SEMICONDUCTOR LIGHT-EMITTING DEVICE AND METHOD FOR MANUFACTURING THE SAME
The disclosed invention relates to a semiconductor light-emitting element comprising: a plurality of semiconductor layers which are provided with a growth substrate eliminating surface on the side where a first semiconductor layer is located; a support substrate which is provided with a first electrical pathway and a second electrical pathway; a joining layer which joins a first surface side of the support substrate with a second semiconductor layer side of the plurality of semiconductor layers, and is electrically linked with the first electrical pathway; a joining layer eliminating surface which is formed on the first surface, and in which the second electrical pathway is exposed, and which is open towards the plurality of semiconductor layers; and an electrical link for electrically linking the plurality of semiconductor layers with the second electrical pathway exposed in the joining layer eliminating surface.
The present disclosure relates generally to a semiconductor light emitting device or element and a method for manufacturing the same. More specifically, the present disclosure related to a semiconductor light emitting device having electrical passes on a supporting substrate, and a method for manufacturing the same.
Within the context herein, the term “semiconductor light emitting device” is intended to refer to a semiconductor light emitting device that generates light via electron-hole recombination, and the typical example thereof is a group III-nitride semiconductor light emitting device. The group III-nitride semiconductor is composed of Al(x)Ga(y)In(1-x-y)N (wherein, 0≦x≦1, 0≦y≦1, 0≦x+y≦1). Another example thereof is a GaAs-based semiconductor light emitting device used for red light emission.
BACKGROUNDThis section provides background information related to the present disclosure which is not necessarily prior art.
However, because the above process needs to be performed at the chip level, the process gets lengthy and complicated, and the alignment of the electrode films 901, 902 and 903, the electrode 800, and the electrode patterns 1010 and 1020 also creates difficulties. Apart from that, an increase in costs associated with the phosphor coating at the chip level adds another problem.
Therefore, while the commercialization of TFFC (Thin Film Flip Chip) technology at the chip level represents a high level manufacturing technology of semiconductor light emitting devices, on the other hand, it also openly manifests that the application of such technology at the wafer level is not yet made easy. Many suggestions have been made in order to apply this concept at the wafer level. Nevertheless, neither a semiconductor light emitting device nor a method for manufacturing the same was proposed, which can substantially overcome the difficulties in the alignment of electrode films 901, 902 and 903, the electrode 800 and the electrode patterns 1010 and 1020 and, after a wafer level bonding operation, the cracks in the semiconductor layers 200, 300 and 400 during the removal of the substrate 100 and in the subsequent processes.
TECHNICAL PROBLEMThe problems to be solved by the present disclosure will be described in the latter part of the best mode for carrying out the invention.
SUMMARYThis section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.
According to one aspect of the present disclosure, there is provided a semiconductor light emitting device, which comprises a plurality of semiconductor layers that grows sequentially on a growth substrate, with the plurality of semiconductor layers including a first semiconductor layer having a first conductivity and a growth substrate-removed surface being formed on the side thereof, a second semiconductor layer having a second conductivity different from the first conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer, generating light via electron-hole recombination; a supporting substrate having a first surface and a second surface opposite to the first surface, wherein a first electrical pass via which either electrons or holes are transferred to the plurality of semiconductor layers, and a second electrical pass via which either electrons or holes whichever have not been transferred via the first electrical pass are transferred to the plurality of semiconductor layers continue from the second surface to the first surface; a bonded layer, which bonds the second semiconductor layer side of the plurality of semiconductor layers to the first surface side of the supporting substrate and is electrically connected with the first electrical pass; a bonded layer-removed surface formed on the first surface, exposing the second electrical pass and being open towards the plurality of semiconductor layer; and an electrical connection for electrically connecting the plurality of semiconductor layers with the second electrical pass exposed on the bonded layer-removed surface such that either electrons or holes whichever have not been transferred via the first electrical pass are transferred to the plurality of semiconductor layers.
