TWI511326B - Flip chip light-emitting device - Google Patents

Description

Flip-coated light-emitting element

The present invention relates to a light-emitting element, and more particularly to a flip-chip light-emitting element.

The light-emitting diode has advantages such as long life, small volume, high shock resistance, low heat generation, and low power consumption, and thus has been widely used as an indicator or a light source in households and various devices. In recent years, light-emitting diodes have developed toward high power, so their applications have expanded to road lighting, large outdoor billboards, traffic lights and related fields. In the future, light-emitting diodes may even become the main source of illumination for both power saving and environmental protection functions.

In general, in order to increase the luminous efficiency of the light-emitting diode, a reflective layer is usually added, wherein the reflective layer is adhered between an epitaxial structure and an electrode through an adhesive layer. However, the use of the adhesive layer affects the reflection efficiency between the epitaxial structure and the reflective layer, thereby reducing the luminous efficiency of the overall light-emitting diode, and the adhesive layer also affects the electrical conduction efficiency between the epitaxial structure and the electrode. Therefore, how to effectively improve the luminous efficiency of the light-emitting diode without affecting the electrical conduction efficiency of the light-emitting diode has become one of the problems that need to be solved at present.

The invention provides a flip-chip light-emitting element, which can improve the overall luminous efficiency.

The present invention provides a flip-chip light-emitting device comprising a substrate, a first type semiconductor layer, a light-emitting layer, a second type semiconductor layer, a first electrode, a second electrode, a transparent conductive layer, and a plurality of Reflecting particles. The substrate has an upper surface, the first semiconductor layer is disposed on the upper surface of the substrate, the light emitting layer is disposed on the first semiconductor layer, the second semiconductor layer is disposed on the light emitting layer, and the first electrode is disposed on the first semiconductor layer The second electrode is disposed on the second type semiconductor layer, and the transparent conductive layer is disposed between the second electrode and the second type semiconductor layer, wherein the transparent conductive layer and the second electrode have a contact interface. The reflective particles are distributed at least on the contact interface and are electrically connected to the second electrode and the transparent conductive layer.

In an embodiment of the invention, the material of the second electrode is at least one metal selected from the group consisting of silver, aluminum, platinum, gold, nickel, and chromium.

In an embodiment of the invention, the material of the reflective particles is the same as the material of the second electrode.

In an embodiment of the invention, the particle size of each of the reflective particles is between 1 nm and 500 nm.

In an embodiment of the invention, the reflective particles are at least distributed on the contact interface by sputtering, bombardment, collision, implantation, embedding, diffusion or reaction.

In an embodiment of the invention, the orthogonal projection area of the second electrode on the substrate is equal to the orthographic projection area of the transparent conductive layer on the substrate.

In an embodiment of the invention, the reflective particles are more distributed in the second electrode, in the transparent conductive layer or in the second electrode and the transparent conductive layer.

In an embodiment of the invention, the second electrode is on the substrate The orthographic projection area is larger than the orthographic projection area of the transparent conductive layer on the substrate.

In an embodiment of the invention, the reflective particles are more distributed in the second electrode, in the transparent conductive layer or in the second electrode and the transparent conductive layer.

In an embodiment of the invention, the reflective particles are more distributed in the second type semiconductor layer, on the contact interface of the second type semiconductor layer and the second electrode, or in the second type semiconductor layer and the second type semiconductor layer On the contact interface of the second electrode.

In an embodiment of the invention, the material of the transparent conductive layer is composed of at least two materials having different conductivity.

In an embodiment of the invention, the flip-chip light-emitting device further includes an insulating layer covering at least a portion of the transparent conductive layer, a portion of the second-type semiconductor layer, a portion of the light-emitting layer, and a portion of the first-type semiconductor layer, wherein the second The electrode covers the transparent conductive layer and a portion of the insulating layer.

In an embodiment of the invention, the reflective particles are more distributed in the second electrode, in the transparent conductive layer or in the second electrode and the transparent conductive layer.

In an embodiment of the invention, the reflective particles are more distributed in the insulating layer, on the contact interface between the insulating layer and the second electrode, or in the insulating layer, and on the contact interface between the insulating layer and the second electrode.

In an embodiment of the invention, the insulating layer extends over a portion of the upper surface of the substrate.

In an embodiment of the invention, the insulating layer comprises a single layer or a plurality of layers, and the material of the insulating layer is selected from the group consisting of alumina, yttria, tantalum nitride, tantalum carbide and aluminum nitride, and combinations thereof. Ethnic group.

