JP2003309289A - Nitride semiconductor light-emitting element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nitride semiconductor light-emitting element which can control an etching quantity and which has a large light output and high reliability, and to provide a method for manufacturing the same. <P>SOLUTION: The nitride semiconductor light-emitting element comprises: a second conductivity-type nitride semiconductor layer 6; a light emitting layer 5; and a first conductivity-type nitride semiconductor layer 4, sequentially formed on a holding metal plate 9; and an etching marker layer 3 containing In and formed on the first conductivity-type nitride semiconductor layer. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nitride-based semiconductor light-emitting device capable of emitting light in the blue region to the ultraviolet region and a method for manufacturing the same, and particularly to a nitride-based semiconductor device having a large optical output and high reliability, which makes it possible to control the etching amount. The present invention relates to a semiconductor light emitting device and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in order to provide an inexpensive nitride semiconductor light emitting device, various nitride semiconductor light emitting devices using Si (silicon) as a substrate have been used. FIG. 11 shows a schematic cross-sectional view of a conventional nitride-based semiconductor light emitting device using Si for the substrate.

The nitride semiconductor light emitting device shown in FIG.
At least the buffer layer 400, the lower clad layer 300, the light emitting layer 200, and the upper clad layer 100 are sequentially stacked on the substrate 500, and the p-type pad electrode 600 on the upper clad layer 100 and the n-type electrode 700 on the back surface of the Si substrate 500.
Are formed.

The conventional nitride-based semiconductor light emitting device described above has the following problems. That is, the light generated from the light emitting layer 200 is applied to the top surface, the side surface of the light emitting element and the Si substrate
The light emitted to the 00 side and emitted to the Si substrate 500 side enters the Si substrate 500. However, since the Si substrate 500 absorbs a large amount of light (light having a short wavelength here) from the light emitting layer 200, a large light output could not be expected in the conventional nitride-based semiconductor light emitting device.

Therefore, a method has been proposed in which a metal plate that reflects light and can be used as an electrode is used instead of the Si substrate. However, there is a problem that it is difficult to grow a nitride-based semiconductor layer on a metal plate. Further, in the method of bonding the metal plate and the nitride-based semiconductor layer using the conductive adhesive, there is a problem that the light emitting element deteriorates early because the heat dissipation of the conductive adhesive is not excellent. It was

Therefore, after a buffer layer and a nitride-based semiconductor layer are sequentially laminated on a Si substrate to form a metal plate on the nitride-based semiconductor layer, the Si substrate and the buffer layer are removed to expose the exposed nitride-based semiconductor. A method of providing electrodes on the layer is conceivable. Especially when the buffer layer is highly resistive or non-conductive, it is necessary to remove the buffer layer. But Si
Although the substrate can be selectively removed by the wet etching method, it was difficult to selectively remove the buffer layer.

That is, since the buffer layer is hardly etched by the wet etching method, the dry etching method is usually used. However, since this dry etching method does not show the selectivity like the wet etching method, the etching amount is Is difficult to control. Generally, the etching amount is controlled by the etching time, but it is still difficult to control the etching amount.

Therefore, if the etching amount of the buffer layer becomes too large, the nitride semiconductor layer is also etched, and the film thickness of this layer becomes thin, so that the current does not sufficiently spread in this layer and the light emitting element There has been a problem that the light emitting region is narrowed and a light emitting device having a large light output cannot be obtained. On the other hand, if the etching amount is too small, the buffer layer will remain on the nitride-based semiconductor layer, and if the buffer layer is highly resistive or non-conductive, it will be difficult to inject current into the light emitting device and the operating voltage will increase. There is a problem in that the reliability of the light emitting device is lowered due to the increase in the cost.

[0009]

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a nitride-based semiconductor light-emitting device that enables control of the etching amount and has a large light output, and a method for manufacturing the same. Also, the present invention provides a nitride-based semiconductor light emitting device having high reliability even when a highly resistive or non-conductive buffer layer is laminated on a substrate in the process of manufacturing the light emitting device, and a method for manufacturing the same. With the goal.

[0010]

To achieve the above object, the present invention provides a second conductivity type nitride-based semiconductor layer, a light emitting layer, and a first conductivity type nitride, which are sequentially formed above a holding metal plate. A nitride-based semiconductor light emitting device including an etching marker layer containing In formed on the first conductivity type nitride-based semiconductor layer.

