Component Composite and Method for Probing and Producing Components
20220393059 · 2022-12-08
Inventors
- Korbinian Perzlmaier (Regensburg, DE)
- Peter Stauß (Regensburg, DE)
- Alexander F. Pfeuffer (Regensburg, DE)
- Christoph Klemp (Regensburg, DE)
- Kerstin Neveling (Pentling, DE)
- Andreas Biebersdorf (Regensburg, DE)
Cpc classification
H01L33/0095
ELECTRICITY
H01L33/30
ELECTRICITY
H01L2221/68381
ELECTRICITY
International classification
H01L33/00
ELECTRICITY
Abstract
In an embodiment a component composite includes an auxiliary carrier, a plurality of components, a retaining structure and an electrically conductive sacrificial layer, wherein each of the components has a connection layer which faces the sacrificial layer and is electrically conductively connected to the sacrificial layer, wherein the sacrificial layer is arranged in vertical direction between the auxiliary carrier and the components, and wherein the sacrificial layer is to be removable and the components are mechanically connected to the auxiliary carrier only via the retaining structure in addition to the sacrificial layer.
Claims
1.-18. (canceled)
19. A component composite comprising: an auxiliary carrier; a plurality of components; a retaining structure; and an electrically conductive sacrificial layer, wherein each of the components has a connection layer which faces the sacrificial layer and is electrically conductively connected to the sacrificial layer, wherein the sacrificial layer is arranged in vertical direction between the auxiliary carrier and the components, and wherein the sacrificial layer is to be removable and the components are mechanically connected to the auxiliary carrier only via the retaining structure in addition to the sacrificial layer.
20. The component composite according to claim 19, wherein the components are laterally spaced from one another by separation trenches and the sacrificial layer is freely accessible in regions in the separation trenches.
21. The component composite according to claim 19, wherein for each component the retaining structure has a vertically projecting retaining element which—in plan view of the auxiliary carrier—is completely covered by the associated component.
22. The component composite according to claim 19, wherein for each component, the retaining structure has a vertically projecting retaining element which, in plan view of the auxiliary carrier, is arranged in regions below and in regions to a side of the associated component.
23. The component composite according to claim 19, wherein the components are to be transferable in that, after removal of the sacrificial layer, the components are mechanically connected to the auxiliary carrier exclusively via the retaining structure and are detachable from the retaining structure and thus from the auxiliary carrier.
24. The component composite according to claim 19, wherein the retaining structure is an anchoring layer formed of a metal, an electrically conductive oxide, an electrically insulating material, an epoxy, a thermoset, or a benzocyclobutene-based material.
25. The component composite according to claim 24, wherein the retaining structure has an atomic layer deposition layer as a passivation layer which is arranged on the anchoring layer.
26. The component composite according to claim 19, wherein each of the components comprises a front-side contact layer and a rear-side contact layer, wherein the front-side contact layer and the rear-side contact layer are assigned to different electrical polarities of the associated component, wherein the rear-side contact layer is electrically conductively connected to the associated connection layer, and wherein the front-side contact layer is freely accessible.
27. The component composite according to claim 19, wherein the connection layer is in direct physical and electrical contact with the sacrificial layer.
28. The component composite according to claim 19, wherein the connection layer is covered by an electrically insulating boundary layer, and wherein the boundary layer is arranged between the connection layer and the sacrificial layer and has an opening in which the connection layer is in direct electrical contact with the sacrificial layer.
29. The component composite according to claim 19, wherein in plan view, the connection layer is completely covered by an electrically insulating boundary layer, wherein the boundary layer is arranged between the connection layer and the sacrificial layer, and wherein an electrically conductive bonding layer is laterally adjacent to the connection layer, is at least partially non-covered by the boundary layer, and thus electrically conductively connects the connection layer to the sacrificial layer.
30. The component composite according to claim 19, wherein the connection layer is completely covered by an electrically conductive boundary layer, and wherein the electrically conductive boundary layer is directly adjacent to the connection layer and directly adjacent to the sacrificial layer.
31. The component composite according to claim 19, wherein the sacrificial layer is a doped Si-, Ge- or Mo-layer.
32. The component composite according to claim 19, wherein the connection layer is a metal layer.
33. The component composite according to claim 19, wherein the connection layer is formed from a transparent electrically conductive material.
