KR100437181B1 - Method for manufacturing semiconductor laser diode - Google Patents

Abstract

The present invention relates to a method for fabricating a semiconductor jizer diode, comprising the steps of: patterning a photoresist layer except for a region where a p-electrode and an n-electrode are to be formed; Depositing a metal in a region where the p-electrode and the n-electrode are to be formed to form a p-electrode and an n-electrode; Removing the photoresist layer to form separate p- and n-electrodes, respectively; A scribing process is performed between the separated p-electrode and the n-electrode to fabricate a semiconductor laser diode to separate each semiconductor laser diode.

Therefore, the present invention can manufacture a semiconductor laser diode having a high quality mirror by scribing between the separated p-electrode and n-electrode, thereby improving the electrical characteristics of the device, increasing the yield, and improving the reliability. Occurs.

Description

Method for manufacturing semiconductor laser diode

The present invention relates to a method for manufacturing a semiconductor laser diode, and more particularly, to form a separate p-electrode and n-electrodes during the process of manufacturing a plurality of semiconductor laser diodes, the separated p-electrode and n- The present invention relates to a method for manufacturing a semiconductor laser diode capable of forming a high quality mirror by scribing between electrodes.

In general, an active device having a very small metal terminal is formed in a semiconductor process, and a large pad is formed as an external connection terminal for providing an electrical signal to the active device, and a metal layer exists between the pad and the pad. Interconnect active devices.

In general, group III-V nitride semiconductors such as gallium nitride are widely used in high temperature and high power electronic devices as well as light emitting devices and light receiving devices that emit light ranging from ultraviolet rays to visible light.

In order to manufacture a semiconductor laser diode using such a nitride semiconductor, a sapphire (0001) substrate or a substrate in which gallium nitride was grown on a sapphire substrate was used.

Using a substrate in which gallium nitride is grown on a sapphire substrate, a plurality of semiconductor laser diode structures are fabricated from gallium nitride, and the substrate is scribed to separate the semiconductor laser diode structures, and the sapphire is cut. The direction in which the gallium nitride is cut and the direction in which the gallium nitride is cut are shifted by 30 degrees.

For this reason, it is difficult to obtain the cut mirror surface of a favorable semiconductor laser diode, and a mirror loss arises and the performance of a semiconductor laser diode is reduced.

1A to 1E are diagrams illustrating manufacturing processes of a conventional semiconductor laser diode. First, an undoped GaN layer 20, an n-GaN layer 21, and an n-AlGaN cladding layer 22 are formed on an upper portion of a sapphire substrate 10. ), the n-GaN waveguide layer 23, the active layer 24, the p-GaN waveguide layer 25, the p-AlGaN cladding layer 26 and the p-GaN layer 27 are sequentially stacked. Figure 1a)

Then, Mesa is etched from the p-GaN layer 27 to a part of the n-GaN layer 21 (FIG. 1B).

Subsequently, a portion of the p-GaN layer 27 'is etched to form a ridge 27'a, and the mesa etched region, the etched p-GaN layer 27'b and the A dielectric film 28 is formed on all structural surfaces of the sapphire substrate including the ridges 27'a (FIG. 1C).

After removing the dielectric film of the upper surface of the ridge 27'a and a portion of the mesa-etched n-GaN layer 27 ', the transparent electrode 29 is disposed on the exposed upper surface of the ridge 27'a. To form (FIG. 1D).

After that, the p-electrode 30 is deposited to surround the transparent electrode 29, and at the same time, the n-electrode 31 is deposited on the n-GaN layer exposed by the removal of the dielectric film. Is completed. (FIG. 1E).

2 is a plan view of a state in which a semiconductor laser diode according to the related art is manufactured, which is a plan view in which two semiconductor laser diode structures are manufactured, and tens to hundreds of semiconductor laser diode structures are manufactured on a sapphire substrate.

Here, the deposition of the p-electrode 30 and the n-electrode 31 in FIG. 1E described above is performed by the first semiconductor laser diode structure 50 and the second semiconductor laser diode structure 51, as shown in FIG. 2. To be deposited successively.

Then, by scribing with a-a 'line, the first and second semiconductor laser diode structures 50 and 51 are separated, respectively.