Here, the nitride-based semiconductor light-emitting device in which the electrode is formed on the etching marker layer containing In or the first conductivity type nitride system exposed by partially removing the etching marker layer containing In. It is preferable that the nitride-based semiconductor light emitting device has an electrode formed on a semiconductor layer.

The material of the etching marker layer containing In is preferably InN, InGaN or InGaAlN.

It is preferable that the layer in contact with the In-containing etching marker layer in the first conductivity type nitride semiconductor layer contains Al.

The present invention also provides a buffer layer, I, on the substrate.
a step of sequentially forming an etching marker layer containing n, a first-conductivity-type nitride-based semiconductor layer, a light-emitting layer, a second-conductivity-type nitride-based semiconductor layer, and a holding metal plate, and at least a part of the substrate and the buffer layer. The present invention relates to a method for manufacturing a nitride-based semiconductor light-emitting device, which includes a step of performing etching until at least an In signal is detected during etching and removal.

In the above manufacturing method, it is preferable that the first conductivity type nitride semiconductor layer is exposed by continuing the etching even after the In signal is no longer detected.

The buffer layer is preferably highly resistive or non-conductive, and the material of the buffer layer is preferably AlN or AlGaN.

Further, the substrate is preferably made of Si.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

(Substrate) The material of the substrate used in the present invention is a conventionally known material such as Si or GaAs.
Alternatively, GaP or the like is used. Si is preferably used. When Si is used for the substrate, the crystallinity of the nitride-based semiconductor layer laminated on the buffer layer can be improved by disposing the buffer layer on the substrate. Further, since a large-area substrate can be obtained at low cost, a light emitting element can be manufactured on a large scale, so that the manufacturing cost of the light emitting element is reduced. Moreover, the substrate can be easily processed.

(Buffer Layer) The buffer layer used in the present invention is laminated on the substrate. The material of the buffer _{layer, In x Al y Ga 1-} xy N (0 ≦ x, 0 ≦ y, x + y
A conventionally known nitride-based semiconductor material represented by ≦ 1) can be used. AlN or AlGaN is preferably used. When AlN or AlGaN is used for the buffer layer, since the buffer layer does not contain In, it is possible to clearly distinguish the etching marker layer containing In from the end point detection device of the dry etching device. Therefore, the function of the etching marker layer containing In as the etching marker layer can be sufficiently exhibited.
Further, the buffer layer may be conductive, highly resistive or non-conductive, but when the buffer layer is highly resistive or non-conductive, the importance of the etching marker layer containing In becomes important. Increase.

(Etching Marker Layer Containing In) The etching marker layer containing In used in the present invention is laminated on the buffer layer. The material of the etching marker layer containing In is In _x Al _y Ga _{1-x- y} N (0 <
A conventionally known nitride-based semiconductor material represented by x, 0 ≦ y, x + y ≦ 1) can be used. Preferably InN,
It is preferably either InGaN or InAlGaN. Further, it is more preferable that the content of In is larger than that of the buffer layer and the first-conductivity-type nitride-based semiconductor layer. When the In content is high, the function as the etching marker layer can be more exerted.

Further, since it contains In, this layer tends to be a soft layer, which reduces damage to the light emitting layer during the etching. Further, mechanical damage to the light emitting layer during wire bonding to the pad electrode is reduced. Therefore, by disposing this layer, the layer functions as an absorption layer for damage to the light emitting layer, so that the reliability of the light emitting element can be improved.

The etching marker layer means a layer having a function of detecting an In signal by the end point detecting device of the etching device.

(First conductivity type nitride semiconductor layer) The first conductivity type nitride semiconductor layer used in the present invention is laminated on the etching marker layer containing In. As the material of the first conductivity type nitride semiconductor _{layer, In x Al y Ga 1-} xy N
A conventionally known nitride-based semiconductor material represented by (0 ≦ x, 0 ≦ y, x + y ≦ 1) can be used.

