JP5957984B2 - Manufacturing method of semiconductor light emitting device - Google Patents

Description

The present invention relates to a method for manufacturing a semiconductor light emitting device formed by splitting a GaAs substrate.

  In recent years, semiconductor light emitting devices represented by laser diodes and light emitting diodes are required to have high output, high efficiency, and high reliability. In order to satisfy these requirements, it is necessary to build quality in the development and design stages of the device. In particular, a high-power element has a large load due to current and light, so that crystal defects grow quickly. Therefore, in order to ensure reliability, a technique for reducing crystal defects more than before and a technique for invalidating crystal defects are indispensable.

  The manufacturing process of the semiconductor light emitting device includes a step of dividing the substrate into device units. In this step, a dividing groove is put in the substrate (scribing), and a blade is applied along the groove to apply a load to break the substrate (break). At this time, since the crystal is mechanically broken, various cracks are inevitably generated on the fracture surface, and crystal defects are generated based on these cracks. In order to prevent the crystal defect from being transmitted to the element region, it has been proposed to form a groove filled with an oxide film or the like in the vicinity of the dicing line (see, for example, Patent Document 1).

JP-A-4-251960

  The crystal defects in the divided parts proliferate in response to the current applied to the element and the energy of light emitted from the element. Therefore, when the element is operated at a high output, the defect propagation rate increases, and the reliability of the element increases. There is a problem of significantly reducing the performance. Further, if a groove is formed in the vicinity of the dicing line, the chip size increases. In the case of GaAs, a high quality thermal oxide film cannot be formed due to the nature of the substance.

The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a semiconductor light emitting device capable of preventing a crystal defect generated when a GaAs substrate is broken from affecting a light emitting layer . A manufacturing method is obtained.

  The method of manufacturing a semiconductor light emitting device according to the present invention includes a step of forming a semiconductor multilayer structure having a light emitting layer on a GaAs substrate, a step of forming a groove in the semiconductor multilayer structure, and the light emission exposed in the groove. A step of selectively etching a part of the layer; and a step of selectively etching the part of the light emitting layer and then splitting the GaAs substrate along the groove.

  According to the present invention, crystal defects generated when a GaAs substrate is broken can be prevented from affecting the light emitting layer.

It is sectional drawing of the manufacturing process of the semiconductor light-emitting device based on Embodiment 1 of this invention. It is sectional drawing of the manufacturing process of the semiconductor light-emitting device based on Embodiment 2 of this invention. It is sectional drawing of the manufacturing process of the semiconductor light-emitting device based on Embodiment 2 of this invention. It is sectional drawing of the manufacturing process of the semiconductor light-emitting device based on Embodiment 2 of this invention. It is sectional drawing of the manufacturing process of the semiconductor light-emitting device based on Embodiment 3 of this invention. It is sectional drawing of the manufacturing process of the semiconductor light-emitting device based on Embodiment 4 of this invention. It is sectional drawing of the manufacturing process of the semiconductor light-emitting device based on Embodiment 5 of this invention.

  A semiconductor light emitting device and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings. The same or corresponding components are denoted by the same reference numerals, and repeated description may be omitted.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view of the manufacturing process of the semiconductor light emitting element according to Embodiment 1 of the present invention. First, a semiconductor laminated structure 5 in which an n-type cladding layer 2, a light emitting layer 3, and a p-type cladding layer 4 are laminated on an n-type GaAs substrate 1 is formed. Next, the groove 6 is formed in the semiconductor multilayer structure 5.

  Next, a part of the light emitting layer 3 exposed in the groove 6 is selectively etched using a liquid for etching only the material of the light emitting layer 3. For example, when the light emitting layer 3 is GaAs and the cladding layers 2 and 4 are AlGaInP, only GaAs of the light emitting layer 3 can be selectively etched by using a mixed solution of sulfuric acid, hydrogen peroxide solution and pure water.

  Next, an electrode 7 is formed on the semiconductor multilayer structure 5, and an electrode 8 is formed on the back surface of the n-type GaAs substrate 1. Thereafter, the n-type GaAs substrate 1 is split along the groove 6. In the device manufactured in this way, the n-type GaAs substrate 1 is divided by the divided portion 9, and a part of the light emitting layer 3 is recessed inward from the side surface of the semiconductor multilayer structure 5 in the divided portion 9.

  With the above configuration, even if the n-type GaAs substrate 1 is bent and cracked greatly and the dividing boundary 10 enters inside the groove 6, the dividing boundary 10 is applied to the light emitting layer 3 to prevent crystal defects from occurring. Can do. Therefore, it is possible to prevent crystal defects generated when the n-type GaAs substrate 1 is broken from affecting the light emitting layer 3. As a result, high output, high efficiency, and high reliability can be realized.