34. The component composite according to claim 19, wherein the components are optoelectronic components or micro-LEDs.
35. A method for producing or probing components at wafer level, the method comprising: providing a component composite with an auxiliary carrier, a plurality of components and an electrically conductive sacrificial layer, wherein each of the components has a connection layer which faces the sacrificial layer and is electrically conductively connected to the sacrificial layer, wherein the sacrificial layer is arranged in vertical direction between the auxiliary carrier and the components, and wherein the sacrificial layer is formed to be removable; and probing the components, wherein the auxiliary carrier is a wafer substrate, and wherein the components are electrically connected via the sacrificial layer while the components remain mechanically connected to the auxiliary carrier; or removing the sacrificial layer to form cavities between the auxiliary carrier and the components, wherein the components are mechanically connected to the auxiliary carrier only via a retaining structure, and wherein the retaining structure is arranged in the vertical direction between the auxiliary carrier and the components, and selectively separating the components from the auxiliary carrier to produce the components by selectively separating or detaching the respective components from the retaining structure.
36. The method according to claim 35, further comprising: fixing the component composite to a further auxiliary carrier, wherein the components are arranged between the auxiliary carrier and the further auxiliary carrier; removing the auxiliary carrier so that the components are mechanically supported only by the further auxiliary carrier; and separating the components from the further auxiliary carrier.
37. A component composite comprising: an auxiliary carrier; a plurality of components; a retaining structure; and an electrically conductive sacrificial layer, wherein each of the components has a connection layer which faces the sacrificial layer and is electrically conductively connected to the sacrificial layer, wherein the sacrificial layer is arranged in vertical direction between the auxiliary carrier and the components, wherein the sacrificial layer is formed to be removable and the components are mechanically connected to the auxiliary carrier only via the retaining structure in addition to the sacrificial layer, wherein, in plan view, the connection layer is completely covered by an electrically insulating boundary layer, wherein the boundary layer is arranged between the connection layer and the sacrificial layer, and wherein an electrically conductive bonding layer is laterally adjacent to the connection layer, is at least partially non-covered by the boundary layer and thus electrically conductively connects the connection layer to the sacrificial layer.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] Further embodiments and further developments of the component composite or of the method for characterizing or for producing the components will be apparent from the exemplary embodiments explained below in connection with
[0038]
[0039]
[0040]
[0041]
[0042]
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0043] Identical, equivalent or equivalently acting elements are indicated with the same reference numerals in the figures. The figures are schematic illustrations and thus not necessarily true to scale. Comparatively small elements and particularly layer thicknesses can rather be illustrated exaggeratedly large for the purpose of better clarification.
[0044]
[0045] The component composite 100 comprises a retaining structure 7S which is arranged in the vertical direction in regions between the auxiliary carrier 90 and the sacrificial layer 6 and in regions between the auxiliary carrier 90 and the components 10. It is possible that the retaining structure 7S is directly adjacent to the sacrificial layer 6 and/or directly adjacent to the components 10. In
[0046] The auxiliary carrier 90 may be a wafer substrate. In particular, the auxiliary carrier 90 is different from a growth substrate on which the components 10 are epitaxially grown. For example, the auxiliary carrier 90 is formed of an electrically conductive material, such as of a metal or a semiconductor material, in particular of a doped semiconductor material. In this case, it is possible that the auxiliary carrier 90 is electrically conductively connected to the component 10 or to the components 10 for instance via the electrically conductive retaining structure 7S and the electrically conductive sacrificial layer 6. Thus, as parts of the component composite 100, the components 10 can already be externally electrically contacted via the auxiliary carrier 90.
[0047] Alternatively, it is possible that the auxiliary carrier 90 is formed from an electrically insulating material or from a semiconductor material. In the component composite 100, the components 10 can be electrically contactable externally via the retaining structure 7S and/or via the sacrificial layer 6. If the retaining structure 7S is formed from an electrically insulating material, the electrically conductive sacrificial layer 6 can be formed to be freely accessible from the outside in places, so that the components 10 can be electrically contacted via the electrically conductive sacrificial layer 6.
[0048] According to
[0049] In the absence of the sacrificial layer 6, the component 10 is preferably mechanically connected to the auxiliary carrier 90 exclusively via the retaining structure 7S. The retaining structure 7S serves as a connecting structure between the auxiliary carrier 90 and the components 10. The retaining structure 7S may be formed exclusively by the bonding layer 7 or exclusively by the bonding layer 7 and the passivation layer 70. In particular, the components 10 are in direct mechanical contact with the retaining structure 7S exclusively in the regions of the retaining elements 71 and/or 72. If the mechanical contact between the component 10 and the associated retaining element 71 or 72 is removed after the sacrificial layer 6 has been removed, the component 10 can be completely removed from the auxiliary carrier 9o.
