KR100576317B1 - GaN-based LED and manufacturing method of the same utilizing the technique of saphire etching - Google Patents

Abstract

The present invention can reduce the size of the device, increase the thickness of the polished base substrate for separating the device, easy light extraction, uniform cleavage surface, can reduce the time and cost of manufacturing production As the nitride-based semiconductor light emitting diode and a manufacturing method thereof,

A sapphire base substrate, a buffer layer formed on the sapphire base substrate, a first conductive contact layer formed on the buffer layer, a first electrode connected to the first conductive contact layer, and formed on the first conductive contact layer A first cladding layer, a light emitting layer formed on the first conductive cladding layer, a second cladding layer formed on the light emitting layer, a second conductive contact layer formed on the second cladding layer, and the second conductive contacting layer In the nitride-based semiconductor light-emitting diode comprising a second electrode formed thereon, after chamfering the sapphire base substrate, and further comprising a reflecting film on the surface where the thin film of the sapphire base substrate is not formed The reflective film is made of any one of Ti, Rd, Pt, Ta, Ni, Cr, Au, or an alloy of these metals. The sapphire base substrate is chamfered to facilitate light extraction, characterized in that the chip structure is in the form of a triangle.

Sapphire base substrate, conductive contact layer, cladding layer, light extraction, light emitting diode, cleavage line

Description

Nitride-based semiconductor light emitting diodes and a method of manufacturing the same {GaN-based LED and manufacturing method of the same utilizing the technique of saphire etching}

1 is a planar structural diagram of a conventional nitride based semiconductor light emitting diode.

2 is a cross-sectional structure diagram of a conventional nitride semiconductor light emitting diode.

3 is a cross-sectional structure diagram of a nitride based semiconductor light emitting diode according to a first embodiment of the present invention.

4 is a cross-sectional structure diagram of a nitride based semiconductor light emitting diode according to a second embodiment of the present invention.

5 is a cross-sectional structure diagram of a nitride based semiconductor light emitting diode according to a third embodiment of the present invention.

6 is a cross-sectional view illustrating a case where a nitride semiconductor light emitting diode according to a fourth exemplary embodiment of the present invention is mounted in the form of a flip chip.

7 is a graph showing the etching rate of the sapphire base substrate for the ICP / RIE dry etching.

8 is a graph showing the etching rate of the sapphire base substrate for the solution of sulfuric acid and phosphoric acid.

9 is a view showing the surface of the sapphire base substrate etched with a solution of sulfuric acid and phosphoric acid mixed.

FIG. 10 is a cross-sectional view of the case where the sapphire base substrate is etched for a pattern having various line widths by a solution of sulfuric acid and phosphoric acid.

11 is a graph showing an etching depth for a pattern.

FIG. 12 shows an example in which a scribing line or a cleavage line of a sapphire base substrate is formed to separate devices by a wet etching method.

Explanation of symbols on the main parts of the drawings

11 buffer layer 12 contact layer

13 first cladding layer 14 light emitting layer

15: second clad layer 16: contact layer

17: second ohmic electrode 18: first electrode

19: second electrode 20: sapphire base substrate

21: reflective film 22: silver paste

23: first lead frame 24: second lead frame

The present invention relates to the field of optical devices, more specifically, to reduce the size of the device, to increase the thickness of the base substrate wrapped to separate the device, easy to extract light, uniform cleavage surface, BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nitride-based semiconductor light emitting diode and a method for manufacturing the same, which can reduce the time and cost of production.

A nitride semiconductor light emitting diode is one of light emitting devices that convert an applied current into light when a forward current flows for a predetermined time or more. The nitride semiconductor light emitting diode is formed by using a nitride semiconductor material to have a pin junction structure, and includes a nitride semiconductor material GaN, The emission wavelength is determined according to the type of GaAs, GaP, InP, InAs, InSb, or the like.

Nitride-based semiconductor light emitting diodes in the visible region, which are mainly used as light emitting devices for display devices, mainly use nitride-based semiconductor materials such as GaN, GaAs, and GaP, which have a light emission wavelength that can be recognized by humans. Blue nitride-based semiconductor light emitting diodes, which are mainly used as blue light emitting devices, have been expanded in the display device due to the advantages of realizing full color, and the demand will explode when considering the application as a light source. It is expected.