At this time, the p-electrode 30 and the n-electrode 31 which are successively deposited are separated from the deposited interface during the scribing process and are torn off.

Therefore, in the conventional manufacturing process of the semiconductor laser diode, the p-electrode and the n-electrode are separated, and thus a good mirror cannot be obtained, and the electrical characteristics are deteriorated.

Accordingly, the present invention has been made to solve the above problems, and during the manufacturing process of a plurality of semiconductor laser diodes, p-electrodes and n-electrodes which are separated, respectively, are formed to separate the p-electrodes and n. It is an object of the present invention to provide a method for manufacturing a semiconductor laser diode capable of forming a high quality mirror by scribing between electrodes.

A preferred aspect for achieving the above object of the present invention is a method of manufacturing semiconductor laser diodes,

patterning the photoresist layer except for the region where the p-electrode and the n-electrode are to be formed;

Depositing a metal in a region where the p-electrode and the n-electrode are to be formed to form a p-electrode and an n-electrode;

Removing the photoresist layer to form separate p- and n-electrodes, respectively;

There is provided a method of manufacturing a semiconductor laser diode, comprising: separating each semiconductor laser diode by performing a scribing process between the separated p-electrode and n-electrode.

Another preferred aspect for achieving the above object of the present invention is a method of manufacturing semiconductor laser diodes,

Forming a transparent electrode on the ridge upper surface;

Patterning a photoresist layer on an upper portion of the transparent electrode and an area where an n-electrode is to be formed;

A third step of forming a dielectric film on all exposed surfaces after the second step;

A fourth step of exposing the region where the photoresist layer was present by peeling the photoresist layer together with the dielectric layer on the photoresist layer by an organic cleaning process;

After the fourth step, a p-electrode is formed in a region where the p-electrode is to be formed while covering the upper portion of the transparent electrode by using a mask, and a region where the n-electrode exposed to the dielectric film is formed by peeling the photoresist layer. Forming an n-electrode at the second stage to form separate n-electrodes and p-electrodes;

And a sixth step of separating the semiconductor laser diodes by performing a scribing process between the separated p-electrodes and the n-electrodes.

1A to 1E are manufacturing process diagrams of a conventional semiconductor laser diode.

2 is a plan view of a state in which a semiconductor laser diode according to the related art is manufactured.

3A and 3B are manufacturing process diagrams of a semiconductor laser diode according to a first embodiment of the present invention.

4A and 4B are plan views of FIGS. 3A and 3B, respectively.

5A to 5D are manufacturing process diagrams of a semiconductor laser diode according to a second embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

28 dielectric film 29 transparent electrode

30 p-electrode 31 n-electrode

40: photoresist layer

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

3A and 3B are manufacturing process diagrams of a semiconductor laser diode according to a first embodiment of the present invention, and FIGS. 4A and 4B are plan views of FIGS. 3A and 3B, respectively.

In the first and second embodiments of the present invention, the undoped GaN layer 20 and the n-GaN layer (top) of the sapphire substrate 10 are the same as those of the conventional FIGS. 1A to 1C described above. 21), n-AlGaN cladding layer 22, n-GaN waveguide layer 23, active layer 24, p-GaN waveguide layer 25, p-AlGaN cladding layer 26 and p-GaN layer Stacking (27) sequentially; Then mesa etch from p-GaN layer 27 to a portion of n-GaN layer 21; A portion of the p-GaN layer 27 'is etched to form a ridge 27'a, and the mesa etched region, the etched p-GaN layer 27'b and the ridge ( Forming a dielectric film (28) on all structural surfaces of the sapphire substrate including 27'a); After removing the dielectric film of the upper surface of the ridge 27'a and a portion of the mesa-etched n-GaN layer 27 ', the transparent electrode 29 is disposed on the exposed upper surface of the ridge 27'a. To form.

Subsequently, a region 45, in which a p-electrode and an n-electrode including an exposed region are removed by removing a dielectric layer of an upper surface of the ridge 27'a and a portion of the mesa-etched n-GaN layer 27 '. Except for 46, a photoresist layer 40 is formed over the dielectric film 28 (FIGS. 3A and 4A).