[0050] The retaining elements 71 or 72 are formed in particular as integral parts of the anchoring layer 7. The retaining elements 71 or 72 and remaining areas of the anchoring layer 7 are in particular formed in one piece and/or from the same material. For example, the anchoring layer 7 with the retaining elements 71 and/or 72 is formed from an electrically conductive material, such as from a metal or from a transparent electrically conductive oxide (TCO). Alternatively, it is possible that the anchoring layer 7 comprising the retaining elements 71 and/or 72 is formed from an electrically insulating material, for instance from an electrically insulating oxide, plastic, adhesive, an epoxy, a thermoset such as benzocyclobutene, benzocyclobutene-based material, in particular a benzocyclobutene-based polymer.
[0051] According to
[0052] For example, the passivation layer 70 has a mean vertical layer thickness between a few nanometers and a few micrometers. For example, the mean vertical layer thickness of the passivation layer 70 is from 3 nm to 3 μm inclusive, in particular from 3 nm to 1 μm inclusive, from 3 nm to 300 nm inclusive, for instance from 10 nm to 100 nm inclusive. The anchoring layer 7 has a mean vertical layer thickness that is in particular at least three times, five times, ten times or at least one hundred times as great as the mean vertical layer thickness of the passivation layer 70. For example, a ratio of the mean vertical layer thickness of the anchoring layer 7 to the mean vertical layer thickness of the passivation layer 70 is from 3 to 1000, 10 to 1000, or from 10 to 100, inclusive. In deviation from the above, it is possible for the anchoring layer 7 to have a lower mean layer thickness than the passivation layer 70. In this case, the passivation layer may be a combination of PVD, CVD and/or ALD layers.
[0053] It is conceivable that the passivation layer 70 is electrically conductive or electrically insulating. In a plan view of the auxiliary carrier 90, the passivation layer 70 can partially or completely cover the anchoring layer 7. In particular, the passivation layer 70 directly adjoins the sacrificial layer 6 and/or directly adjoins the components 10.
[0054] If the retaining structure 7S comprises the passivation layer 70, the detachment of the components 10 from the auxiliary carrier 90 or from the anchoring layer 7 can be carried out in a simplified manner, since the passivation layer 70 is also arranged in particular between the retaining elements 71 and/or 72 and the components 10, and the components 10 can be separated or detached from the thin passivation layer 70 and thus from the retaining elements 71 and/or 72 in a simple manner, for example by using external force. If the retaining structure 7S has such a passivation layer 70, the auxiliary carrier 90 together with the anchoring layer 7 arranged thereon and the retaining elements 71 and/or 72 can be reused without great effort, for example already after removal of possible contamination. However, deviating from
[0055] The sacrificial layer 6 is preferably electrically conductive. In particular, the sacrificial layer 6 is based on silicon, germanium or molybdenum. The electrically conductive material of the sacrificial layer 6 may be of porous form. For example, the sacrificial layer 6 is a highly doped layer, in particular made of a semimetal, or of a highly doped semiconductor layer. In other words, the sacrificial layer may be formed of a semiconductor material or of a semimetal with additional use of dopants. For example, the sacrificial layer 6 is a highly doped Si-, Ge- or Mo-layer.
[0056] Preferably, the sacrificial layer 6 is formed to be removable from the component composite 100, in particular selectively removable. For example, the sacrificial layer 6 can be selectively removed from the component composite 100 by a chemical process, in particular by an etching process, without the layers of the components 10 or of the retaining structure 7S adjacent to the sacrificial layer 6 also being removed. SF6 or XeF2 may be used as the etchant. The layers adjacent to the sacrificial layer 6 may have a higher etch resistance than the sacrificial layer 6. For example, the passivation layer 70 or the anchoring layer 7 may be formed of a material that has a lower etch rate than a material of the sacrificial layer 6 with respect to an etchant such as SF6 or XeF2. The passivation layer 70 or the anchoring layer 7 may thus serve as an etch stop layer or a protective layer.