Generally, compound semiconductor light emitting diodes are grown on a conductive base substrate of GaAs, GaP, InP, InAs series, so it is not difficult to make a vertical electrode type light emitting diode having a p-n junction structure.

In the case of a nitride semiconductor light emitting diode, sapphire (Al ₂ O ₃ ) having a lattice constant and crystal structure similar to that of a nitride semiconductor is used as a base substrate in order to reduce crystal defects during epitaxial growth. When described with reference to as follows.

1 is a planar structural diagram of a conventional nitride based semiconductor light emitting diode, and FIG. 2 is a cross sectional structural view of a conventional nitride based semiconductor light emitting diode.

As can be seen in FIGS. 1 and 2, a conventional nitride based semiconductor light emitting diode uses sapphire as the base substrate 20.

In addition, the first electrode 18 and the second electrode 19 are present in parallel on one plane, and the light generated in the light emitting layer is emitted from the transparent second ohmic electrode 17 to the outside. Such a light emitting device is called a two-wire-bonding-type and is distinguished from a vertical electrode light emitting device in which one electrode is perpendicular to the other electrode. The two-wire bonding type light emitting diode structure is mainly used in nitride-based semiconductor light emitting diodes grown on the sapphire base substrate 20 as an insulator.

However, in the conventional nitride-based semiconductor light emitting diode, since the sapphire base substrate is an insulator, both the first electrode and the second electrode have to be formed on the growth surface of the epi layer, so that the wire bonding pad area must be secured. There is a problem with limitations.

In addition, conventional nitride-based semiconductor light emitting diodes have a rigid sapphire base substrate, so that the thickness of the wrapped base substrate for separating elements is about 75 to 100 μm, and is cleaved using a diamond pen or a laser. There is a problem of forming a line.

In addition, the conventional nitride-based semiconductor light emitting diode is difficult to process the sapphire base substrate in the form of easy light extraction because it is difficult to process.

In addition, conventional nitride-based semiconductor light emitting diodes are formed using a diamond pen or a laser light source to form a cleaving line and to break the device, because of the size of the diamond pen and the size of the laser beam. There is a problem that must secure a 40 ~ 50um, and when the cleavage of the cleavage surface is not uniform causing problems in appearance.

Accordingly, the conventional nitride-based semiconductor light emitting diodes require a lot of time and cost in the production and production, which hinders the improvement of the chip yield per wafer, resulting in a decrease in price competitiveness.

An object of the present invention is to solve such a conventional problem, it is possible to reduce the size of the device, to increase the thickness of the wrapped base substrate to separate the device, easy to extract light, uniform cleavage surface In addition, to provide a nitride-based semiconductor light emitting diode and a method for manufacturing the same, which can reduce the time and cost of production.

As a means for achieving the above object, the configuration of the apparatus of the present invention includes a sapphire base substrate, a buffer layer formed on the sapphire base substrate, a first conductive contact layer formed on the buffer layer, and the first conductive contact layer. A first electrode connected to the first electrode, a first cladding layer formed on the first conductive contact layer, a light emitting layer formed on the first conductive cladding layer, a second cladding layer formed on the light emitting layer, and the second cladding A nitride-based semiconductor light emitting diode comprising a second conductive contact layer formed on a layer and a second electrode formed on the second conductive contact layer, wherein the sapphire base substrate is chamfered and then the sapphire described above. It further comprises a reflective film on the surface where the thin film of the base substrate is not formed, the reflective film is Ti, Rd, Pt, Ta, Ni, It is made of one of Cr, Au, or an alloy of these metals, and the sapphire base substrate is chamfered to facilitate light extraction, characterized in that the chip structure is triangular.