According to another aspect of the present disclosure, there is provided a method for manufacturing a semiconductor light emitting device, comprising the steps of: preparing a plurality of semiconductor layers that grows sequentially on a growth substrate, with the plurality of semiconductor layers including a first semiconductor layer having a first conductivity and a growth substrate-removed surface being formed on the side thereof, a second semiconductor layer having a second conductivity different from the first conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer, generating light via electron-hole recombination; preparing a supporting substrate having a first surface and a second surface opposite to the first surface, wherein a first electrical pass via which either electrons or holes are transferred to the plurality of semiconductor layers, and a second electrical pass via which either electrons or holes whichever have not been transferred via the first electrical pass are transferred to the plurality of semiconductor layers are provided; bonding the plurality of semiconductor layers side on the opposite side of the growth substrate with the first surface side of the supporting substrate, such that a bonded layer is formed on the bonded region and the first electrical pass is electrically connected to the plurality of semiconductor layers via the bonded layer; removing the substrate; removing the bonded layer so as to expose the second electrical pass; and electrically connecting the second electrical pass with the plurality of semiconductor layer such that either electrons or holes whichever have not been transferred via the first electrical pass are transferred to the plurality of semiconductor layers.
Advantageous EffectsThe advantageous effects of the present disclosure will be described in the latter part of the best mode for carrying out the invention.
Hereinafter, the present disclosure will now be described in detail with reference to the accompanying drawings.
As the plurality of semiconductor layers 30, 40 and 50 is removed, the first conductive layer 94 is exposed and electrically connected with the electrical connection 93. The first conductive layer 94 preferably consists of a material which not only spreads current into the second semiconductor layer 50 but also reflects light generated in the active layer 40 towards the first semiconductor layer 30. The first conductive layer 94 can be formed of Au, Pt, Ag, Al, Rh, Cr, Cu, Ta, Ni, Pd, Mg, Ru, Ir, Ti, V, Mo, W, TiW, CuW, ITO, ZnO, SnO2, In2O3, or an alloy thereof, in a multi-layer (e.g. at least two layer) configuration.
The electrical connection 93 can be formed of Au, Pt, Ag, Al, Rh, Cr, Cu, Ta, Ni, Pd, Mg, Ru, Ir, Ti, V, Mo, W, TiW, CuW or an alloy thereof, in a multi-layer (e.g. at least two layer) configuration.
The bonded layer 90 includes a conductive bonded layer 96 provided onto a supporting substrate 101, and a second conductive layer 95 provided on the side of the plurality of semiconductor layer 30, 40 and 50 and continuing to the first semiconductor layer 30 passing through the second semiconductor layer 50 and the active layer 30. The conductive bonded layer 95 may be comprised of a single material, or have another suitable material for bonding on the side abutting against the conductive bonded layer 96.
The conductive bonded layer 95 may be composed of any material(s) forming Ohmic contact with GaN materials and any material(s) serving as a bond, and can be formed of Au, Pt, Ag, Al, Rh, Cu, Ta, Ni, Pd, Ti, V, Mo, W, TiW, CuW, Sn, In, Bi, or an alloy thereof, in a multi-layer (e.g. at least two layer) configuration.
The conductive bonded layer 96 may be composed of any material(s) of excellent adhesion with the supporting substrate and any material(s) serving as a bond, and can be formed of Ti, Ni, W, Cu, Ta, V, TiW, CuW, Au, Pd, Sn, In, Bi, or an alloy thereof, in a multi-layer (e.g. at least two layer) configuration.
Reference numeral 110 and 111 denote insulating layers.
With the above configuration, the entire surfaces of the plurality of semiconductor layers 30, 40 and 50 and the entire surface of the supporting substrate 101 are used for bonding, and these entire surfaces remain in the bonded state even during the removal of the growth substrate 10 (see
Herein below, there will be explained a variety of embodiments of the present disclosures.