Here, the first conductivity type nitride semiconductor layer is 1
Not only the layer, but may be composed of two or more nitride semiconductor layers. In this case, it is preferable that the layer in contact with the In-containing etching marker layer contains Al. When the etching approaches the first-conductivity-type nitride-based semiconductor layer containing Al from the etching marker layer containing In, the etching rate sharply decreases, so that the end point of etching can be clearly determined, and the reproducibility is improved. The first conductivity type nitride-based semiconductor layer containing Al well can be exposed.

The layer also contains an n-type dopant or p
Either of the type dopants is doped.

(Light Emitting Layer) The light emitting layer used in the present invention is
It is laminated between the first conductivity type nitride semiconductor layer and the second conductivity type nitride semiconductor layer. The light emitting layer may be an MQW (multiple quantum well) light emitting layer or an SQW (single quantum well) light emitting layer.

(Second conductivity type nitride semiconductor layer) The second conductivity type nitride semiconductor layer used in the present invention is In
_{x Al y Ga 1- xy N (} 0 ≦ x, 0 ≦ y, x + y ≦ 1) known nitride-based semiconductor materials conventionally represented by may be employed.

Further, the second conductivity type nitride-based semiconductor layer is not limited to one layer, but may be composed of two or more nitride-based semiconductor layers.

This layer also contains an n-type dopant or p
One of the type dopants is doped, but a dopant of a type different from that of the first-conductivity-type nitride semiconductor layer is doped.

(Nitride Semiconductor Contact Layer) A nitride semiconductor contact layer can be laminated on the second conductivity type nitride semiconductor layer. The material used in the nitride-based semiconductor contact _{layer, In x Al y Ga 1-} xy N (0
A conventionally known nitride-based semiconductor material represented by ≦ x, 0 ≦ y, x + y ≦ 1) can be used.

This layer also contains an n-type dopant or p
One of the type dopants is doped, but a dopant of the same type as the second-conductivity-type nitride semiconductor layer is doped.

As a method of laminating each of the above-mentioned layers, a conventionally known method can be used, for example, VPE method (vapor phase epitaxy method), MOCVD method (metal organic chemical vapor deposition method), MBE method. (Molecular beam epitaxy method) or a combination of these methods can be used.

Further, conventionally known materials can be used for the above-mentioned n-type dopant, for example, Si (silicon), O (oxygen), Cl (chlorine), S (sulfur), C (carbon) or Ge. (Germanium) or the like can be used.

Also, conventionally known materials can be used for the above-mentioned p-type dopant, for example, Mg (magnesium), Zn (zinc), Cd (cadmium) or B.
e (beryllium) or the like may be used.

(Underlayer) An underlayer can be formed on the nitride-based semiconductor contact layer. As a method of forming the underlayer, a conventionally known method can be used, and for example, one or more of a vapor deposition method, a CVD method (chemical deposition method), and a sputtering method can be used.

(Holding Metal Plate) The holding metal plate used in the present invention is used as an electrode and is formed on the underlayer. As a material of the holding metal plate, a conventionally known metal can be used, but Ni (nickel) or Au is used.
It is preferable to use a metal whose main component is (gold). Both heat dissipation and conductivity are good, and a highly reliable light emitting element which is not deteriorated early can be manufactured.

As a method of forming the holding metal plate,
A conventionally known method can be used, and for example, one or more of vapor deposition method, CVD method, sputtering method, electrolytic plating, and electroless plating method can be used. The electrolytic plating method is preferred. When the electroplating method is used, a thick film holding metal plate can be easily produced in a short time, and the holding metal plate produced by the electroplating method has an adhesive force with the underlying layer. Since it is improved and peeling does not occur, the reliability of the light emitting element tends to be improved.

The thickness of the holding metal plate is preferably 10 μm or more and 2 mm or less. If the thickness of the holding metal plate is 10 μm or more, the light-emitting element can be easily handled even when the substrate is removed, and if it is thicker than 2 mm, it tends to be difficult to divide and cut the holding metal plate. . Further, the light emitting element tends to be too large.

(Etching) As a method of etching the substrate, a conventionally known method, for example, a wet etching method, a dry etching method or a combination thereof can be used. The wet etching method is preferable. In this case, the buffer layer functions as an etching stop layer, the manufacturing process is facilitated, and the manufacturing cost can be reduced. Further, when the substrate is made of Si, if a mixed solution of hydrofluoric acid, nitric acid and acetic acid is used as an etching solution, the substrate made of Si can be selectively etched.