As a means for achieving the above object, the configuration of the method of the present invention comprises the steps of: forming a first electrode and a second electrode on a nitride based semiconductor grown on a sapphire base substrate, lapping and polishing the sapphire base substrate, Forming a hard mask on the surface of the first electrode and the sapphire base substrate, and partially exposing the surface of the sapphire base substrate by photo etching the hard mask on the sapphire base substrate; Etching the exposed portion of the surface of the sapphire base substrate to form a chamfer and cleavage line, forming a chamfer or cleavage line of the sapphire base substrate, and then allowing the reflective film to surround the sapphire substrate so that the reflective film is not peeled off; It comprises a step of separating the device, in the lapping and mirror polishing step described above It is characterized by polishing the sapphire substrate using at least one of polishing, wet etching, and dry etching.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings in order to describe in detail enough to enable those skilled in the art to easily carry out the present invention. . Other objects, features, and operational advantages, including the object, operation, and effect of the present invention will become more apparent from the description of the preferred embodiment.

For reference, the embodiments disclosed herein are only presented by selecting the most preferred embodiment in order to help those skilled in the art from the various possible examples, the technical spirit of the present invention is not necessarily limited or limited only by this embodiment Rather, various changes, additions, and changes are possible within the scope without departing from the spirit of the present invention, as well as other equivalent embodiments.

3 is a cross-sectional structure diagram of a nitride based semiconductor light emitting diode according to a first embodiment of the present invention.

In the nitride-based light emitting diode fabricated using the prior art, it is difficult to process the sapphire base substrate, so that the sapphire base substrate is not chamfered, but the nitride-based semiconductor light emitting diode according to the first embodiment of the present invention can be seen in FIG. As shown, the sapphire base substrate 20 has a triangular shape with chamfers, and this structure makes light extraction easier by reducing the critical angle of the light.

4 is a cross-sectional structure diagram of a nitride based semiconductor light emitting diode according to a second embodiment of the present invention.

The structure of the nitride based semiconductor light emitting diode according to the second embodiment of the present invention is similar to that of the first embodiment, but the characteristic as shown in FIG. 4 is the chamfered surface of the sapphire base substrate 20. The reflective film 21 is deposited on the whole. The reflective film 21 directs the light directed toward the sapphire base substrate 20 to increase the light extraction efficiency. When the reflective film 21 is deposited by aluminum (Al), the light extraction efficiency increases by about 50%.

In addition, when the reflective film 21 covers the entire sapphire base substrate 20 as described above, the light extraction efficiency can be improved by preventing light from leaking to the side, and the reflective film 21 and the sapphire base substrate 20 The adhesive force between them and the adhesive is weak, so that the phenomenon of peeling off the metal film can be avoided.

5 is a cross-sectional structure diagram of a nitride based semiconductor light emitting diode according to a third embodiment of the present invention.

In the nitride based light emitting diode according to the third exemplary embodiment of the present invention, as shown in FIG. 5, chips are bonded to the first lead frame 23 and the second lead frame 24. The conductive silver paste 22 is used to attach the chip to the first lead frame 23, and the wire 25 is used to connect the second electrode 19 of the chip to the second lead frame 24. Made of structure.

The reflective film 21 deposited on the sapphire base substrate 20 is adhered to the conductive silver paste 22, but the reflective film 21 is formed to surround the sapphire base substrate 20. Since the lamp having such a package form does not react with the silver paste 22 because the light generated in the light emitting layer 14 does not cause aging of the silver paste 22 due to light, device reliability is improved, particularly in the ultraviolet region. It is effective in light emitting diodes.

FIG. 6 is a cross-sectional view illustrating a case where a nitride semiconductor light emitting diode according to a fourth exemplary embodiment of the present invention is mounted in the form of a flip chip. As shown in FIG. 6, the nitride-based semiconductor light emitting diode according to the fourth embodiment of the present invention allows light to be emitted from the sapphire base substrate 20 to the outside, and the first electrode 18 and the second electrode ( 19 is mounted on the lead frames 23 and 24.

In addition, by forming a protrusion on the sapphire base substrate 20 by using a wet etching technology has a structure to induce diffuse reflection of light to increase the light extraction efficiency. This structure is not only a blue nitride-based light emitting diode having a wavelength of 470 nm but also an In _x (Ga _y Al _1-y ) N (0 <x <1, 0 <y <1) series grown on a sapphire base substrate. Applicable to all nitride semiconductor light emitting diodes.

A method of manufacturing the nitride-based semiconductor light emitting diode according to the first, second, third, and fourth embodiments having the structure as described above is as follows.

