TW201340398A - Electrical contact structure of LED - Google Patents

Abstract

The present invention provides an electrical contact structure of LED, which applied to an LED structure. The present invention comprises a N-type metal electrode layer and a nitride middle layer. The LED structure comprises a N-type semiconductor layer stacked to be formed as a sandwich structure, a light emitting layer, and a P-type semiconductor layer, wherein the nitride middle layer is patterned to be formed on the N-type semiconductor layer. The N-type metal electrode layer is formed on the nitride middle layer, so as to form a barrier interface by the nitride middle layer, which may prevent the N-type semiconductor layer from damaging by the diffusion of metal ions and maintain the electrical stability; and, the nitride middle layer will not be softened and condensed under high temperature for a long time, so as to enhance the adhesion and avoid the occurrence of delamination effect of the N-type metal electrode layer. Thus, the present invention may increase the service life for LED.

Description

Light-emitting diode electrical contact structure

The invention relates to a light-emitting diode, in particular to a light-emitting diode electrical contact structure.

Light Emitting Diode (LED) is mainly composed of multiple epitaxial stacking of semiconductor materials. Taking a blue light emitting diode as an example, it is mainly composed of a III-nitride based epitaxial film.
Please refer to FIG. 1 , which is a conventional vertical light-emitting diode comprising an N-type semiconductor layer 1 , a light-emitting layer 2 and a P-type semiconductor layer 3 constituting a sandwich structure, and the P-type semiconductor layer. A Mirror layer, a buffer layer, a bonding layer 6, a germanium substrate 7 and a P-type electrode 8 are disposed in sequence, and the surface of the N-type semiconductor layer 1 may be a roughening process to increase the light emission rate, and an N-type electrode 9 is provided. Accordingly, after the N-type electrode 9 and the P-type electrode 8 are applied with a voltage, the N-type semiconductor layer 1 supplies electrons, and the P-type The semiconductor layer 3 provides a hole, and the electrons are combined with the hole in the light-emitting layer 2 to generate light.
However, the N-type electrode 9 is generally used, such as silver, aluminum, nickel, etc., which is easily softened and condensed into a spherical shape due to high temperature, which causes the N-type electrode 9 to peel off, and after long-term use, the metal The ions slowly infiltrate into the N-type semiconductor layer 1, thereby causing electrical instability, which shortens the life of the light-emitting diode and cannot meet the demand for long-term use.

The main object of the present invention is to disclose a light-emitting diode electrical contact structure to increase the service life of the light-emitting diode.
The invention relates to a light-emitting diode electrical contact structure, which is applied to a light-emitting diode structure, which comprises an N-type semiconductor layer, a light-emitting layer and a P-type semiconductor layer stacked to form a sandwich structure. The method includes a nitride intermediate layer and an N-type metal electrode layer, wherein the nitride intermediate layer is patterned on the N-type semiconductor layer, and the N-type metal electrode layer is formed on the nitride intermediate layer.
Accordingly, the present invention can form the nitride intermediate layer as a blocking interface by the arrangement of the nitride intermediate layer and by the physical properties of the nitride, and the N-type semiconductor layer can be protected by the blocking interface. The metal ion of the N-type metal electrode layer is prevented from being diffused and destroyed, and the electrical stability is maintained, and the nitride intermediate layer is not softened and condensed into a spherical shape due to high temperature, thereby increasing the adhesion and preventing the N-type metal electrode layer from being peeled off. The phenomenon can increase the service life of the light-emitting diode.

The detailed description of the present invention and the technical description of the present invention are further illustrated by the accompanying drawings, but it should be understood that these embodiments are merely illustrative and not to be construed as limiting.

Referring to FIG. 2A and FIG. 2B, a first embodiment of the present invention is applied to a light emitting diode structure 10 including a nitride intermediate layer 20 and an N-type metal electrode layer. 30. The LED structure 10 includes an N-type semiconductor layer 11 stacked to form a sandwich structure, a light-emitting layer 12 and a P-type semiconductor layer 13. A reflective layer 14 is sequentially disposed under the P-type semiconductor layer 13. A Mirror layer, a buffer layer 15, a bonding layer 16, a germanium substrate 17, and a P-type electrode 18.

The nitride intermediate layer 20 is patterned on the N-type semiconductor layer 11, and the nitride intermediate layer 20 may be selected from the group consisting of aluminum nitride (AlN), titanium nitride (TiN), and chromium nitride (CrN). The group formed, that is, the composition of the nitride intermediate layer 20 is Ti(X)N(1-X), Al(X)N(1-X), Cr(X)N(1-X), And 0.05 < X < 0.15.

In other words, the composition ratio of nitrogen and aluminum of aluminum nitride is X: 1-X, and X is between 0.05 and 0.15. Similarly, the composition ratio of nitrogen, titanium to nitrogen and chromium of titanium nitride and chromium nitride is also X: 1-X, and X is between 0.05 and 0.15, and the thickness of the nitride intermediate layer 20 is The preferred implementation value is from 10 nm to 500 nm, since the nitride can maintain stable physical properties at high temperatures and can block the diffusion of metal ions, thereby forming a barrier by the arrangement of the nitride intermediate layer 20. The interface prevents the light-emitting diode from rapidly aging, and the N-type semiconductor layer 11 may have an irregular surface 111 in a region not having the nitride intermediate layer 20, and the irregular surface 111 can prevent total reflection from being generated to enhance light. The injection rate, and the irregular surface 111 can be formed by a physical method such as plasma impact.