Based on the above, since the flip-chip light-emitting element of the present invention has at least The reflective particles are disposed on the contact interface between the transparent conductive layer and the second electrode, and the reflective particles, the second electrode, and the transparent conductive layer are electrically connected. Therefore, compared with the conventional light-emitting diode in which a reflective layer is adhered between the epitaxial structure and the electrode through the adhesive layer, the flip-chip light-emitting element of the present invention replaces the adhesive layer with reflective particles, so there is no need to set The adhesive layer and the reflective particles can obtain better reflection effect, scattering effect and conductivity, thereby improving the luminous efficiency and electrical conduction of the integrated flip-chip light-emitting element.

The above described features and advantages of the present invention will be more apparent from the following description.

1 is a cross-sectional view showing a flip chip type light emitting device according to an embodiment of the present invention. Referring to FIG. 1 , the flip-chip light emitting device 100 a of the present embodiment includes a substrate 110 , a first semiconductor layer 120 , a light emitting layer 130 , a second semiconductor layer 140 , a first electrode 150 , and a second The electrode 160a, a transparent conductive layer 170a, and a plurality of reflective particles 180a.

In detail, the substrate 110 has an upper surface 112, the first type semiconductor layer 120 is disposed on the upper surface 112 of the substrate 110, the light emitting layer 130 is disposed on the first type semiconductor layer 120, and the second type semiconductor layer 140 is disposed on the light emitting layer. The first electrode 150 is disposed on the first type semiconductor layer 120, the second electrode 160a is disposed on the second type semiconductor layer 140, and the transparent conductive layer 170a is disposed between the second electrode 160a and the second type semiconductor layer 140. There is a contact interface C1 between the transparent conductive layer 170a and the second electrode 160a. The reflective particles 180a are distributed at least on the contact interface C1 and the second The electrode 160a and the transparent conductive layer 170a are electrically connected.

More specifically, in this embodiment, the material of the second electrode 160a is, for example, at least one metal selected from the group consisting of silver, aluminum, platinum, gold, nickel, and chromium, that is, the second electrode 160a can be Has the effect of reflection. In particular, the material of the reflective particles 180a and the material of the second electrode 160a may be the same, for example, the material of the reflective particles 180a may be silver. The particle diameter of each of the reflective particles 180a is, for example, between 1 nm and 500 nm. Here, the reflective particles 180a may be distributed at least on the contact interface C1 by sputtering, bombardment, collision, implantation, embedding, diffusion, or reaction. As shown in FIG. 1, the reflective particles 180a may be more distributed within the second electrode 160a. Of course, in other embodiments not shown, the reflective particles 180a may be more distributed in the transparent conductive layer 170a or in the second electrode 160a and the transparent conductive layer 170a, which is not limited herein.

Since the material of the reflective particles 180a of the present embodiment can be the same as the material of the second electrode 160a, the reflective particles 180a can have conductivity in addition to the effect of reflection, and the second electrode 160a also has the effects of conduction and reflection. Furthermore, the reflective particles 180a are distributed at least at the contact interface C1 between the transparent conductive layer 170a and the second electrode 160a, that is, the contact interface C1 is a non-flat surface, and thus the light emitted by the light-emitting layer 130 (not shown) In addition to the reflection effect of the reflective particles 180a, the contact interface C1 also causes light to scatter. In this way, the luminous efficiency of the entire flip-chip light-emitting element 100a can be effectively improved.

In addition, the orthographic projection area of the second electrode 160a on the substrate 110 of the embodiment is substantially equal to the front projection of the transparent conductive layer 170a on the substrate 110. A shadow area in which the second electrode 160a and the transparent conductive layer 170a expose a portion of the second type semiconductor layer 140. The material of the transparent conductive layer 170a is composed of, for example, at least two materials having different conductivity, such as indium tin oxide, indium zinc oxide or zinc oxide doped aluminum, but is not limited thereto.

The flip-chip light-emitting element 100a of the present embodiment has reflective particles 180a distributed on at least the contact interface C1 between the transparent conductive layer 170a and the second electrode 160a, and the reflective particles 180a, the second electrode 160a, and the transparent conductive layer 170a. Electrical connection. Therefore, the flip-chip light-emitting device 100a of the present embodiment does not need to be provided with an adhesive layer and can be transmitted through the reflective particles 180a, as compared with the conventional light-emitting diode structure in which the reflective layer is adhered to the light-emitting layer through the adhesive layer. The reflection effect, the scattering effect, and the conductivity are excellent, and the luminous efficiency and electrical conduction of the entire flip-chip light-emitting device 100a can be improved.

It is to be noted that the following embodiments use the same reference numerals and parts of the above-mentioned embodiments, and the same reference numerals are used to refer to the same or similar elements, and the description of the same technical content is omitted. For the description of the omitted portions, reference may be made to the foregoing embodiments, and the following embodiments are not repeated.