First, the buffer layer 11 and the n-type first conductive contact layer are formed on the sapphire base substrate 20 by using metal organic chemical vapor deposition (MOCVD), liquid phase epitaxial method (LPE), molecular beam epitaxial method (MBE), or the like. (12), an epitaxial substrate on which the first cladding layer 13, the light emitting layer 14, the second cladding layer 15, and the p-type second conductive contact layer 16 are sequentially stacked is prepared.

The first conductive contact layer 12, the light emitting layer 14, and the second conductive contact layer 16 are formed of In _x (Al _y Ga _1-y ) N of a nitride semiconductor. Here, the composition ratios of x and y have values of 0 <x <1 and 0 <y <1. In particular, the light-emitting layer (14) is In _x (Al _y Ga _1-y) N in the barrier layer and the In _x (Al _y Ga _1-y) can be a single quantum well structure or a multiple quantum well structure consisting of N well layer, and By controlling the components of In, Ga, and Al, a short wavelength light emitting diode having an AlN (˜6.2 eV) band gap can be freely manufactured from a long wavelength having an InN (˜1.8 eV) band gap. Therefore, it will be appreciated by those skilled in the art that the present invention can be applied to all nitride based semiconductor light emitting diodes manufactured on a sapphire base substrate, without being limited to blue nitride based semiconductor light emitting diodes having a light emission wavelength of 460 nm. I think there will be.

Next, the ohmic layer or the transparent second ohmic electrode 17 is formed on the p-type second conductive contact layer 16, and the second electrode 19 is formed on the second ohmic electrode 17 described above. . The second ohmic electrode 17 and the second electrode 19 are formed using at least one of electron beam (e-beam) deposition, thermal evaporation, thermal evaporation, and sputtering.

The second ohmic electrode 17 may deposit a metal including at least one of NiO, NiAu, Ti, Ni, Au, Pd, Rh, Pt, Al, Cr, and Ta in a thin film form, or include one or more of these groups. When the alloy is deposited and heat treated at 200C to 700C in an atmosphere containing oxygen or nitrogen, good ohmic characteristics can be obtained. In this case, the second electrode may be formed as a transparent electrode or may have a mesh structure. Here, the first and second electrodes 17, 18, and 19 are formed using any one or more of electron beam (E-Beam) deposition, thermal evaporation, sputtering, and the like. The ohmic contact lowers the contact resistance between the metal electrode and the semiconductor layer.

After depositing the metal of any one of Ti / Ni / Au and Pd / Au on the second electrode 19, a temperature between 300 ° C. and 700 ° C. in a furnace containing nitrogen or oxygen is preferable. Preferably, heat treatment is performed at a temperature of about 500 to 600 ° C. to form a transparent ohmic contact with the second electrode 19 to lower the contact resistance with the semiconductor layer.

Subsequently, mesa etching is performed on the first conductive contact layer 12 to expose the first conductive contact layer 12, and then a first electrode 18 is deposited thereon. After the deposition of the first electrode 18, a heat treatment is performed at a temperature of 300 ° C to 700 ° C, preferably 500 to 600 ° C, in a furnace in a nitrogen or oxygen atmosphere to contact the semiconductor layer. Lower the resistance

The first electrode 18 deposits a single layer or multiple layers using alloys such as Ti, Al, Cr, Cr / Ni / Au, Ti / Al, Al, TiAl / Ti / Au, Ti / Ni / Au, Ta, and the like. By heat treatment at 200C to 700C in an atmosphere containing oxygen or nitrogen, good ohmic characteristics can be obtained.

Next, the sapphire base substrate 20 is cut by ICP (Inductive coupled plasma) / RIE (Reactive Ion Etching) dry etching and mechanical lapping, and the wrapped surface is mirror polished to make it smooth. At this time, the thickness of the sapphire base substrate 20 may be as thin as possible. However, if the thickness is too thin, the sapphire base substrate 20 may be wheely and difficult to be handled in the process. The reason for mixing mechanical polishing and wet etching in the step of polishing the sapphire base substrate 20 is to save time and cost. That is, while mechanical polishing has a high polishing speed, it is difficult to mirror the sapphire base substrate 20, and wet etching is slow and easy to make mirror surfaces.

