KR100672553B1 - Nitride light emitting device and method for fabricating the same - Google Patents

Abstract

The present invention relates to a nitride light emitting device having a band of blue and green wavelengths, the first semiconductor layer, the active layer and the second semiconductor layer being sequentially formed on a substrate, and implanting ions at predetermined depths into regions where cleaved surfaces are to be formed. After the insulating film was formed, electrodes were formed on the second semiconductor layer and the substrate, and the devices were separated based on the respective insulating films to form cleaved surfaces having insulating films on both sides of the device, and then the high reflective film ( HR), and an antireflective film AR is formed on the insulating film on the other side to produce it. The present invention manufactured as described above can ensure the reliability of the device by suppressing the generation of joule heat due to the current by forming an insulating layer in the device cleavage, and the light generated inside the device is not absorbed from the cleavage surface to prevent light loss and cleavage surface It has the effect of reducing damage.

LED / LD, semiconductor light emitting device, insulating film

Description

Nitride light emitting device and method for manufacturing the same

1 is a structural cross-sectional view of a conventional nitride light emitting device and the energy band gap according to each layer

2a to 2d is a process perspective view showing a manufacturing process of the nitride light emitting device according to the prior art

3a to 3e is a process perspective view showing a manufacturing process of the nitride light emitting device according to the present invention

Explanation of symbols for main parts of the drawings

31 semiconductor substrate 32 n-type semiconductor layer

33: active layer 34: p-type semiconductor layer

35 n-type electrode 36 p-type electrode

37 insulating film 38 antireflective coating film

39: high reflection coating film 40: unit device

The present invention relates to a nitride light emitting device having a band of blue and green wavelengths.

In general, optical devices and electronic devices using III-V nitride semiconductors have already been developed, and light emitting diodes / laser diodes (LEDs / LDs) in the ultraviolet or visible light range have been applied to various fields. Usage is getting wider.

Nitride semiconductors have a bandgap energy of about 1.95 to 6.0 eV depending on their composition, and thus have been attracting attention as materials of semiconductor light emitting devices such as light emitting diodes (LEDs) and laser diodes (LDs). Recently, as a result of using such a nitride semiconductor material, high-brightness blue LEDs and green LEDs are actually used. The LED has a double heterostructure having a p-n junction, and a conventional LED structure has a double heterostructure in which an active layer made of InGaN is basically formed between n and p type coating layers made of AlGaN.

LD has a structure similar to that of LED, but generally has a separation limit structure in which light and carrier are limited. As shown in FIG. 1, the InGaN active layer is between p, n type GaN optical guide layers, and a p, n type AlGaN cladding layer exists around it.

2A to 2D are process perspective views illustrating a manufacturing process of a nitride light emitting device according to the prior art.

First, as shown in FIG. 2A, after compound semiconductors are grown, electrodes are formed to complete the device.                         

Subsequently, as shown in FIG. 2B, the cleaved surface is formed by separating the elements, and then, as shown in FIG. 2C, the antireflective film AR and the high reflective film HR are coated on both cleaved surfaces.

And finally, as shown in Figure 2d, the device coated with a non-reflective film and a high reflection film on the cleaved surface, respectively, with a chip to produce a unit device.

However, the above-mentioned conventional nitride light emitting device and its manufacturing method have the following problems.

First, when a current is injected into the device electrode to operate the light emitting device, not only Joule heat caused by the high current is generated, but also the light generated inside the device is absorbed and more heat is generated due to the light absorption. As a result, damage to the cleaved surface, such as melting of the cleaved surface of the device, causes the device output to fall or become inoperable.

Second, current flows through the cleaved portion due to the current injection into the device, resulting in optical loss due to absorption of light from the cleaved surface, thereby degrading the reliability of the device.

Accordingly, an object of the present invention is to provide a nitride light emitting device having high reliability by preventing damage to the cleaved portion and reducing light loss at the cleaved portion.

In the method of manufacturing a nitride light emitting device according to the present invention for achieving the above object, a first semiconductor layer, an active layer, and a second semiconductor layer are sequentially formed on a substrate, and ions are predetermined in regions where wall openings are to be formed. Forming an insulating film by implanting at a depth; forming electrodes on the second semiconductor layer and the substrate, and separating devices based on each insulating film to form a cleaved surface having insulating films on both sides of the device; Forming a high reflection film on the insulating film and forming an antireflection film on the insulating film on the other side.

Here, the width to which ions are implanted is 20% or less of the device length, and the implantation depth of ions is between the substrate of the device and the active layer. The implanted ion is any one of B, H, He, N _{2 and} O ₂ , the ion energy is about 100 to 900 KeV, and the dose is 10 ¹⁰ to 10 ¹⁹ atoms / cm 2. On the other hand, after the formation of the insulating film by implanting ions, the heat treatment may be performed. At this time, the heat treatment temperature is 400 to 1200 ° C, the time is 10 minutes to 4 hours, and the atmosphere is any one of nitrogen, ammonia, hydrogen, and atmosphere. Set to vacuum.

The present invention manufactured as described above can ensure the reliability of the device by suppressing the generation of joule heat due to the current by forming an insulating layer in the device cleavage, and the light generated inside the device is not absorbed from the cleavage surface to prevent light loss and cleavage surface Damage can be reduced.

