JPH05102524A - Semiconductor element - Google Patents

Abstract

PURPOSE:To prevent the erosion and the exfoliation of an electrode at the time of etching for eliminating the strain of a dicing surface, by covering the electrode with a layer of material which is not eroded by etching liquid. CONSTITUTION:A P-type electrode 23 is formed on the lower surface of an element main body constituted of P-type compound semiconductor 21 and N-type compound semiconductor 22. An N-side electrode 28 of four-layered structure is formed on the upper surface of the element main body. Said four-layered structure is formed by laminating the following in order; an ohmic contact layer 24, a first high melting point metal layer 25, a second high melting point metal layer 26, and an Au layer 27 of electrode metal. The Au layer 27 covers the side surfaces of the three layers under the layer 27, and is in contact with the upper surface of the element main body. That is, the whole part of the N-side electrode 28 is covered with the Au layer 27. Thereby the electrode can be prevented from being eroded at the time of wet etching for eliminating the strain of the dicing surface after dicing, and the exfoliation of the electrode can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor element such as a light emitting diode used as a light emitting portion or a display element of various sensors.

[0002]

2. Description of the Related Art A conventional light emitting diode is shown in FIG. In this figure, 1 is a P-type compound semiconductor layer, and 2 is an N-type compound semiconductor layer laminated thereon, and these two layers form the element body. The P-side electrode 3 is provided on the lower surface of the element body, while N is provided on the upper surface of the element body.
Side electrodes 4 are provided. The N-side electrode 4 includes an ohmic contact layer 5 of AuGe or the like, a first refractory metal layer 6 of Ti or the like, a second refractory metal layer 7 of Pt or the like for preventing mutual diffusion, or Au from the element body side. The electrode metal layer 8 has a four-layer structure.

By the way, the above-mentioned light emitting diodes are integrally manufactured by using a compound semiconductor wafer, and then the wafer is diced (divided) to be divided into a large number of individual light emitting diodes. At that time, distortion occurs on the dicing surface (side surface 9 in FIG. 2). In order to remove the distortion, the dicing surface is wet-etched after dicing.

[0004]

However, in the conventional light emitting diode as described above, at the time of the etching, as shown in FIG.
Corrosion 10 is generated in the first refractory metal layer 6 made of i or the like, and there is a problem that the electrode is peeled off. As a result, defects such as poor appearance, poor wire bonding, and poor characteristics occur in the assembly process.

The present invention has been made in view of the above points, and an object of the present invention is to provide a semiconductor element capable of preventing electrode erosion and preventing electrode peeling during etching for strain removal of a dicing surface.

[0006]

According to the present invention, in a semiconductor element having an electrode on a semiconductor layer, the electrode is covered with a material layer which is not eroded by an etching solution.

[0007]

When the electrode is covered with the material layer, the electrode is prevented from being eroded by the etching solution at the time of etching for removing strain on the dicing surface, and the electrode is prevented from peeling off.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a light emitting diode as an embodiment of the present invention. In this figure, 21 is P
The type compound semiconductor layer, 22 is an N-type compound semiconductor layer laminated on the type compound semiconductor layer, and the element body is constituted by these two layers. The P-side electrode 23 is provided on the lower surface of the element body. On the other hand, on the upper surface of the element body, for example, AuG
An ohmic contact layer 24 made of e, a first refractory metal layer 25 made of Ti or the like, a second refractory metal layer 26 made of Pt or the like for preventing mutual diffusion, and an Au layer 27 of an electrode metal are sequentially laminated. An N-side electrode 28 having a four-layer structure is provided, and the Au layer 27 further covers the side surfaces of the underlying three layers (the first and second refractory metal layers 25 and 26 and the ohmic contact layer 24). It is in contact with the upper surface of the element body. That is, in this light emitting diode, the N-side electrode 28
Will be covered with the Au layer 27 that is not eroded by the etching solution. Therefore, even after performing dicing (division) after manufacturing a large number of integrated semiconductors on a compound semiconductor wafer and performing wet etching to remove the strain on the dicing surface, the first refractory metal layer 25 made of Ti or the like still has the etching liquid. The Au layer 27 prevents the erosion by the electrode, and the electrode does not come off.

As the layer that covers the N-side electrode 28 and prevents erosion, a material other than Au can be used. Further, it is needless to say that the present invention can be applied to similar elements other than the above light emitting diode.

[0010]

As described above in detail, according to the present invention, the electrode is covered with the material layer which is not eroded by the etching solution, so that the wet etching for removing the strain of the dicing surface after dicing is performed. The electrodes can be prevented from being eroded and the electrodes can be prevented from peeling off. Therefore,
It is possible to prevent a decrease in yield due to defects such as a defective appearance, a defective wire bond, and a defective characteristic during assembly.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a semiconductor device of the present invention.

FIG. 2 is a sectional view showing a conventional light emitting diode.

FIG. 3 is a cross-sectional view showing a conventional problem.

[Explanation of symbols]

 21 P-type compound semiconductor layer 22 N-type compound semiconductor layer 27 Au layer 28 N-side electrode

Claims (1)

[Claims] 1. A semiconductor device having an electrode on a semiconductor layer, wherein the electrode is covered with a material layer which is not corroded by an etching solution.