, 2.

[0052] FIG. 1B shows a schematic side view when the two components are connected to one another. In this case, the arrangement comprises a first component 1, followed by a donor layer 3, followed by a metal oxide layer 5, followed by a second component 2. As an alternative, the donor layer 3 may also be arranged subsequent to the second component 2. The metal oxide layer 5 is then arranged subsequent to the donor layer 3 and in turn the first component 1 is arranged subsequent to said metal oxide layer.

[0053] FIGS. 2A and 2B show the connection of at least two components 1, 2 according to one embodiment. The donor layer 3 can be applied to the first component 1. The donor layer 3 is enriched in particular with oxygen 31 (not shown here). The metal layer 4 can be applied to the second component 2. Then, method steps D) and E) can be carried out. This forms a structural element 100 comprising a first component 1, followed by a donor layer 3, followed by a metal oxide layer 5, followed by a second component 2. In other words, the metal layer 4 is converted into the metal oxide layer 5 by oxidation with the oxygen 31 present in the donor layer.

[0054] FIGS. 3A to 3B show a method for connecting at least two components 1, 2. FIG. 3A shows a component 1. Alternatively, FIG. 3A shows a second component 2. The components 1, 2 have in particular a tubular shape. In particular, the two components 1, 2 are each a pipe. A donor layer 3 is applied to the cross-sectional areas of the respective component 1, 2. Then, a metal layer 4 can be applied (FIG. 3B). At least two pipes are connected or joined in order to produce a fixed connection between the two pipes (FIG. 3C).

[0055] FIGS. 4A and 4B show a method for connecting at least two components 1, 2 according to one embodiment. In particular, the second component 2 comprises an optoelectronic semiconductor component or an LED. FIGS. 4A and 4B differ from FIGS. 1A and 2B in that two second components 2 are applied to a first component 1. As an alternative or in addition, it is also possible for more than two second components 2 to be applied to a first component 1, or vice versa. A donor layer 3 enriched with oxygen 31 can be applied to a first component 1. This is followed by the application of a metal layer 4 and the application of the second components 2. The first and second components 1, 2 are connected to one another in step D), the metal layer 4 being heated in said step to a first temperature T1 such that the melting temperature is exceeded. As a result, the metal layer 4 is present in molten form and can produce a connection between the first component and each second component 2. In a further heating step at a second temperature T2, the metal layer can be converted into a metal oxide layer 5 with the oxygen 31 of the donor layer 3. What results is a connecting element comprising a donor layer 3 and a metal oxide layer 5, which produces a fixed mechanical and/or electrical connection between the two components 1, 2. Then, the second components 2, which are located on a common first component 1, can be singulated 7. This can be effected, for example, by means of sawing or a laser separation method.

[0056] It is also possible in particular for III-V semiconductor layers to be arranged on a first and/or second component 1, 2. In particular, the first and/or second component 1, 2 is then formed as a growth substrate. Firstly, a donor layer 3 composed of a metal oxide, for example indium tin oxide, can be applied to the exposed surface of the III-V semiconductor layers.

[0057] The donor layer 3 composed of indium tin oxide comprises in particular a superstoichiometric proportion of oxygen. In particular, the donor layer 3 is deposited with a thickness of 60 nm. The donor layer 3 is reactive; i.e., for example, the metal particles, for example indium and tin, react with the oxygen to form a metal oxide, such as indium tin oxide.

[0058] The donor layer 3 is applied by sputtering, with oxygen being added to the process gas. In particular, the composition of the target used for sputtering is 90% by weight indium and 10% by weight tin. In a further process, the admixture of oxygen to the process gas is interrupted such that, at least with an increasing thickness of the applied donor layer 3, in particular of the indium tin layer, a decreasing quantity of oxygen is present therein. In particular, sputtering is continued until a metal layer 4, in particular composed of indium and tin, is present on the surface.