Thereafter, by using the etching characteristics of the sapphire base substrate 20, the chamfer or cleave line 26 for device separation may be simultaneously performed. When the sapphire base substrate 20 is etched, the semiconductor surface and the electrode may be removed. In order to use as a hard mask while protecting, a protective film such as spin on glass, SiN, or SiO is deposited by about 1 μm. That is, after mirror polishing, a hard mask such as liquid glass, SiN, SiO, or the like is deposited as a protective film on the surface of the epitaxial film and the surface of the sapphire base substrate 20 by attaching a temporary substrate. At this time, it is preferable to form the protective film on the epitaxial film surface before polishing the sapphire substrate in order to prevent contamination of the epi surface.

Subsequently, the hard mask formed on the surface of the sapphire base substrate 20 is etched with Reactive Ion Etching (RIE) or Buffer Oxide Echant (BOE) to chamfer, scribe, or cleavage lines, and the sapphire base substrate 20 To expose a portion of the. At this time, the etching of the protective film is performed using RIE or BOE solution.

In the step of etching the exposed portion of the sapphire base substrate 20, one or more dry etching techniques such as CMP (Chemical Mechanical Polishing), ICP / RIE, Reactive Ion Etching (RIE), etc. may be used in combination, or wet. Etching techniques can also be used.

In the case of using the dry etching method, ICP / RIE or RIE is used for dry etching. In order to quickly etch the sapphire base substrate 20, it is desirable to increase the output of ICP and RIE as much as possible, but it may damage the nitride semiconductor epilayer. Be careful because you can.

When using the wet etching method, hydrochloric acid (HCl), nitric acid (HNO ₃ ), potassium hydroxide (KOH), sodium hydroxide (NaOH), sulfuric acid (H ₂ SO ₄ ), phosphoric acid (H ₃ PO ₄ ), and aloe The sapphire base substrate 20 may be etched by immersing in a mixed solution by any one of the values (4H ₃ PO ₄ + 4CH ₃ COOH + HNO ₃ + H ₂ O) or a combination thereof.

As described above, the sapphire base substrate 20 is a dry etching method using ICP / RIE or RIE, or hydrochloric acid (HCl), nitric acid (HNO ₃ ), potassium hydroxide (KOH), sodium hydroxide (NaOH), sulfuric acid (H _{In a} wet etching method using a mixed solution of any one or a combination of ₂ SO ₄ ), phosphoric acid (H ₃ PO ₄ ), aluene (4H ₃ PO ₄ + 4CH ₃ COOH + HNO ₃ + H ₂ O) Etching to a certain depth to form a chamfering line or scribing line (26).

Protective layers such as glass (gass), SiN, SiO, etc. used as hard masks in the above etching process are hydrochloric acid (HCl), nitric acid (HNO ₃ ), potassium hydroxide (KOH), sodium hydroxide (NaOH), sulfuric acid (H ₂ SO ₄ ), Hardly etched in mixed solutions such as phosphoric acid (H ₃ PO ₄ ) and allues (4H ₃ PO ₄ + 4CH ₃ COOH + HNO ₃ + H ₂ O), but also high etching in dry etching such as ICP / RIE. It is durable and its use range is large.

7 is a graph showing the etching rate of the sapphire base substrate for the ICP / RIE dry etching. As can be seen in Figure 7, the etching rate of the sapphire base substrate 20 is increased by increasing the ICP and RIE output (direct current bias voltage), the etching rate is 0.5um / min under a specific etching conditions It takes about 2 minutes to form 1um scribing line 27 and cleavage line 28 to the extent.

8 is a graph showing the etching rate of the sapphire base substrate for the solution of sulfuric acid and phosphoric acid. As can be seen in Figure 8, the etching rate of sapphire is more than 1um / min at a specific temperature, considering the production cost, productivity, process stabilization, process ease, etc., the method proposed by the present invention is advantageous than the conventional method You can see that.

9 is a view showing a surface etched sapphire base substrate with a mixture of sulfuric acid and phosphoric acid. As can be seen in Figure 9, the etched surface is clean and the etched surface is inclined at a constant angle. The sapphire base substrate 20 was etched at 22.4um for 20 minutes, resulting in an etching rate of 1.1um / min. This etching rate is comparable to the dry etching rate, and considering the mass production of chips, there is no problem at all. Wet etching is not limited by the productivity of the equipment. There is an advantage.