Of course, in the future, the photoresist layer 40 is also formed on the dielectric layer 28 between the scribed first and second semiconductor laser diodes 50 and 51.

Next, a metal layer is deposited on the regions 45 and 46 where the p-electrode and the n-electrode exposed by the photoresist layer 40 are to be formed, thereby separating the p-electrodes 30a and 30b and n separated from each other. Electrodes 31a and 31b are formed, and the photoresist layer 40 is removed (FIGS. 3B and 4B).

The semiconductor laser diode according to the first embodiment of the present invention manufactured as described above has a b-b 'in which the p-electrodes 30a and 30b and the n-electrodes 31a and 31b are separated, respectively, as shown in plan view 4b. When scribing with lines, the scribing force is not applied to each of the p-electrodes 30a and 30b and the n-electrodes 31a and 31b, so that a high quality mirror can be obtained without affecting.

5A to 5D are manufacturing process diagrams of a semiconductor laser diode according to a second embodiment of the present invention.

In the second embodiment of the present invention, the same process as in the first embodiment is performed, and then a portion of the p-GaN layer 27 'is etched to form a ridge 27'a, and the ridge ( 27'a) A transparent electrode 29 is formed on the upper surface. (FIG. 5A).

Next, a photoresist layer 40 is formed on the upper portion of the transparent electrode 29 and a part of the mesa-etched n-GaN layer 27 'where the n-electrode is to be formed (FIG. 5B).

A dielectric layer 28 is formed on all structural surfaces of the sapphire substrate including the mesa etched region, the etched p-GaN layer 27'b and the photoresist layer 40 (FIG. 5C).

Subsequently, an organic washing process is performed on the dielectric layer 28 with acetone, and the photoresist layer 40 and the dielectric layer thereon are separated to expose the region where the photoresist layer 40 exists.

Then, the p-electrodes separated from each other while covering the upper portion of the transparent electrode 29 by using a mask are formed to correspond to each of the semiconductor laser diodes, and the n-GaN layer 27 'with the photoresist layer peeled off. The n-electrodes separated from each other in the mesa-etched region are formed to correspond to each of the semiconductor laser diodes (FIG. 5D).

When the scribing process is performed using a dielectric film in which the p-electrode and the n-electrode are separated, the first and second semiconductor laser diodes 50 and 51 are separated, so that the electrodes are not affected by the present invention. It is possible to manufacture a semiconductor laser diode having

As described above, the semiconductor laser diodes of the first and second embodiments of the present invention are edge emitting semiconductor laser diodes in which laser light is emitted from the mirror of the side surface, and characteristics of the device are formed by forming a high quality mirror. There is an advantage to improve.

As described in detail above, the present invention forms a separate p-electrode and n-electrodes during the process of manufacturing a plurality of semiconductor laser diodes, and scribes between the separated p-electrode and the n-electrode to obtain high quality. It is possible to form a mirror, thereby improving the electrical properties of the device, there is an effect that can improve the yield and reliability.

Although the invention has been described in detail only with respect to specific examples, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

Claims (2)

A method of manufacturing semiconductor laser diodes, patterning the photoresist layer except for the region where the p-electrode and the n-electrode are to be formed; Depositing a metal in a region where the p-electrode and the n-electrode are to be formed to form a p-electrode and an n-electrode; Removing the photoresist layer to form separate p- and n-electrodes, respectively; And separating each semiconductor laser diode by performing a scribing process between the separated p- and n-electrodes. A method of manufacturing semiconductor laser diodes, Forming a transparent electrode on the ridge upper surface; Patterning a photoresist layer on an upper portion of the transparent electrode and an area where an n-electrode is to be formed; A third step of forming a dielectric film on all exposed surfaces after the second step; A fourth step of exposing the region where the photoresist layer was present by peeling the photoresist layer together with the dielectric layer on the photoresist layer by an organic cleaning process; After the fourth step, a p-electrode is formed in a region where the p-electrode is to be formed while covering the upper portion of the transparent electrode by using a mask, and a region where the n-electrode exposed to the dielectric film is formed by peeling the photoresist layer. Forming an n-electrode at the second stage to form separate n-electrodes and p-electrodes; And a sixth step of separating each semiconductor laser diode by performing a scribing process between the separated p-electrode and n-electrode.