Embodiment 2. FIG.
2-4 is sectional drawing of the manufacturing process of the semiconductor light-emitting device based on Embodiment 2 of this invention. First, as shown in FIG. 2, a semiconductor multilayer structure 5 having a light emitting layer 3 is formed on an n-type GaAs substrate 1. Next, a window region 11 in which the band gap of the light emitting layer 3 is widened by diffusion of impurities such as zinc is formed. The window region 11 is formed deeper than the light emitting layer 3.

  Next, as shown in FIG. 3, a high resistance region 12 is formed in the semiconductor multilayer structure 5 by ion implantation of protons or the like. An electrode 7 is formed on the semiconductor multilayer structure 5, and an electrode 8 is formed on the back surface of the n-type GaAs substrate 1.

  Next, as shown in FIG. 4, the groove 6 is formed in the semiconductor multilayer structure 5 in or near the window region 11 and the high resistance region 12. Next, the n-type GaAs substrate 1 is divided along the groove 6. In the element manufactured in this way, the window region 11 and the high resistance region 12 are provided in the semiconductor multilayer structure 5 in the vicinity of the divided portion 9.

  With the above configuration, the light emitting layer 3 in the window region 11 does not absorb the light that oozes out from the peripheral light emitting layer 3. Further, no current flows in the vicinity of the divided portion 9 due to the high resistance region 12. Therefore, the energy of both light and current can be blocked in the vicinity of the divided portion 9.

  As a result, even if the n-type GaAs substrate 1 is bent and cracked, and even if the dividing boundary 10 enters inside the groove 6 and the crystal defect 13 is generated in the light emitting layer 3, energy of light and current is not applied. The growth of the defect 13 can be stopped or delayed. Therefore, it is possible to prevent the crystal defect 13 generated when the n-type GaAs substrate 1 is broken from affecting the light emitting layer 3. As a result, high output, high efficiency, and high reliability can be realized.

Embodiment 3 FIG.
FIG. 5 is a cross-sectional view of the manufacturing process of the semiconductor light emitting element according to Embodiment 3 of the present invention. First, a semiconductor multilayer structure 5 having a light emitting layer 3 is formed on an n-type GaAs substrate 1. Next, a window region 11 in which the band gap of the light emitting layer 3 is widened by impurity diffusion is formed.

  Next, an electrode 7 is formed on a part of the semiconductor multilayer structure 5, and an electrode 8 is formed on the back surface of the n-type GaAs substrate 1. Next, a groove 6 is formed in the semiconductor multilayer structure 5 in or near the window region 11. However, the electrode 7 should not be present in the vicinity of the groove 6. Next, the n-type GaAs substrate 1 is divided along the groove 6.

  In the element thus manufactured, the window region 11 is provided in the vicinity of the divided portion 9, and the electrode 7 provided on the semiconductor multilayer structure 5 does not exist in the vicinity of the divided portion 9. As described above, since the electrode 7 does not exist in the vicinity of the divided portion 9, no current flows in the vicinity of the divided portion 9. Therefore, the same effect as in the second embodiment can be obtained.

Embodiment 4 FIG.
FIG. 6 is a cross-sectional view of the manufacturing process of the semiconductor light emitting element according to Embodiment 4 of the present invention. The window region 11 and the high resistance region 12 are formed as in the second embodiment, and a part of the light emitting layer 3 exposed in the groove 6 is selectively etched as in the first embodiment. Thereby, the effect of both Embodiment 1 and Embodiment 2 can be acquired.

Embodiment 5 FIG.
FIG. 7 is a cross-sectional view of the manufacturing process of the semiconductor light emitting device according to the fifth embodiment of the present invention. The window region 11 is formed as in the third embodiment, the electrode 7 is not present in the vicinity of the divided portion 9, and a part of the light emitting layer 3 exposed in the groove 6 is selected as in the first embodiment. Etch. Thereby, the effect of both Embodiment 1 and Embodiment 3 can be acquired.

1 n-type GaAs substrate 3 light emitting layer 5 semiconductor laminated structure 6 groove 7 electrode 9 divided portion 11 window region 12 high resistance region

Claims (3)

Forming a semiconductor multilayer structure having a light emitting layer on a GaAs substrate;
Forming a groove in the semiconductor multilayer structure;
Selectively etching a part of the light emitting layer exposed in the groove;
And a step of selectively etching a part of the light emitting layer and then splitting the GaAs substrate along the groove. Forming a window region in which the band gap of the light emitting layer is widened by impurity diffusion;
A step of forming a high resistance region in the semiconductor multilayer structure by ion implantation,
The method for manufacturing a semiconductor light emitting element according to claim 1, wherein the groove is formed in or near the window region and the high resistance region. Forming a window region in which the band gap of the light emitting layer is widened by impurity diffusion;
Forming an electrode on a part of the semiconductor multilayer structure,
Forming the groove in or near the window region;
Producing how the semiconductor light-emitting device according to claim 1, wherein the electrode is so not present in the vicinity of the groove.

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