(1) A semiconductor light emitting device, comprising: a plurality of semiconductor layers that grows sequentially on a growth substrate, with the plurality of semiconductor layers including a first semiconductor layer having a first conductivity and a growth substrate-removed surface formed on the side thereof, a second semiconductor layer having a second conductivity different from the first conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer, generating light via electron-hole recombination; a supporting substrate having a first surface and a second surface opposite to the first surface, wherein a first electrical pass via which either electrons or holes are transferred to the plurality of semiconductor layers, and a second electrical pass via which either electrons or holes whichever have not been transferred via the first electrical pass are transferred to the plurality of semiconductor layers continue from the second surface to the first surface; a bonded layer, which bonds the second semiconductor layer side of the plurality of semiconductor layers to the first surface side of the supporting substrate and is electrically connected with the first electrical pass; a bonded layer-removed surface formed on the first surface, exposing the second electrical pass and being open towards the plurality of semiconductor layer; and an electrical connection for electrically connecting the plurality of semiconductor layers with the second electrical pass exposed on the bonded layer-removed surface such that either electrons or holes whichever have not been transferred via the first electrical pass are transferred to the plurality of semiconductor layers. Here, the bonded layer means a layer formed after bonding, not any layer to be bonded before bonding which is formed either of the plurality of semiconductors or the supporting substrate.
(2) A semiconductor light emitting device, wherein the first electrical pass is electrically connected to the first semiconductor layer via the bonded layer, and the second electrical pass is electrically connected to the second semiconductor layer via the electrical connection.
(3) A semiconductor light emitting device, further comprising: a first conductive layer which is exposed upon the removal of the plurality of semiconductor layers for connection with the electrical connection, and is electrically connected to the second semiconductor layer. Here, the first conductive layer can be only metal(s) (for examples: Ag, Ni, Ag/Ni) or metal(s) with any metal oxide(s) (for examples: ITO). It usually a reflection function and can be used in combination with a non-conductive structure such as ODR and/or DBR.
(4) A semiconductor light emitting device, wherein the first electrical pass is electrically connected to the second semiconductor layer via the bonded layer, and the second electrical pass is electrically connected to the first semiconductor layer via the electrical connection.
(5) A semiconductor light emitting device, further comprising: a second conductive layer which is exposed upon the removal of the plurality of semiconductor layers for connection with the electrical connection, and is electrically connected to the first semiconductor layer. Here, the second conductive layer functions to supply electricity to the first semiconductor layer and can be used as a part of the bonded layer.
(6) A semiconductor light emitting device, wherein the plurality of semiconductor layers are all covered by the bonded layer, when projected in a direction from the plurality of semiconductor layers to the supporting substrate.
(7) A semiconductor light emitting device, further comprising: an electric contact which is exposed on the opposite side of the supporting substrate with respect to the bonded layer, and interworks with the electrical connection for use in probing of the semiconductor light emitting device.
(8) A method for manufacturing a semiconductor light emitting device, comprising the steps of: preparing a plurality of semiconductor layers that grows sequentially on a growth substrate, with the plurality of semiconductor layers including a first semiconductor layer having a first conductivity and a growth substrate-removed surface being formed on the side thereof, a second semiconductor layer having a second conductivity different from the first conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer, generating light via electron-hole recombination; preparing a supporting substrate having a first surface and a second surface opposite to the first surface, wherein a first electrical pass via which either electrons or holes are transferred to the plurality of semiconductor layers, and a second electrical pass via which either electrons or holes whichever have not been transferred via the first electrical pass are transferred to the plurality of semiconductor layers are provided; bonding the plurality of semiconductor layers side on the opposite side of the growth substrate with the first surface side of the supporting substrate, such that a bonded layer is formed on the bonded region and the first electrical pass is electrically connected to the plurality of semiconductor layers via the bonded layer; removing the substrate; removing the bonded layer so as to expose the second electrical pass; and electrically connecting the second electrical pass with the plurality of semiconductor layer such that either electrons or holes whichever have not been transferred via the first electrical pass are transferred to the plurality of semiconductor layers.
(9) A method for manufacturing a semiconductor light emitting device, wherein the bonded layer removing step includes removing the plurality of semiconductor layers.
(10) A method for manufacturing a semiconductor light emitting device, wherein the step of removing the bonded layer includes isolating the plurality of semiconductor layers for producing individual chips, and removing the bonded layer to expose the second electrical pass.