2 is a cross-sectional view showing a flip chip type light emitting device according to another embodiment of the present invention. Referring to FIG. 2, the flip-chip light-emitting device 100b of the present embodiment is similar to the flip-chip light-emitting device 100a of FIG. 1 except that the orthographic projection area of the second electrode 160b of the present embodiment on the substrate 110 is greater than The orthographic projection area of the transparent conductive layer 170b on the substrate 110, wherein the second electrode 160b extends to cover a portion of the second type semiconductor layer 140 exposed by the transparent conductive layer 170b. That is, the flip-chip illumination of this embodiment Element 100b can have a larger reflective area. Furthermore, in the present embodiment, as shown in FIG. 2, the reflective particles 180b may be distributed more than the contact interface C1 between the transparent conductive layer 170b and the second electrode 160b, and the reflective particles 180b may be more distributed in the second electrode 160b. On the contact interface C2 with the second electrode 160b and the second type semiconductor layer 140. Of course, in other embodiments not shown, the reflective particles 180b may be more distributed in the second type semiconductor layer 140, in the second type semiconductor layer 140, and the contact interface C2 of the second type semiconductor layer 140 and the second electrode 160b. The combination of the upper and second electrodes 160b, the transparent conductive layer 170b, the second electrode 160b and the transparent conductive layer 170b or the above state is not limited thereto.

3 is a cross-sectional view showing a flip chip type light emitting device according to still another embodiment of the present invention. Referring to FIG. 3, the flip-chip light-emitting device 100c of the present embodiment is similar to the flip-chip light-emitting device 100a of FIG. 1, except that the flip-chip light-emitting device 100c of the present embodiment further includes an insulating layer 190c. The insulating layer 190c covers at least a portion of the transparent conductive layer 170c, a portion of the second type semiconductor layer 140, a portion of the light emitting layer 130, and a portion of the first type semiconductor layer 120c. In particular, the second electrode 160c covers the transparent conductive layer 170c and the partial insulating layer 190c, that is, the orthographic projection area of the second electrode 160c on the substrate 110 is larger than the orthographic projection area of the transparent conductive layer 170c on the substrate 110. Therefore, the flip-chip light-emitting element 100c of the present embodiment can have a large reflective area. Furthermore, in the present embodiment, as shown in FIG. 3, in addition to the reflective particles 180c distributed over the contact interface C1 between the transparent conductive layer 170c and the second electrode 160c, the reflective particles 180c may be more distributed over the insulating layer 190c and the first The contact interface C3 of the two electrodes 160c. Of course, the other is not shown In the embodiment, the reflective particles 180c may be distributed in the second electrode 160c, in the transparent conductive layer 170c, in the second electrode 160c and the transparent electrode 170c, in the insulating layer 190c, in the insulating layer 190c, and in the insulating layer 190c and the second electrode. The combination of the contact interface C3 of 160c or the above state is not limited herein. In addition, the insulating layer 190c of the embodiment includes, for example, at least one single layer or a plurality of layers, and the material of the insulating layer is selected from the group consisting of alumina, yttria, tantalum nitride, tantalum carbide, and aluminum nitride, and combinations thereof. The luminous efficiency of the entire flip-chip light-emitting element 100c can be effectively improved. Herein, the insulating layer 190c can be disposed in addition to the second electrode 160c to increase the reflective area, and the second electrode 160c and the first electrode 150 can also have better electrical insulation effect. .

4 is a cross-sectional view showing a flip chip type light emitting device according to still another embodiment of the present invention. Referring to FIG. 4, the flip-chip light-emitting device 100d of the present embodiment is similar to the flip-chip light-emitting device 100c of FIG. 3, except that the insulating layer 190d of the present embodiment extends over a portion of the upper surface 112 of the substrate 110. That is, the insulating layer 190d covers a portion of the transparent conductive layer 170d, a portion of the second type semiconductor layer 140, a portion of the light emitting layer 130, a portion of the first type semiconductor layer 120, and a portion of the upper surface 112 of the substrate 110. Here, the insulating layer 190d is disposed in addition to the second electrode 160d across the insulating layer 190d to increase the reflective area, and the second electrode 160d and the first electrode 150 are preferably electrically insulated. .

In summary, the flip-chip light-emitting device of the present invention has reflective particles distributed at least at a contact interface between the transparent conductive layer and the second electrode, and the reflective particles, the second electrode, and the transparent conductive layer are electrically connected. because Therefore, compared with the conventional light-emitting diode in which a reflective layer is adhered between the epitaxial structure and the electrode through the adhesive layer, the flip-chip light-emitting element of the present invention replaces the adhesive layer with reflective particles, so there is no need to set The adhesive layer and the reflective particles can obtain better reflection effect, scattering effect and conductivity, thereby improving the luminous efficiency and electrical conduction of the integrated flip-chip light-emitting element.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100a, 100b, 100c, 100d‧‧‧ flip-chip light-emitting elements

110‧‧‧Substrate

112‧‧‧ upper surface

120‧‧‧First type semiconductor layer

130‧‧‧Lighting layer

140‧‧‧Second type semiconductor layer

150‧‧‧first electrode

160a, 160b, 160c, 160d‧‧‧ second electrode

170a, 170b, 170c, 170d‧‧‧ transparent conductive layer

180a, 180b, 180c, 180d‧‧‧ reflection particles

190c, 190d‧‧‧ insulation

C1, C2, C3‧‧‧ contact interface

1 is a cross-sectional view showing a flip chip type light emitting device according to an embodiment of the present invention.