[0057] The component 10 may be an electrical component, in particular an optoelectronic component 10. For example, the component 10 is a light-emitting diode, in particular a μLED, i.e. an LED with geometric dimensions in the micrometer range, such as from 1 μm to 900 μm inclusive, from 10 μm to 600 μm inclusive, or from 30 μm to 300 μm inclusive, in particular from 1 μm to 100 μm, 1 μm to 30 μm, 1.5 μm to 10 μm, or from 1.5 μm to 8 μm inclusive.
[0058] According to
[0059] An active zone 23 of the component 10 is understood to be an active zone in the semiconductor body 2 which is configured in particular for generating or detecting electromagnetic radiation. During operation of the component 10, the active zone 23 is configured to generate electromagnetic radiation for instance in the ultraviolet, visible or infrared spectral range. For example, the active zone 23 comprises a pn-junction or a collection of quantum structures configured to generate or detect electrical radiation.
[0060] The component 10 has a first electrical contact layer 31 and a second electrical contact layer 32. The contact layers 31 and 32 are assigned to different electrical polarities of the component 10. In particular, the first electrical contact layer 31 is configured for electrically contacting the first semiconductor layer 21. The first contact layer 31 may be formed of a transparent electrically conductive oxide, such as indium tin oxide (ITO). It is also possible that the contact layer 31 comprises Au and/or Ge. The second electrical contact layer 32 is configured for electrically contacting the second semiconductor layer 22 and may be formed of a metal or of a transparent electrically conductive oxide.
[0061] The first contact layer 31 is arranged on a front side of the semiconductor body 2 and is in particular freely accessible from the outside. The second contact layer 32 is arranged on a rear side of the semiconductor body 2 and is in particular not freely accessible from the outside. The component 10 has a connection layer 4 via which the second contact layer 32 can be electrically contacted externally. The connection layer 4 can be formed from an electrically conductive material, for example from a transparent electrically conductive oxide, for example from indium tin oxide (ITO), or from a metal such as aluminum, silver, titanium, rhodium, chromium, gold or platinum.
[0062] The component 10 has an insulating layer 8 which is arranged in regions between the connection layer 4 and the second contact layer 32. The insulating layer 8 is formed, for example, from an electrically insulating oxide or nitride, such as SiO.sub.2. Since the second contact layer 32 covers the semiconductor body 2 only in regions, the insulating layer 8 can cover, in particular completely cover, regions of a rear surface of the semiconductor body 2 that are not covered by the second contact layer 32. The insulating layer 8 has an opening through which the connection layer 4 extends to the second contact layer 32. In particular, the insulating layer 8 directly adjoins the sacrificial layer 6, the semiconductor body 2, the second contact layer 32, the connection layer 4 and/or directly adjoins the retaining structure 7S. In
[0063] The connection layer 4 may be in direct or indirect electrical contact with the second contact layer 32. In particular, the connection layer 4 is covered and/or surrounded by the sacrificial layer 6 such that the connection layer 4 is not freely accessible from the outside in the presence of the sacrificial layer 6. However, the connection layer 4 is electrically conductively connected to the sacrificial layer 6 so that the connection layer 4 and thus the second contact layer 32 can be electrically contacted externally via the electrically conductive sacrificial layer 6.
[0064] For example, the sacrificial layer 6 is freely accessible from the outside in places. It is also possible that the electrical contact to the sacrificial layer 6 is led out laterally to an edge region of the auxiliary carrier 90 or to the anchoring layer 7, for example via a conductor track or via a metallic reinforcement. In this case, the auxiliary carrier may be formed of an electrically insulating material or of a poorly conducting material such as glass or sapphire, or of a semiconductor material such as Si or Ge.
[0065] Furthermore, it is possible for the external electrical contacting of the sacrificial layer 6 to be made throughout the anchoring layer 7 or throughout the auxiliary carrier 90. For this purpose, vias may be formed extending throughout the anchoring layer 7 and the auxiliary carrier 90. As an alternative, the anchoring layer 7 and/or the auxiliary carrier 90 may/can be electrically conductive. For example, the anchoring layer 7 is formed from an electrically conductive oxide. The auxiliary carrier 90 may be formed from a semimetal or from a metallic material or from a semiconductor material, in particular from doped semiconductor material.
[0066] The component 10 has a front side ii and a rear side 12. In particular, the component 10 is spatially bounded along the vertical direction by the front side ii and by the rear side 12. In other words, the front side ii and the rear side 12 define outer limits of the spatial extent of the component 10 along the vertical direction.