(11) A method for manufacturing a semiconductor light emitting device, wherein the plurality of semiconductor layers has a conductive layer electrically connected to one of the first and second semiconductor layers, and the method further comprises, prior to the electrical connecting step, the step of removing the plurality of semiconductor layers to expose the conductive layer.
(12) A method for manufacturing a semiconductor light emitting device, wherein the conductive layer is electrically connected to the second semiconductor layer.
(13) A method for manufacturing a semiconductor light emitting device, wherein the conductive layer is electrically connected to the first semiconductor layer.
(14) A method for manufacturing a semiconductor light emitting device, wherein in the electrical connecting step, the second electrical pass continues to the plurality of semiconductor layers having the growth substrate been removed therefrom.
(15) A method for manufacturing a semiconductor light emitting device, wherein prior to the bonding step, a part of the plurality of semiconductor layers is removed.
(16) A method for manufacturing a semiconductor light emitting device, wherein in the bonding step, both the first electrical pass and the second electrical pass are bonded to the bonded layer.
(17) A method for manufacturing a semiconductor light emitting device, wherein in the bonding step, the bonded layer is formed all over the first surface of the supporting substrate.
A semiconductor light emitting device and a method for manufacturing the same according to the present disclosure make it possible to obtain a TFFC (Thin Film Flip Chip)-type semiconductor light emitting device.
Another semiconductor light emitting device and a method for manufacturing the same according to the present disclosure make it possible to obtain a TFFC-type semiconductor light emitting device at the wafer level.
Yet another semiconductor light emitting device and a method for manufacturing the same according to the present disclosure make it possible to accomplish a higher productivity without suffering from cracking of many semiconductor layers during the removal process of a growth substrate as well as in the processes after the removal.
Yet another semiconductor light emitting device and a method for manufacturing the same according to the present disclosure make it possible to accomplish a wafer-level TFFC-type semiconductor light emitting device featuring an easier alignment of electrodes.
Claims
1. A semiconductor light emitting device, comprising:
- a plurality of semiconductor layers that grows sequentially on a growth substrate, with the plurality of semiconductor layers including a first semiconductor layer having a first conductivity and a growth substrate-removed surface formed on the side thereof, a second semiconductor layer having a second conductivity different from the first conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer, generating light via electron-hole recombination;
- a supporting substrate having a first surface and a second surface opposite to the first surface, wherein a first electrical pass via which either electrons or holes are transferred to the plurality of semiconductor layers, and a second electrical pass via which either electrons or holes whichever have not been transferred via the first electrical pass are transferred to the plurality of semiconductor layers continue from the second surface to the first surface;
- a bonded layer, which bonds the second semiconductor layer side of the plurality of semiconductor layers to the first surface side of the supporting substrate and is electrically connected with the first electrical pass;
- a bonded layer-removed surface formed on the first surface, exposing the second electrical pass and being open towards the plurality of semiconductor layer; and
- an electrical connection for electrically connecting the plurality of semiconductor layers with the second electrical pass exposed on the bonded layer-removed surface such that either electrons or holes whichever have not been transferred via the first electrical pass are transferred to the plurality of semiconductor layers.
2. The semiconductor light emitting device as claimed in claim 1, wherein the first semiconductor layer, the active layer and the second semiconductor layer are Group III-nitride semiconductor light emitting devices.
3. The semiconductor light emitting device as claimed in claim 1, wherein the first electrical pass is electrically connected to the first semiconductor layer via the bonded layer, and the second electrical pass is electrically connected to the second semiconductor layer via the electrical connection.
4. The semiconductor light emitting device as claimed in claim 3, further comprising:
- a first conductive layer which is exposed upon the removal of the plurality of semiconductor layers for connection with the electrical connection, and is electrically connected to the second semiconductor layer.
5. The semiconductor light emitting device as claimed in claim 1, wherein the first electrical pass is electrically connected to the second semiconductor layer via the bonded layer, and the second electrical pass is electrically connected to the first semiconductor layer via the electrical connection.