2 is a cross-sectional view showing a flip chip type light emitting device according to another embodiment of the present invention.

3 is a cross-sectional view showing a flip chip type light emitting device according to still another embodiment of the present invention.

4 is a cross-sectional view showing a flip chip type light emitting device according to still another embodiment of the present invention.

100a‧‧‧Flip-chip illuminating element

110‧‧‧Substrate

112‧‧‧ upper surface

120‧‧‧First type semiconductor layer

130‧‧‧Lighting layer

140‧‧‧Second type semiconductor layer

150‧‧‧first electrode

160a‧‧‧second electrode

170a‧‧‧Transparent conductive layer

180a‧‧‧Reflecting particles

C1‧‧‧ contact interface

Claims (16)

A flip-chip light-emitting device comprising: a substrate having an upper surface; a first-type semiconductor layer disposed on the upper surface of the substrate; a light-emitting layer disposed on the first-type semiconductor layer; a type of semiconductor layer disposed on the light emitting layer; a first electrode disposed on the first type semiconductor layer; a second electrode disposed on the second type semiconductor layer; and a transparent conductive layer disposed on the first layer Between the two electrodes and the second type semiconductor layer, wherein the transparent conductive layer and the second electrode have a contact interface; and a plurality of reflective particles are distributed at least on the contact interface and the second electrode and the The transparent conductive layer is electrically connected. The flip-chip light-emitting device of claim 1, wherein the material of the second electrode is at least one metal selected from the group consisting of silver, aluminum, platinum, gold, nickel, and chromium. The flip-chip light-emitting device according to claim 1, wherein the material of the reflective particles is the same as the material of the second electrode. The flip-chip light-emitting device according to claim 1, wherein each of the reflective particles has a particle diameter of between 1 nm and 500 nm. The flip-chip light-emitting device of claim 1, wherein the reflective particles are distributed at least on the contact interface by sputtering, bombardment, collision, implantation, embedding, diffusion or reaction. A flip-chip type light-emitting element according to claim 1, wherein The orthographic projection area of the second electrode on the substrate is equal to the orthographic projection area of the transparent conductive layer on the substrate. The flip-chip light-emitting device of claim 6, wherein the reflective particles are more distributed in the second electrode, in the transparent conductive layer or in the second electrode and the transparent conductive layer. The flip-chip light-emitting device of claim 1, wherein an orthographic projection area of the second electrode on the substrate is larger than an orthographic projection area of the transparent conductive layer on the substrate. The flip-chip light-emitting device of claim 8, wherein the reflective particles are more distributed in the second electrode, in the transparent conductive layer or in the second electrode and the transparent conductive layer. The flip-chip light-emitting device of claim 8 or claim 9, wherein the reflective particles are more distributed in the second semiconductor layer, and the contact interface between the second semiconductor layer and the second electrode And in the second type semiconductor layer and the contact interface of the second type semiconductor layer and the second electrode. The flip-chip light-emitting device according to claim 1, wherein the material of the transparent conductive layer is composed of at least two materials having different conductivity. The flip-chip light-emitting device of claim 1, further comprising an insulating layer covering at least a portion of the transparent conductive layer, a portion of the second semiconductor layer, a portion of the light-emitting layer, and a portion of the first-type semiconductor layer Wherein the second electrode covers the transparent conductive layer and a portion of the insulating layer. A flip-chip illuminator as described in claim 12 And the reflective particles are more distributed in the second electrode, in the transparent conductive layer or in the second electrode and the transparent conductive layer. The flip-chip light-emitting device of claim 12, wherein the reflective particles are more distributed in the insulating layer, at a contact interface between the insulating layer and the second electrode, or the insulating layer And a contact interface between the insulating layer and the second electrode. The flip-chip light-emitting device of claim 12, wherein the insulating layer further extends over a portion of the upper surface of the substrate. The flip-chip light-emitting device according to claim 12, wherein the insulating layer comprises at least one single layer or a plurality of layers, and the insulating layer is made of a material selected from the group consisting of alumina, cerium oxide, cerium nitride, cerium carbide and nitrogen. A group of aluminum and its combination.