Hereinafter, the nitride light emitting device manufacturing method according to the present invention will be described in detail with reference to the accompanying drawings.

In general, in order to operate the light emitting device, a current is injected into the device electrode, and light is generated when holes and electrons flow through the p and n layers, respectively, and electron holes recombine in the active layer. The light reaches the cleavage plane along the light guide layer, which reflects light from the cleavage plane, amplifies inside the device, and emits light through the cleavage when the threshold is reached. In order to realize a high output light emitting device, more current needs to be injected, and more light is irradiated onto the cleaved surface. At this time, current flows on the cleaved surface, so Joule heat is generated due to high current, and it absorbs light generated inside the device due to instability on the cleaved surface. When heat is absorbed, more heat is generated. As a result, damage to the cleavage surface occurs such that the cleavage surface of the device melts and the light can no longer be emitted. In order to prevent these phenomena, it is necessary to prevent Joule heat generation due to current on the device cleavage surface and to prevent heat generation due to absorption of light on the device cleavage surface.

Therefore, the present invention undergoes the following manufacturing process.

3A to 3E are structural perspective views illustrating a manufacturing process of the nitride light emitting device according to the present invention.

First, as shown in FIG. 3A, the n-type semiconductor layer 32, the active layer 33, and the p-type semiconductor layer 34 are sequentially formed on the substrate 31, and as shown in FIG. 3B. Ion implantation is performed along the line where the cleaved surface is to be formed at a portion to be cleaved later, and an insulating film is formed by heat treatment. Here, the width of the region into which ions are to be implanted may vary depending on the length of the device, but it is better to be about 20% or less of the device length, and the implantation depth of ions is at least up to n-type semiconductor layer 32 and is maximized. What is necessary is just to up to the board | substrate 31 upper part. In addition, the implanted ions are implanted using B, H, He, N ₂ , O _2, etc., and using ion implanters. In this case, the ion implantation energy at the time of ion implantation is different for each material, but in the embodiment of the present invention, the ion implantation energy is about 100 to 900 KeV, and the dose is adjusted to 10 ¹⁰ to 10 ¹⁹ atoms / cm 2. Ion implant. On the other hand, heat treatment may be performed to alleviate damage to the nitride film caused by ion implantation. At this time, the heat treatment temperature is about 400 to 1200 ° C., the heat treatment time is 10 minutes to 4 hours, and the nitrogen atmosphere, the ammonia atmosphere, It is carried out in hydrogen atmosphere, vacuum state and the like. Subsequently, electrodes 35 and 36 are formed above the p-type semiconductor layer 34 and the substrate, respectively.

As shown in FIG. 3C, the devices are separated based on the insulating film to form cleaved surfaces having insulating films 37 on both sides of the device, and as shown in FIG. 3D, the antireflective films are formed on both of the cleaved surfaces. 38 and the high reflection film 39 are coated.

Finally, as shown in FIG. 3E, the device having the antireflection film 38 and the high reflection film 39 coated on the cleaved surface is separated into chips to manufacture the unit device 40.

The semiconductor device according to the present invention as described above has the following effects.

First, by forming the insulating layer in the cleavage of the device, it is possible to suppress the generation of joule heat due to the current to ensure the reliability of the device.                     

Second, by forming an insulating layer on the device cleavage surface, the effective bandgap at the cleavage portion is increased, so that light generated inside the device is not absorbed at the cleavage surface, thereby preventing the cleavage surface from melting due to light absorption.

Third, due to the formation of an insulating layer in the device cleavage, no current flows through the cleavage surface, thereby reducing light loss due to absorption of light in the cleavage surface, thereby realizing a high power light emitting device.

Claims (7)

In the nitride light emitting device manufacturing method having a cleaved surface on both sides, A first semiconductor layer, an active layer, and a second semiconductor layer are sequentially formed on the substrate; A first step of forming an insulating film in the isolation region of the first semiconductor layer, the active layer, and the second semiconductor layer; A second step of forming electrodes on the second semiconductor layer and the substrate, and separating the devices based on the respective insulating films to form cleaved surfaces having insulating films on both sides of the devices; And, And a third step of forming a high reflection film (HR) on the insulating film on one side of the device and forming an anti-reflection film (AR) on the insulating film on the other side. The method of claim 1, wherein the insulating film of the first step is formed, And implanting ions into the device isolation region, wherein the implantation depth is between the substrate and the active layer of the device. The method of claim 1, wherein in the first step: The implantation ion is any one of B, H, He, N _{2 and} O ₂ , the ion energy is 100 to 900 KeV, and the dose is 10 ¹⁰ to 10 ¹⁹ atoms / cm 2. The method of claim 1, wherein in the first step, And heat treatment after the insulating film is formed. The method of claim 4, wherein the temperature of the heat treatment is 400 to 1200 ℃, the time is 10 minutes to 4 hours, the atmosphere is nitrogen, ammonia, hydrogen, the atmosphere of any one of the nitride light emitting device manufacturing, characterized in that Way. In a nitride light emitting device having a cleaved surface on both sides, Insulating films formed on both of the cleaved surfaces; A reflective film formed on the insulating film on one side; And, And a non-reflective film formed over the insulating film on the other side. The nitride light emitting device according to claim 6, wherein the both insulating films are formed only on a part of the cleaved surface.

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