FIG. 10 is a cross-sectional view of the case where a sapphire base substrate is etched for a pattern having various line widths by a solution of sulfuric acid (H 2 SO 4) and phosphoric acid (H 3 PO 4). As can be seen in Figure 10, the etched depth of the sapphire base substrate 20 depends on the pattern width opened, it can be seen that the wider the line width is wider. Patterns with a line width of 57um are etched to a depth of 24um and the aspect ratio is 0.4, whereas patterns with a line width of 10um are only etched at a depth of 1.5um, so the aspect ratio is only 0.1. In other words, in wet etching, the thinner base substrate 20 is oriented in wet etching, and the etching depth depends on the patterned line width and the etching stops at a certain depth. In particular, not only the etch stops at a certain depth, but also no longer progresses laterally. Most commonly used sapphire base substrate 20 is a C-plane in the (0001) direction and when wet etching, as shown in Figure 9, the angle of the etching surface forms an inclined surface of about 54 degrees or 25 degrees. This phenomenon is due to the difference in etching speed between the (0001) plane and the etched facet plane of the R, M, and A-planes.

Based on the above results, the etching depth is determined by the open line width, and by adjusting the open line width, the etching depth can be adjusted freely. When the open line width is narrowed, the etching depth can be adjusted to a depth of 1um or less. It means that there is. The depth of the scribing line 26 or cleavage line 27 is sufficient 1um line width and depth, but the chamfering depth of the sapphire base substrate 20 to increase the extraction efficiency may be preferably 5 ~ 100um.

By utilizing such wet etching characteristics, since the etching is stopped at a predetermined depth, the chamfering and scribing lines 26 are formed, and thus the device can be easily manufactured without an additional process. In particular, since a specific etching surface is formed according to the direction of the sapphire base substrate 20 and the etching speed is different depending on the direction, when the nitride semiconductor is grown on the specific sapphire surface, the via hole is formed on the sapphire base substrate 20 by the wet etching technique. The vertical electrode type light emitting diode can be manufactured by forming a via hole to form the first electrode 18. In addition, wet etching the sapphire base substrate 20 on the (0001) plane can form a V-grooved shape line width, and thus it is expected that a device of a new nitride semiconductor structure such as a quantum thin line can be made. By growing a nitride-based semiconductor thin film it is possible to grow a high quality semiconductor thin film with less lattice defects and improved light extraction efficiency.

The wet etching of the sapphire base substrate 20 proceeds in the following manner.

The etching rate of the sapphire base substrate 20 by the etching solution using the test sapphire substrate may be measured and immersed in the etching solution for a time to etch the sapphire substrate having a thickness corresponding to 120% of the depth to be etched.

On the other hand, since the etching rate depends on the temperature of the solution, it is preferable to maintain the temperature of the etching solution at 60 ° C. or higher, preferably 280 to 350 ° C. to shorten the process time.

The heating for maintaining the temperature of the etching solution above 60 ℃ may employ a direct heating method to put the solution on the heater, or to directly contact the heater with the solution and indirect heating method using light absorption.

In addition, in order to increase the temperature of the etching solution to a temperature higher than the boiling point of the solution, the pressure may be raised above atmospheric pressure.

In order to form the scribing line 26 and the cleavage line 27 on the sapphire base substrate 20, dry etching techniques such as CMP, ICP / RIE, and RIE may be used.

FIG. 12 shows an example in which chamfered lines or scribing lines 26 and 27 of a sapphire base substrate are formed to separate devices by a wet etching method. In the case of forming a chamfer line, it is not necessary to form separate scribing lines 26 and 27. As can be seen in FIG. 12, the scribing line 27 or cleavage lines 26 and 27 may be formed using a wet etching method at a place where the device is to be separated or cleaved. In this step, the chamfer of the sapphire base substrate 20 and the scribing lines or cleavage lines 26 and 27 may be simultaneously performed. At this time, if the opening width of the passivation layer used as an etching mask is very narrow at the boundary between chips, the etching is automatically stopped at a certain depth during wet etching, so the etching should be made in consideration of the thickness and chamfering depth of the sapphire base substrate 20. . This is to ensure that the device is not separated at this stage. The depth of the scribing line or cleavage lines 26 and 27 is preferably about 1 to 3 μm, but when the chamfer of the sapphire base substrate 20 is used as the scribing line or cleavage lines 26 and 27, it is preferably 20 μm. May be deeper than 0.1-100um. In the conventional nitride-based semiconductor light emitting device manufacturing method, the chip spacing 26, 27 for separating the device is scribed to 40 ~ 50um, in the present invention, the chip spacing 26, 27 is reduced to within 10um This can increase the number of chips produced in one wafer.