As a method of etching the buffer layer, a dry etching method such as a reactive ion etching method or a plasma etching method is used. The reactive ion etching method is preferred. When the etching marker layer containing In is etched, since In is detected by the end point detection device, it can be easily determined that the etching reaches the etching marker layer containing In, The etching amount can be easily controlled.

Therefore, the etching amount becomes too large and the film thickness of the first-conductivity-type nitride-based semiconductor layer becomes thin, the current does not spread to the first-conductivity-type nitride-based semiconductor layer, and the light-emitting region of the light-emitting element is small. And the problem that the buffer layer remains because the etching amount becomes too small when the buffer layer has high resistance or is non-conductive, and the light emitting element does not emit light.

Further, the etching marker layer containing In can also be etched. Here, the etching method is preferably the same as that for the buffer layer.

Further, at the time of the above-mentioned etching, by simultaneously etching the dummy wafers laminated with the same material and film thickness as the wafer to be etched, it is possible to control the etching amount with higher accuracy.

As the dry etching device, a conventionally known device including an end point detecting device can be used. Here, as the detection method of the end point detection device, an emission spectroscopy analysis method, a reflected light analysis method, a gas analysis method, a laser interferometry method, an impedance measurement method, a pressure measurement method, or the like is used. The emission spectroscopy is preferred. When the emission spectroscopic analysis method is used, high sensitivity tends to be obtained directly from the system which is reacting by etching.

(Electrode) The electrode used in the present invention is In
Is formed on the etching marker layer including or on the first conductivity type nitride semiconductor layer.

(Pad Electrode) A pad electrode can be formed on the electrode. The material of the pad electrode is Au
(Gold) is preferably used. In addition, Au on the pad electrode
It is possible to bond a wire made of the like.

As a method of forming the electrodes and pad electrodes, a conventionally known method can be used. For example, any one or a plurality of vapor deposition method, CVD method and sputtering method can be used.

[0049]

EXAMPLES The present invention will be described in more detail with reference to examples.

Example 1 FIG. 1 is a schematic sectional view of a nitride semiconductor light emitting device of this example. The nitride-based semiconductor light-emitting device of this example has a base layer 8, a nitride-based semiconductor contact layer 7, a second conductivity type nitride-based semiconductor layer 6, and an MQW light-emitting layer 5 that are sequentially installed on a holding metal plate 9. The first conductivity type nitride semiconductor layer 4, the etching marker layer 3 containing In, the electrode 10, the pad electrode 11 and the Au wire 12.

The manufacturing process of the nitride semiconductor light emitting device of this embodiment will be described below with reference to FIGS.

First, the substrate 1 made of Si is set in the growth apparatus, and the buffer layer 2 made of AlN is formed on the substrate 1 to a thickness of 20 using the MOCVD growth method, as shown in FIG.
0 nm, an In-containing etching marker layer 3 of n-type In _0.2 Ga _0.8 N having a thickness of 100 nm, a first conductivity type nitride semiconductor layer 4 of n-type GaN having a thickness of 400 nm,
The MQW light emitting layer 5 has a thickness of 50 nm and p-type Al _0.2 Ga _0.8 N
A second conductivity type nitride-based semiconductor layer 6 having a thickness of 10 n
Nitride-based semiconductor contact layer 7 made of m, p-type GaN
To sequentially form a wafer having a thickness of 200 nm.

Next, the wafer is taken out from the growth apparatus and, as shown in FIG. 3, Pd is formed as a base layer 8 on the nitride-based semiconductor contact layer 7 with a thickness of 50 nm by A using an evaporation method.
u is formed to have a thickness of 100 nm, and a holding metal plate 9 is formed thereon.
Then, Ni is formed to a thickness of 80 μm by electrolytic plating.

Next, as shown in FIG. 4, the substrate 1 is removed by a wet etching method using a hydrofluoric acid-based etching solution to expose the buffer layer 2.

Next, as shown in FIG. 5, the buffer layer 2 is removed by a dry etching method using chlorine gas, here a reactive ion etching method, to expose the etching marker layer 3 containing In. Here, in order to completely expose the etching marker layer 3 containing In, the etching is continued for 20 seconds after the signal of In is detected by the end point detection device of the dry etching device. Dry etching is completed with the etching marker layer 3 containing In being completely exposed. The emission spectroscopic analysis method was used as the endpoint detection method.