The N-type metal electrode layer 30 is formed on the nitride intermediate layer 20, and the N-type metal electrode layer 30 may be selected from the group consisting of aluminum, titanium, nickel, chromium, platinum, and gold. The thickness of the N-type metal electrode layer 30 is greater than 1 micrometer, and the N-type metal electrode layer 30 may have at least two metal materials interlaced.

The third embodiment of the present invention is shown in FIG. 20 and the N-type metal electrode layer 30 are formed on the irregular surface 111, and the irregular surface 111 may be continuous zigzag, and the irregular surface 111 is adjacent to a peak to peak distance D, Preferably, it is implemented to be greater than 500 nm.

As described above, the present invention, by virtue of the arrangement of the nitride intermediate layer 20, forms Schottky contact with the N-type semiconductor layer, but does not cause a significant increase in the forward operating voltage (Forward Voltage). The nitride intermediate layer 20 can be formed to block the interface, so that the metal ions can be prevented from diffusing and the stable physical properties can be maintained at a high temperature, so that the N-type can be protected by the barrier protection of the nitride intermediate layer 20. The semiconductor layer 11 can be prevented from being diffused and destroyed by metal ions, and remains electrically stable, and the nitride intermediate layer 20 is not softened and condensed into a spherical shape due to high temperature, and the adhesion can be maintained, thereby preventing the N-type metal electrode layer 30 from being peeled off. Phenomenon, according to the present invention, can increase the service life of the light-emitting diode to meet the demand.

The above are only the preferred embodiments of the present invention and are not intended to limit the scope of the embodiments of the present invention. That is, the equivalent changes and modifications made by the scope of the patent application of the present invention are covered by the scope of the invention.

Conventional knowledge

1. . . N-type semiconductor layer

2. . . Luminous layer

3. . . P-type semiconductor layer

4. . . Reflective layer

5. . . The buffer layer

6. . . Bonding layer

7. . .矽 substrate

8. . . P-type electrode

9. . . N-type electrode

this invention

D. . . distance

10. . . Light-emitting diode structure

11. . . N-type semiconductor layer

111. . . Irregular surface

12. . . Luminous layer

13. . . P-type semiconductor layer

14. . . Reflective layer

15. . . The buffer layer

16. . . Bonding layer

17. . .矽 substrate

18. . . P-type electrode

20. . . Nitride interlayer

30. . . N-type metal electrode layer

FIG. 1 is a structural diagram of a conventional light emitting diode.

Fig. 2A is a view showing a first embodiment of the present invention.

Figure 2B is a partial enlarged view of Figure 2A of the present invention.

Figure 3A is a diagram showing a second embodiment of the present invention.

Figure 3B is a partial enlarged view of Figure 3A of the present invention.

10. . . Light-emitting diode structure

11. . . N-type semiconductor layer

111. . . Irregular surface

12. . . Luminous layer

13. . . P-type semiconductor layer

14. . . Reflective layer

15. . . The buffer layer

16. . . Bonding layer

17. . .矽 substrate

18. . . P-type electrode

20. . . Nitride interlayer

30. . . N-type metal electrode layer

Claims (11)

A light-emitting diode electrical contact structure is applied to a light-emitting diode structure comprising an N-type semiconductor layer stacked to form a sandwich structure, a light-emitting layer and a P-type semiconductor layer, comprising:
a nitride intermediate layer patterned on the N-type semiconductor layer; and an N-type metal electrode layer formed on the nitride intermediate layer. The light-emitting diode electrical contact structure of claim 1, wherein the nitride intermediate layer is selected from the group consisting of aluminum nitride, titanium nitride and chromium nitride. For example, in the light-emitting diode electrical contact structure of claim 2, wherein the composition ratio of nitrogen and aluminum of aluminum nitride is X:1-X, and X is between 0.05 and 0.15, nitrogen of titanium nitride The composition ratio of titanium is X:1-X, and X is between 0.05 and 0.15. The composition ratio of nitrogen and chromium of chromium nitride is X:1-X, and X is between 0.05 and 0.15. The light-emitting diode electrical contact structure of claim 2, wherein the nitride intermediate layer has a thickness of 10 nm to 500 nm. The light-emitting diode electrical contact structure of claim 1, wherein the N-type metal electrode layer is selected from the group consisting of aluminum, titanium, nickel, chromium, platinum, and gold. The light-emitting diode electrical contact structure of claim 5, wherein the thickness of the N-type metal electrode layer is greater than 1 micrometer. The light-emitting diode electrical contact structure of claim 5, wherein the N-type metal electrode layer has at least two materials interlaced. The light-emitting diode electrical contact structure of claim 1, wherein the N-type semiconductor layer has an irregular surface, and the nitride intermediate layer and the N-type metal electrode layer are formed on the irregular surface. The illuminating diode electrical contact structure of claim 8, wherein the irregular surface is continuous zigzag. The illuminating diode electrical contact structure of claim 9, wherein the irregular surface has a distance greater than 500 nm. The light-emitting diode electrical contact structure of claim 1, wherein the N-type semiconductor layer has an irregular surface in a region not having the nitride intermediate layer.