In the semiconductor light emitting diode of the present invention, the reflective film 21 may be formed on the sapphire base substrate 20 to increase the light extraction efficiency. The reflective film 21 forms a chamfering line or scribing lines 26 and 27 and then etches SiN or SiO used as a hard mask to the BOE to provide excellent light reflectivity and form an ohmic contact. Deposition of any one of Ti, Al, Rd, Pt, Ta, Ni, Cr, Au or an alloy of these metals, or Ti / Al, Ti / Al / Au, Rh / Au, Rh / Au / Pt / It is formed by depositing any one of Au, Pd / Au, Ti / Al / Pt / Au, or an alloy of these metals, and then lifting it off. The device may then be cleaved to separate the device.

The method proposed in the present invention can be easily separated by forming a scribing line in the form of a triangle at a place where the device is to be separated by a dry or wet etching method, and by forming a sapphire base substrate into a triangle shape. The light extraction efficiency can be increased by lowering the light critical angle.

In addition, in the present invention, after forming a scribing line for device separation on the sapphire base substrate by using a wet etching technique, if the reflective film is deposited on the sapphire base substrate, not only the phenomenon that the reflective film is peeled off, but also light extraction The efficiency can be increased, the process is easy, and the process cost is low, so mass production is possible.

In addition, in the present invention, the productivity is greatly improved since the lapping, mirror polishing, and cleavage line formation for device isolation use any one or more of a mechanical polishing method and a dry or wet etching method, in particular, conventional scribing for device separation. By replacing the process with one or more of wet etching and dry etching techniques, device isolation is possible using only photo-photolithography techniques and etching techniques, which enables standardized processes and facilitates mass production.

As described in the above embodiment, the present invention can reduce the size of the device, can increase the thickness of the wrapped base substrate for separating the device, easy light extraction, uniform cleavage surface, manufacturing production It has the effect, which can reduce the time and cost.

Claims (34)