Then, as shown in FIG. 6, Ti was formed into a substantially square shape having a side of 150 μm and a thickness of 5 nm as an electrode 10 on the etching marker layer 3 containing In serving as a light emitting surface by vapor deposition. Then, Al is formed to a thickness of 5 nm, and Au is formed thereon to a thickness of 0.5 μm as the pad electrode 11.

After that, the wafer is divided into substantially quadrangular shapes each side of which is 350 μm square, the holding metal plate 9 side is mounted on the bottom of the cup of the lead frame, and the Au wire 12 is bonded onto the pad electrode 11.

The nitride-based semiconductor light-emitting device of this example obtained as described above has In between the buffer layer 2 made of AlN and the first conductivity type nitride-based semiconductor layer 4 made of n-type GaN. By forming the etching marker layer 3 containing a, In can be clearly detected by the end point detection device, and thus the etching amount of the non-conductive buffer layer 2 can be easily controlled.

Therefore, in this embodiment, it is possible to obtain a highly reliable nitride-based semiconductor light emitting device having a large optical output.

(Embodiment 2) FIG. 7 is a schematic sectional view of a nitride semiconductor light emitting device of this embodiment. The nitride-based semiconductor light-emitting device of this embodiment includes a base layer 28, a nitride-based semiconductor contact layer 27, which are sequentially installed on a holding metal plate 29.
Second conductivity type nitride-based semiconductor layer 26, MQW light emitting layer 25,
The first-conductivity-type nitride-based semiconductor layer 24, the etching marker layer 23 containing In, the electrode 210, the pad electrode 211, and the Au wire 212.

Here, the present embodiment is characterized in that the etching marker layer 23 containing In is composed of InN containing no Ga, so that the function as an etching marker layer is further exerted.

The process of manufacturing the nitride semiconductor light emitting device of this embodiment will be described below. First, as shown in FIG.
A buffer layer 22 made of AlN having a thickness of 150 nm, an etching marker layer 23 containing In made of n-type InN having a thickness of 50 nm, and a first conductivity type nitride semiconductor layer 24 made of n-type GaN are formed on a substrate 21 made of n. Thickness 500nm,
The MQW light emitting layer 25 has a thickness of 40 nm and p-type Al _0.2 Ga _0.8.
The second conductivity type nitride-based semiconductor layer 26 made of N has a thickness of 5n.
Nitride-based semiconductor contact layer 2 composed of m and p-type GaN
A wafer is formed by sequentially stacking 7 in a thickness of 150 nm.

Next, Pd having a thickness of 30 nm is formed as a base layer 28 on the nitride-based semiconductor contact layer 27 by an evaporation method, and Au is made a thickness of 100 μm as a holding metal plate 29 by an electrolytic plating method. Form.

Next, the substrate 21 is removed with a hydrofluoric acid-based etching solution using a normal photo process, and the buffer layer 2 is removed.
Expose 2

Next, the buffer layer 22 is removed by a dry etching method using chlorine gas, here a reactive ion etching method, and an etching marker layer 23 containing In is removed.
Expose. Here, in order to completely expose the etching marker layer 23 containing In, the etching is continued for 20 seconds after the signal of In is detected by the end point detection device of the dry etching device. The etching is completed with the etching marker layer 23 containing In completely exposed.

Next, by using a vapor deposition method, In which becomes a light emitting surface is formed.
As an electrode 210 on the etching marker layer 23 including Ti, Ti is formed in a substantially square shape with 90 μm square on a side to a thickness of 5 nm.
Then, Au is formed thereon as a pad electrode 211 to a thickness of 0.5 μm.

After that, the wafer is divided into a substantially square shape having 350 μm square on a side, the holding metal plate 29 side is mounted on the bottom of the cup of the lead frame, and A is placed on the pad electrode 211.
Bond the u-wire 212.

The nitride-based semiconductor light-emitting device of this example obtained as described above has a buffer layer 22 made of AlN.
Conductivity type nitride-based semiconductor layer 24 composed of GaN and n-type GaN
By forming the etching marker layer 23 containing In, which is made of InN containing no Ga, between In and, the In can be clearly detected by the end point detection device. Buffer layer 2 that is conductive
The etching amount of 2 can be controlled.