6. The semiconductor light emitting device as claimed in claim 5, further comprising:
- a second conductive layer which is exposed upon the removal of the plurality of semiconductor layers for connection with the electrical connection, and is electrically connected to the first semiconductor layer.
7. The semiconductor light emitting device as claimed in claim 5, wherein the electrical connection is extended to the growth substrate-removed surface.
8. The semiconductor light emitting device as claimed in claim 1, wherein the plurality of semiconductor layers has a mesa surface formed upon the sequential removal of the second semiconductor layer and the active layer.
9. (canceled)
10. The semiconductor light emitting device as claimed in claim 1, wherein the plurality of semiconductor layers are all covered by the bonded layer, when projected in a direction from the plurality of semiconductor layers to the supporting substrate.
11. The semiconductor light emitting device as claimed in claim 1, further comprising:
- an electric contact which is exposed on the opposite side of the supporting substrate with respect to the bonded layer, and interworks with the electrical connection for use in probing of the semiconductor light emitting device.
12. A method for manufacturing a semiconductor light emitting device, comprising the steps of:
- preparing a plurality of semiconductor layers that grows sequentially on a growth substrate, with the plurality of semiconductor layers including a first semiconductor layer having a first conductivity and a growth substrate-removed surface being formed on the side thereof, a second semiconductor layer having a second conductivity different from the first conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer, generating light via electron-hole recombination;
- preparing a supporting substrate having a first surface and a second surface opposite to the first surface, wherein a first electrical pass via which either electrons or holes are transferred to the plurality of semiconductor layers, and a second electrical pass via which either electrons or holes whichever have not been transferred via the first electrical pass are transferred to the plurality of semiconductor layers are provided;
- bonding the plurality of semiconductor layers side on the opposite side of the growth substrate with the first surface side of the supporting substrate, such that a bonded layer is formed on the bonded region and the first electrical pass is electrically connected to the plurality of semiconductor layers via the bonded layer;
- removing the substrate;
- removing the bonded layer so as to expose the second electrical pass; and
- electrically connecting the second electrical pass with the plurality of semiconductor layer such that either electrons or holes whichever have not been transferred via the first electrical pass are transferred to the plurality of semiconductor layers.
13. The method for manufacturing a semiconductor light emitting device as claimed in claim 12, wherein the bonded layer removing step includes removing the plurality of semiconductor layers.
14. The method for manufacturing a semiconductor light emitting device as claimed in claim 12, wherein the step of removing the bonded layer includes isolating the plurality of semiconductor layers for producing individual chips, and removing the bonded layer to expose the second electrical pass.
15. The method for manufacturing a semiconductor light emitting device as claimed in claim 12, wherein the plurality of semiconductor layers has a conductive layer electrically connected to one of the first and second semiconductor layers, and the method further comprises, prior to the electrical connecting step, the step of removing the plurality of semiconductor layers to expose the conductive layer.
16. The method for manufacturing a semiconductor light emitting device as claimed in claim 15, wherein the conductive layer is electrically connected to the second semiconductor layer.
17. The method for manufacturing a semiconductor light emitting device as claimed in claim 15, wherein the conductive layer is electrically connected to the first semiconductor layer.
18. The method for manufacturing a semiconductor light emitting device as claimed in claim 12, wherein in the electrical connecting step, the second electrical pass continues to the plurality of semiconductor layers having the growth substrate been removed therefrom.
19. The method for manufacturing a semiconductor light emitting device as claimed in claim 12, wherein prior to the bonding step, a part of the plurality of semiconductor layers is removed.
20. (canceled)
21. The method for manufacturing a semiconductor light emitting device as claimed in claim 12, wherein in the bonding step, both the first electrical pass and the second electrical pass are bonded to the bonded layer.
22. The method for manufacturing a semiconductor light emitting device as claimed in claim 12, wherein in the bonding step, the bonded layer is formed all over the first surface of the supporting substrate.
Type: Application
Filed: Jun 14, 2013
Publication Date: Jul 2, 2015
Inventor: Sang Jeong AN
Application Number: 14/406,906