[0067] The component 10 has side surfaces 13 that are formed, in particular, at an oblique angle. For example, the side surfaces 13 form with the main extension surface of the first contact layer 31 or with the front side 11 an internal obtuse angle which is, for example, between 95° and 135° inclusive, for instance between 95° and 120° inclusive. The side surfaces 13 of the component 10 may be formed mainly by side surfaces of the semiconductor body 2. In sectional view, the semiconductor body 2 has the shape in particular of a trapezoid. Deviating from
[0068] According to
[0069] The exemplary embodiment of a component composite 100 shown in
[0070] For example, at least 0.1%, 0.3%, 0.6%, 1%, 3%, 5% or 10% and at most 30%, 25% or 20%, 10%, 5%, 1% of the total area of the respective rear side 12 adhere to the retaining element or elements 71 and/or 72. For example, a proportion of the area of the retaining elements 71 and/or 72 is between 0.1% and 5% inclusive, between 0.1% and 1% inclusive, for instance between 0.4% and 0.6% inclusive. It is possible that at least 70%, 75%, 80%, 90%, 95% or 99% of the total area of the respective rear side 12 is directly adjacent to the cavity 6H. After removal of the sacrificial layer 6, the components 10 are mechanically connected to the auxiliary carrier 90 in particular exclusively via the retaining structure 7S. In a subsequent method step, the components 10 can be separated individually or in groups from the retaining structure 7S and thus from the auxiliary carrier 90. For this purpose, the mechanical connection between the component 10 and the associated retaining element 71 or 72 are detachable. The detachment takes place in particular at a common interface between the component 10 and the retaining structure 7S, for example at a common interface between the insulating layer 8 and the passivation layer 70 or at a common interface between the insulating layer 8 and the anchoring layer 7. Deviating from this, it is possible that the component composite boo is free of a retaining structure 7S.
[0071] The insulating layer 8, the passivation layer 70 and/or the anchoring layer 7 can be formed as separate layers, in particular from different materials. This facilitates the detachment of the components 10 from the retaining structure 7S. It is possible that the detached components 10 are free of residues or traces of the retaining structure 7S. However, it is also conceivable that the detached components 10 have residues and/or traces of the retaining structure 7S or the retaining elements 72 or 72, in particular on the rear sides 12. Alternatively, the insulating layer 8, the passivation layer 70 and/or the anchoring layer 7 may be formed from the same material. For example, the retaining structure 7S is formed from a combination of SiO.sub.2 layers or TCO layers, with the SiO.sub.2 layers or the TCO layers being deposited on top of each other. The TCO layers may be indium tin oxide layers.
[0072] The exemplary embodiment of a component composite 100 shown in
[0073] According to
[0074] The exemplary embodiment of a component composite 100 shown in
[0075] The exemplary embodiment of a component composite 100 shown in
[0076] According to
[0077] The exemplary embodiment of a component composite 100 shown in
[0078] The exemplary embodiment of a component composite 100 shown in
[0079] The exemplary embodiment of a component composite 100 shown in
[0080] The exemplary embodiment of a component composite 100 shown in
[0081] According to the exemplary embodiments shown in
[0082] According to
[0083] Deviating from
[0084] In all exemplary embodiments described so far, the anchoring layer 7 may be electrically insulating. In particular, the anchoring layer 7 is based on benzocyclobutene (BCB) or is formed from this material. Alternatively, the anchoring layer 7 may be formed from an electrically insulating adhesive, epoxies, thermosets, a transparent electrically conductive oxide, or a metal. The auxiliary carrier 90 may be electrically conductive and formed of a metal. The components 10 can be electrically contacted externally on the rear side via the auxiliary carrier 90 or via the anchoring layer 7.
[0085] The exemplary embodiments of a component composite 100 shown in FIG.s 3F and 3G substantially correspond to the exemplary embodiments shown in
[0086] Another form of retaining elements of the retaining structure 7S is schematically shown in
[0087] As further differences to
[0088] The exemplary embodiment shown in
[0089] The exemplary embodiment of a component composite 100 shown in
[0090] The exemplary embodiment shown in
[0091] The exemplary embodiment shown in
[0092] The exemplary embodiment shown in
[0093] The exemplary embodiment shown in
[0094] The exemplary embodiment shown in
[0095]
[0096] The invention is not restricted to the exemplary embodiments by the description of the invention made with reference to the exemplary embodiments. The invention rather comprises any novel feature and any combination of features, including in particular any combination of features in the claims, even if this feature or this combination is not itself explicitly indicated in the patent claims or exemplary embodiments.