Therefore, in this embodiment, it is possible to obtain a nitride-based semiconductor light emitting device having higher reliability than that of the first embodiment.

(Embodiment 3) FIG. 9 shows a schematic sectional view of a nitride-based semiconductor light emitting device of this embodiment. The nitride-based semiconductor light-emitting device according to the present embodiment includes an underlayer 38, a nitride-based semiconductor contact layer 37, a second conductivity type nitride-based semiconductor layer 36, an MQW light-emitting layer 35, which is provided on a holding metal plate 39. First conductivity type nitride semiconductor layer 34, first conductivity type nitride semiconductor layer 341 containing Al, etching marker layer 33 containing In, buffer layer 32, electrode 310, pad electrode 31.
1 and Au wire 312.

Here, in this embodiment, the buffer layer 3
A part of the etching marker layer 33 containing 2 and In is etched, and the electrode 310 is formed on the first conductivity type nitride semiconductor layer 341 containing Al exposed by the etching.

The process of manufacturing the nitride semiconductor light emitting device of this embodiment will be described below. First, a buffer layer 32 made of AlN having a thickness of 200 is formed on a substrate (not shown) made of Si.
nm, an etching marker layer 33 containing In composed of n-type In _0.3 Ga _0.7 N with a thickness of 100 nm and n-type Al _0.1 G
a _0.9 N of the first conductivity type nitride semiconductor layer 341 containing Al, the thickness of the first conductivity type nitride semiconductor layer 34 of n type GaN of 400 nm, and the thickness of the MQW light emitting layer 35. 40 nm, a second conductivity type nitride semiconductor layer 36 made of p-type Al _0.1 Ga _0.9 N having a thickness of 5 nm and a nitride semiconductor contact layer 37 made of p-type GaN having a thickness of 150 nm are sequentially laminated to form a wafer. .

Next, using a vapor deposition method, Pd as a base layer 38 having a thickness of 30 n is formed on the nitride-based semiconductor contact layer 37.
m, and a metal plate 3 for holding the metal by electroplating
As Ni, Ni is formed to a thickness of 80 μm.

Next, using a normal photo process, the substrate (not shown) is removed over the entire surface using a hydrofluoric acid-based etching solution to expose the buffer layer 32.

Next, the electrode 38 is formed substantially at the center of the main light emitting surface.
In order to form, the buffer layer 32 and the etching marker layer 33 containing In are etched by the reactive ion etching method using chlorine gas. Here, in order to completely expose the etching marker layer 33 containing In, the etching is continued for 20 seconds after the signal of In is detected by the end point detection device of the dry etching device. Next, even if the etching marker layer 33 containing In is completely exposed, the etching is further continued, and after the signal of In is detected by the end point detection device of the dry etching device,
Etching is performed until there is no signal, and the first conductivity type nitride-based semiconductor layer 341 containing Al is exposed.

Next, Ti is formed to a thickness of 5 nm and Al is formed to a thickness of 5 nm as an electrode 310 on the exposed surface of the first-conductivity-type nitride semiconductor layer 341 containing Al by vapor deposition.
Au is used as a pad electrode 311 and has a thickness of 0.6 μm.
Form.

After that, the wafer is divided into approximately rectangular shapes each side of which is 300 μm square, the holding metal plate 39 side is mounted on the bottom of the cup of the lead frame, and A is placed on the pad electrode 311.
The u wire 312 is bonded.

The nitride-based semiconductor light emitting device of this example obtained as described above has a buffer layer 32 made of AlN.
The etching marker layer 33 containing In is formed between the n-type Al _0.1 Ga _0.9 N-containing Al-containing first-conductivity-type nitride semiconductor layer 341, whereby In is clearly detected by the end point detection device. Therefore, the first conductivity type nitride-based semiconductor layer 341 containing Al can be exposed with good reproducibility.

In the nitride semiconductor light emitting device of this embodiment, since the electrode 310 is in contact with the first conductivity type nitride semiconductor layer 341 containing Al, the etching marker layer 33 containing In is It does not have to have n-type conductivity, and may have high resistance, non-conductivity, or p-type conductivity.

