JP2003158296A - Nitride semiconductor light emitting device chip and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the luminous efficiency and reliability of a nitride semiconductor device chip including a plurality of light emitting elements capable of emitting light of mutually different wavelengths and to realize a multicolor light emitting device chip with a small number of steps. provide. SOLUTION: The nitride semiconductor light emitting device chip includes a plurality of nitride semiconductor layers (31, 41, 51, 61, 71, etc.) stacked on the same main surface of the same support plate (1). Including nitride semiconductor light emitting devices, these light emitting devices include active layers (51, 52, 53) having different thicknesses and emit light of different wavelengths.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nitride semiconductor light emitting device chip including a plurality of light emitting elements that emit light of different wavelengths and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a light emitting device using a gallium nitride compound semiconductor, it is possible to emit light in a wide wavelength range from ultraviolet light to red light by adjusting the composition of the compound semiconductor in the light emitting layer. Full color displays incorporating LEDs (light emitting diodes) have also been developed. When an LED is used as a light source of a display, there is a method of forming one pixel by combining different LED chips that emit red, green, or blue light.

However, at least three L's are used in this method.
Since one pixel is formed by the ED chip, a large number of LED chips are required. Moreover, the size of one pixel becomes large, and it is difficult to obtain a fine image.

In order to realize a high-definition display,
Japanese Unexamined Patent Application Publication No. 9-162444 discloses a technique in which a plurality of light emitting elements that emit light of different wavelengths are built in one device chip. A schematic cross-sectional view 22 shows a structure of a multicolor light emitting semiconductor device chip using this technique. In the drawings of the present application, the same reference numerals indicate the same or corresponding parts. Further, in each drawing of the present application, dimensional relationships such as thickness and width are appropriately changed for clarity and simplification of the drawings, and actual dimensional relationships are not shown.

The multicolor light emitting semiconductor device chip shown in FIG. 22 has an n-type GaN layer 4 formed on a sapphire substrate 1,
InGaN active layers 51, 52, 53, p-type AlGaN layers 61, 62, 63, p-type GaN layers 71, 72, 73, p
It includes a mold electrode 8 and an n-type electrode 9.

In this method for manufacturing a multicolor light emitting device chip, first, the first group of nitride semiconductor layers 51, 61, 71 including the first active layer 51 is formed on the n-type GaN layer 4. A second active layer 52 having a band gap different from that of the first active layer 51 is formed on the n-type GaN layer 4 exposed by removing a part of the first group nitride semiconductor layer by etching. Group nitride semiconductor layer 5
2, 62, 72 are formed. Then, a third active layer 53 having a third active layer 53 having a bandgap different from those of the first and second active layers is formed on the exposed n-type GaN 4 by removing a part of the second group nitride semiconductor layer by etching. Three groups of nitride semiconductor layers 53, 63, 73 are formed. Finally, the p-type electrode 8 and the n-type electrode 9 are formed to obtain the multicolor light emitting device chip of FIG. As described above, conventionally, in order to make the band gaps of the active layers 51, 52, 53 different from each other, it is necessary to change the growth conditions (composition) of the respective active layers, and the film forming step and the etching step are repeated many times. Is repeated.

[0007]

When a plurality of light emitting elements emitting light of different wavelengths are manufactured on one light emitting device chip, the conventional manufacturing method as described above includes an active layer having a certain band gap. After forming the nitride semiconductor layer, the wafer is taken out from the film forming apparatus, the photolithography process and the etching process are performed, and then the wafer is carried into the film forming apparatus again to form a nitride semiconductor layer including an active layer having a different band gap. It is necessary to repeat the process. Therefore, the conventional manufacturing method has a problem that the number of steps is large and the productivity is low. Furthermore, the previously formed active layer is
Since it is exposed to a high temperature in the subsequent step of growing the nitride semiconductor layer including the active layer, there may be a problem that defects in the crystal are increased and the luminous efficiency and reliability of the device chip are lowered.

In view of the problems in the prior art as described above, the present invention improves the luminous efficiency and reliability of a nitride semiconductor device chip including a plurality of light emitting elements capable of emitting lights of different wavelengths, and at the same time, It is an object to provide a multicolor light emitting device chip in the number of steps.

[0009]

According to the present invention, a nitride semiconductor light emitting device chip includes a plurality of nitride semiconductor light emitting layers including a plurality of nitride semiconductor layers stacked above the same main surface of the same support plate. It is characterized in that it includes an element, and each of the light emitting elements includes an active layer having a different thickness and emits light having a different wavelength.