delete delete delete A sapphire base substrate, a buffer layer formed on the sapphire base substrate, a first conductive contact layer formed on the buffer layer, a first electrode connected to the first conductive contact layer, and formed on the first conductive contact layer A first cladding layer, a light emitting layer formed on the first conductive cladding layer, a second cladding layer formed on the light emitting layer, a second conductive contact layer formed on the second cladding layer, and the second conductive contacting layer In a nitride-based semiconductor light emitting diode comprising a second electrode formed thereon, After chamfering the sapphire base substrate, the sapphire base substrate further comprises a reflective film on the surface where the thin film is not formed, The reflective film is made of any one of Ti, Rd, Pt, Ta, Ni, Cr, Au, or an alloy of these metals, The sapphire base substrate is a nitride-based semiconductor light emitting diode, characterized in that the chip structure is chamfered to facilitate light extraction. The nitride-based semiconductor light emitting diode of claim 4, wherein the sapphire base substrate has a concave-convex shape. The nitride-based semiconductor light emitting diode of claim 4, wherein the sapphire base substrate has a thickness of 40um to 500um. The method of claim 4, wherein the buffer layer, the first conductive contact layer, the first cladding layer, the light emitting layer, the second cladding layer, the second conductive contact layer is In _x (Ga _y Al _1-y ) N (composition ratio x, y is A nitride based semiconductor light emitting diode comprising 0 <x <1, 0 <y <1). The nitride-based semiconductor light emitting diode of claim 4, wherein the first electrode is formed of any one of Ti / Ni / Au and Al metal structures. The nitride-based semiconductor light emitting diode of claim 4, wherein the second electrode is formed of any one of Ti / Ni / Au and Pd. delete delete Forming a first electrode and a second electrode on the nitride semiconductor grown on the sapphire base substrate, Wrapping and mirror-polishing the sapphire base substrate; Forming a hard mask on the surface of the first electrode and the surface of the sapphire base substrate; Photo-etching a hard mask on the sapphire base substrate to partially expose the surface of the sapphire substrate; Etching the exposed portions of the surface of the sapphire base substrate to form chamfers and cleavage lines; Forming a chamfer or cleavage line of the sapphire base substrate and then allowing the reflective film to surround the sapphire substrate so that the reflective film does not peel off; It comprises a step of separating the device, In the lapping and mirror polishing step, the sapphire substrate is polished using at least one of mechanical polishing, wet etching, and dry etching. The method of claim 12, wherein in the wet etching method, hydrochloric acid (HCl), nitric acid (HNO ₃ ), potassium hydroxide (KOH), sodium hydroxide (NaOH), sulfuric acid (H ₂ SO ₄ ), phosphoric acid (H ₃ PO ₄ ) And an etchant using a mixed solution of any one or a combination of aluenes (4H ₃ PO ₄ + 4CH ₃ COOH + HNO ₃ + H ₂ O). The method of claim 13, wherein the etching solution is used in a state of being heated to a temperature of 60 ° C. or higher. The method of claim 14, wherein the heating is performed by a direct heating method using a heater. The method of claim 14, wherein the heating is performed by indirect heating using light absorption. The method of manufacturing a nitride-based semiconductor light emitting diode according to claim 14, wherein the pressure is raised above atmospheric pressure to increase the temperature to a high temperature during the heating. The method of claim 12, wherein the dry etching method uses any one of ICP / RIE and RIE. The method of claim 12, wherein in the device isolation step, a cleavage line for device isolation is formed using at least one of a wet etching method and a dry etching method. 20. The method of claim 19, wherein the wet etching method includes hydrochloric acid (HCl), nitric acid (HNO ₃ ), potassium hydroxide (KOH), sodium hydroxide (NaOH), sulfuric acid (H ₂ SO ₄ ), phosphoric acid (H ₃ PO ₄ ). And an etchant using a mixed solution of one or a combination of aluenes (4H ₃ PO ₄ + 4CH ₃ COOH + HNO ₃ + H ₂ O). 20. The method of claim 19, wherein the dry etching method uses any one of ICP / RIE and RIE. The method of claim 19, wherein in the dry etching method, at least one of BCL ₃ , Cl ₂ , HBr, and Ar is used as an etching gas. The method of claim 12, wherein the chamfering and cleaving lines are etched to form a triangle (V-groove). The method of claim 12, wherein the chamfering and cleaving lines are etched to form trenches. The method of manufacturing a nitride-based semiconductor light emitting diode according to claim 12, wherein said cleavage line formation and chamfering for light extraction are simultaneously performed. The method of claim 12, wherein the forming of the chamfer and cleavage line comprises using at least one of a wet and a dry etching method. 27. The method of claim 26, wherein the wet etching method comprises hydrochloric acid (HCl), nitric acid (HNO ₃ ), potassium hydroxide (KOH), sodium hydroxide (NaOH), sulfuric acid (H ₂ SO ₄ ), phosphoric acid (H ₃ PO ₄ ). And an etchant using a mixed solution of one or a combination of aluenes (4H ₃ PO ₄ + 4CH ₃ COOH + HNO ₃ + H ₂ O). 27. The method of claim 26, wherein the dry etching method uses any one of ICP / RIE and RIE. The method of claim 26, wherein in the dry etching method, at least one of BCL ₃ , Cl ₂ , HBr, and Ar is used as an etching gas. The method of manufacturing a nitride-based semiconductor light emitting diode according to claim 12, wherein said protective film uses at least one of epoxy, glass, SiN, and SiO. The method of claim 12, wherein in the lapping and mirror polishing steps, the thickness of the sapphire substrate is in the range of 40 to 400 um. The method of claim 12, wherein in the chamfering step, the chamfering depth thickness of the sapphire substrate is 0.1 to 100um. The method of claim 12, wherein in the cleavage line forming step, the sapphire base substrate is etched in a range of 0.01 to 100 μm. 13. The method of claim 12, wherein in the polishing step, the surface of the sapphire substrate is mirror polished to have a roughness of 10 μm or less.

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