(Embodiment 4) FIG. 10 shows a schematic sectional view of a nitride-based semiconductor light emitting device of this embodiment. The nitride-based semiconductor light-emitting device according to the present embodiment includes a base layer 48, a nitride-based semiconductor contact layer 47, a second conductivity type nitride-based semiconductor layer 46, an MQW light-emitting layer 45, which are provided on a holding metal plate 49. First conductivity type nitride semiconductor layer 44, first conductivity type nitride semiconductor layer 441 containing Al, etching marker layer 43 containing In, buffer layer 42, electrode 410, pad electrode 4
11 and Au wire 412.

Here, in this embodiment, the buffer layer 4
A part of the etching marker layer 43 containing 2 and In is etched, and the etching is finished in the middle of the etching marker layer 43 containing In. After the etching is finished, the etching marker layer 43 containing In is formed on the etching marker layer 43. It is characterized in that an electrode 410 is formed.

The manufacturing process of the nitride semiconductor light emitting device of this embodiment will be described below. First, a buffer layer 42 made of AlN having a thickness of 200 is formed on a substrate (not shown) made of Si.
nm, n-type In _0.3 Ga _0.7 N, an In-containing etching marker layer 43 having a thickness of 100 nm, and n-type Al _0.15 G
a _0.85 N Al-containing first conductivity type nitride semiconductor layer 441 having a thickness of 100 nm, n-type GaN first conductivity type nitride semiconductor layer 44 having a thickness of 300 nm, and MQW light emitting layer 45 having a thickness of 40 nm, p-type Al _0.15 Ga _0. consisting ₈₅ N second conductivity type nitride semiconductor layer 46 to a thickness of 5 nm, p
A wafer is formed by sequentially stacking a nitride-based semiconductor contact layer 47 made of type GaN to a thickness of 150 nm.

Next, using a vapor deposition method, Pd having a thickness of 30 n is formed on the nitride semiconductor contact layer 47 as an underlayer 48.
m and Au to a thickness of 200 nm, and Ni as a holding metal plate 49 having a thickness of 80 μm by electrolytic plating.
To form.

Next, the substrate (not shown) is removed over the entire surface using a hydrofluoric acid-based etching solution by using a normal photo process to expose the buffer layer 42.

Next, the electrode 41 is provided almost at the center of the main light emitting surface.
In order to form 0, the buffer layer 42 and the etching marker layer 43 containing In are partially removed by a dry etching method using chlorine gas, here a reactive ion etching method. Here, the In signal is detected by the end point detection device of the dry etching device, and the etching is finished in a state where the etching marker layer 43 containing In is exposed.

Next, as shown in FIG. 10, Hf was deposited to a thickness of 3 nm as an electrode 410 on the etching marker layer 43 containing In, which was exposed at the substantial center of the main light emitting surface, by using an evaporation method. With a thickness of 200 nm and Ti with a thickness of 50
Then, Au is formed as a pad electrode 411 to a thickness of 0.6 μm.

After that, the wafer is divided into a substantially rectangular shape with one side of 300 μm square, the holding metal plate 49 side is mounted on the bottom of the cup of the lead frame, and A is placed on the pad electrode 411.
The u wire 412 is bonded.

In the nitride-based semiconductor light-emitting device of this example obtained as described above, the etching of the etching marker layer 43 containing In is terminated halfway. Therefore,
By the etching marker layer 43 containing In which is a soft layer, the MQW light emitting layer 45 generated during the above etching
Not only can reduce the damage to In
Generated from strain or the like when forming the electrode 410 having good ohmic properties on the etching marker layer 43 containing
Mechanical damage to the W light emitting layer 45 can be reduced.

Therefore, also in this embodiment, it is possible to obtain a highly reliable nitride-based semiconductor light emitting device.

The embodiments and examples disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[0091]

As described above, according to the present invention, since the etching amount can be easily controlled, it is possible to provide a highly reliable nitride semiconductor light emitting device having a wide light emitting region and a large light output. You can Further, it is possible to provide a highly reliable nitride-based semiconductor light emitting device even when a high-resistance or non-conductive buffer layer is laminated on the substrate.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a nitride-based semiconductor light emitting device of Example 1.