[0059] The metal layer 4 has in particular a thickness of 4 to 8 nm, for example 5 nm. Then, the first and the second component 1, 2 can be connected to one another, in particular connected. The connection can be carried out in particular at a first temperature T1 of <200 C., for example at 180 C. Proceeding from room temperature, i.e. proceeding from 25 C., the components 1, 2 are heated to the first temperature T1 used for the connection. When the first temperature T1 has been reached, the layers are pressed onto one another in particular with a pressure of >1.8 bar, for example 2 bar. The components 1, 2 can be held in this state for approximately five minutes.

[0060] Then, the temperature can be increased further to a second temperature T2, for example to up to 350 C. The two components 1, 2 can be fired at this temperature for one hour. In this process, it is the case in particular that the oxygen 31 diffuses from the donor layer 3 into the metal layer 4, which consists in particular of indium tin, and converts the metal of the metal layer 4 into a metal oxide layer 5.

[0061] In particular, the metal oxide layer 5 is ceramic. As an alternative or in addition, the metal oxide layer 5 is optically transparent. As an alternative or in addition, the metal oxide layer 5 is electrically conductive. The metal oxide layer preferably consists of indium tin oxide. The connection between the first and the second component 1, 2 via the donor layer 3 and the metal oxide layer 5 thus has a drastically higher melting point than the metal layer 4 beforehand. In addition, the metal oxide layer 5 can have a transparent form as compared to the metal layer 4.

[0062] FIGS. 5A to 5C show a method for connecting or joining at least two semiconductor layer sequences H1, H2 according to one embodiment. FIG. 1A shows the provision at least of the first component 1, which comprises a semiconductor layer sequence H1 and a growth substrate W1, for example composed of sapphire. FIG. 1A furthermore shows the provision at least of the second component 2, which comprises a semiconductor layer sequence H2 and a growth substrate W2, for example composed of sapphire. The donor layer 3 is applied both to the first component 1 and to the second component 2 in particular in direct mechanical and/or electrical contact, and then the metal layer 4 is applied in each case.

[0063] This is followed by the connection of the two components 1, 2, the metal layer 4 being converted into a metal oxide layer 5 (FIG. 5B). This results in the following layer structure: growth substrate W2semiconductor layer sequence H2donor layer 3metal oxide layer 5donor layer 3semiconductor layer sequence H1growth substrate W1.

[0064] The semiconductor layer sequences H1, H2 in particular directly adjoin the respective donor layers 3.

[0065] Then, as shown in FIG. 5C, the growth substrate W1 of the first component 1 can be removed, and a donor layer 3 and a metal layer 4 can be applied to the semiconductor layer sequence H1. The steps of FIG. 5A can then be repeated as desired with further components, for example the first, second or a third component 3, this resulting in a structural element which comprises, for example, three semiconductor layer sequences H1, H2, H3, with adjacent semiconductor layer sequences being separated from one another in each case by at least one donor layer 3, in particular two donor layers 3, and a metal oxide layer 5. In particular, the semiconductor layer sequences H1, H2, H3 emit radiation of a differing wavelength, for example radiation from the red, yellow and blue wavelength range, such that the total emission of the structural element 100 can have any wavelength in the visible range, for example white mixed light. In particular, the respective donor layers 3 and the metal oxide layers 5 are formed from indium tin oxide. Absorption losses of the emitted radiation can thereby be reduced.

[0066] The exemplary embodiments described in conjunction with the figures and the features thereof can also be combined with one another in accordance with further exemplary embodiments, even if such combinations are not shown explicitly in the figures. Furthermore, the exemplary embodiments described in conjunction with the figures can have additional or alternative features in accordance with the description in the general part.

[0067] The invention is not restricted to the exemplary embodiments by the description on the basis of said exemplary embodiments. Rather, the invention encompasses any novel feature and also any combination of features, which in particular includes any combination of features in the patent claims, even if this feature or this combination itself is not explicitly specified in the patent claims or exemplary embodiments.

[0068] This patent application claims the priority of German patent application 10 2015 111 040.7, the content of the disclosure of which is hereby incorporated by reference.