FIG. 2 is a schematic conceptual view of a nitride-based semiconductor light emitting device of Example 1 during manufacturing.

FIG. 3 is a schematic conceptual view of a nitride-based semiconductor light emitting device of Example 1 in the process of being manufactured.

FIG. 4 is a schematic conceptual view of a nitride-based semiconductor light emitting device of Example 1 during manufacturing.

FIG. 5 is a schematic conceptual view of a nitride-based semiconductor light emitting device of Example 1 during manufacturing.

FIG. 6 is a schematic conceptual view of a nitride-based semiconductor light-emitting device of Example 1 during manufacturing.

FIG. 7 is a schematic cross-sectional view of a nitride-based semiconductor light emitting device of Example 2.

FIG. 8 is a schematic cross-sectional view of a nitride-based semiconductor light-emitting device of Example 2 before removing the substrate.

FIG. 9 is a schematic cross-sectional view of a nitride-based semiconductor light emitting device of Example 3.

FIG. 10 is a schematic cross-sectional view of a nitride-based semiconductor light emitting device of Example 4.

FIG. 11 is a schematic cross-sectional view of a conventional nitride-based semiconductor light emitting device using Si as a substrate.

[Explanation of symbols]

1,21 substrate, 2,22,32,42 buffer layer, 3,
An etching marker layer containing 23, 33, 43 In,
4,24,34,44 first conductivity type nitride-based semiconductor layer, 5,
25,35,45 MQW light emitting layer, 6,26,36,46
Second conductivity type nitride-based semiconductor layer, 7,27,37,47 Nitride-based semiconductor contact layer, 8,28,38,48 Underlayer, 9,29,39,49 Holding metal plate, 10,210,
310,410 electrodes, 11,211,311,411 pad electrodes, 12,212,312,412 Au wires, 34
A first conductivity type nitride semiconductor layer containing 1,441 Al,
100 upper clad layer, 200 light emitting layer, 300 lower clad layer, 400 buffer layer, 500 Si substrate, 600 p-type pad electrode, 700 n-type electrode.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5F004 AA02 CB15 CB18 DB19                 5F041 AA03 AA04 AA40 AA43 CA04                       CA05 CA12 CA34 CA40 CA46                       CA65 CA74 CA77 CA83 CA91                       CA98 CB15 CB36 DA16

Claims (10)

[Claims] 1. A first conductivity type nitride semiconductor including a second conductivity type nitride semiconductor layer, a light emitting layer, and a first conductivity type nitride semiconductor layer, which are sequentially formed above a holding metal plate. A nitride-based semiconductor light-emitting device comprising an etching marker layer containing In formed on the layer. 2. The nitride semiconductor light emitting device according to claim 1, wherein an electrode is formed on the etching marker layer containing In. 3. The nitride according to claim 1, wherein an electrode is formed on the first conductivity type nitride semiconductor layer exposed by partially removing the etching marker layer containing In. Physical semiconductor light emitting device. 4. The nitride-based semiconductor light emitting device according to claim 1, wherein the material of the etching marker layer containing In is InN, InGaN, or InGaAlN. 5. The nitride-based material according to claim 1, wherein a layer in contact with the etching marker layer containing In in the first-conductivity-type nitride semiconductor layer contains Al. Semiconductor light emitting device. 6. A step of sequentially forming a buffer layer, an etching marker layer containing In, a first conductivity type nitride semiconductor layer, a light emitting layer, a second conductivity type nitride semiconductor layer and a holding metal plate on a substrate. And a step of performing etching until at least a signal of In is detected when etching and removing at least a part of the substrate and the buffer layer, and a method for manufacturing a nitride-based semiconductor light-emitting device. 7. The nitride-based semiconductor light-emitting device according to claim 6, wherein etching is continued even after the In signal is no longer detected to expose the first-conductivity-type nitride-based semiconductor layer. Manufacturing method. 8. The method for manufacturing a nitride-based semiconductor light emitting device according to claim 6, wherein the buffer layer has high resistance or is non-conductive. 9. The material of the buffer layer is AlN or AlG
It is aN, The manufacturing method of the nitride type semiconductor light emitting element in any one of Claim 6 to 8. 10. The method for manufacturing a nitride-based semiconductor light-emitting device according to claim 6, wherein the substrate is made of Si.