The active layers of these light emitting devices may have different light emitting areas. Also, the light emitting area of those active layers can be defined by a selective growth mask that limits the growth of the nitride semiconductor layer. The selective growth mask may be formed on the gallium nitride semiconductor layer formed over the entire main surface of the support plate. Furthermore, it is also possible to use a thick metal film as the support plate.

When manufacturing a nitride semiconductor light emitting device chip according to the present invention, a selective growth mask including a plurality of openings having different areas is formed above a support plate, and a nitride semiconductor layer is formed in the openings. By growing, light emitting layers having different thicknesses can be simultaneously formed.
The selective growth mask may be formed on the gallium nitride semiconductor layer formed over the entire main surface of the support plate.

The selective growth mask including a plurality of openings having different areas is formed above the same substrate, and a nitride semiconductor layer is grown in the openings to simultaneously form light emitting layers having different thicknesses. It is also possible to form a thick metal film as a supporting plate above the grown nitride semiconductor layer and then remove the substrate.

That is, according to the present invention, a plurality of nitride semiconductor layer growth regions having different areas separated by the selective growth mask are formed above the substrate, and the nitride semiconductor layers are formed in these regions. The active layers formed have different thicknesses. Then, active layers having different thicknesses can be simultaneously formed, and a plurality of light emitting elements capable of emitting light of different wavelengths can be formed on one device chip.

By the metal organic chemical vapor deposition method (MOCVD method) I
When an active layer made of nGaN is grown, generally, the emission wavelength depending on the mixed crystal ratio of InGaN is changed by changing the supply ratio of trimethylindium (TMI) and trimethylgallium (TMG). Even if the InGaN layer is grown with the supply ratio of, the emission wavelength can be changed by changing the layer thickness. That is, as shown in FIG. 20, even if the InGaN active layer is grown at a constant TMI and TMG supply ratio, the emission wavelength becomes longer if the thickness of the quantum well layer included in the active layer is increased. The emission wavelength is shortened by reducing the thickness of the well layer.

Here, the thickness of the active layer can be changed by using the selective growth mask as a means for changing the grown film thickness under the same film forming condition and changing the selective growth area. That is, if a selective growth mask that inhibits adhesion of raw materials is formed on the underlayer and a nitride semiconductor layer is deposited by MOCVD or the like, the nitride semiconductor layer is selectively formed in the opening region included in the mask. After the growth, the growth rate can be adjusted by the area ratio of the mask portion and the opening.

FIG. 21 is a conceptual graph showing the influence of the area ratio between the mask portion and the opening on the growth rate of the nitride semiconductor layer. That is, if the area of the opening is small, the growth rate increases, and if the area of the opening is large, the growth rate decreases.

Therefore, if a region having a different area ratio between the mask portion and the opening is formed above the substrate, the growth rate is high and the thickness of the active layer is large in the opening having a small area to obtain long wavelength light emission. On the contrary, in the large-area opening region, the growth rate is slow and the thickness of the active layer is small, so that light emission of short wavelength can be obtained. Then, a plurality of light emitting elements which emit light of different wavelengths can be manufactured over the same substrate by a single film forming process.

As described above, according to the present invention, a nitride semiconductor light emitting device chip including a plurality of light emitting elements capable of emitting different colors can be manufactured by an easy process.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described based on some more specific examples.

Example 1 FIG. 1 is a schematic sectional view showing an example of a nitride semiconductor light emitting device chip according to Example 1 of the present invention. This light emitting device chip comprises a Si substrate 1, a SiO ₂ mask 2, an InAlN buffer layer 3
1, 32, 33, n-type GaN layers 41, 42, 43, In
Multiple quantum well active layers 51, 52, 53 composed of GaN well layers and GaN barrier layers, p-type AlGaN layers 61, 62, 6
3, p-type GaN layers 71, 72, 73, p-type transparent electrode 8,
And n-type electrode 9.

Here, the emission wavelength of the nitride semiconductor light emitting device is as shown in FIG. 2 when the active layer is formed with the same In concentration.
As shown in 0, when the thickness of the active layer is large, the emission wavelength becomes long, and when the thickness is small, the wavelength becomes short.
For example, when the thickness t1 of the active layer 51 in FIG. 1 is 10 nm, red light emission having a wavelength of 630 nm is generated, when the thickness t2 of the active layer 52 is 5 nm, green light emission having a wavelength of 530 nm is generated, and the active layer 53 is formed. 4 when the thickness t3 is 3 nm
A blue emission of 70 nm is obtained. That is, the three primary colors of light can be emitted from one light emitting device chip shown in FIG.

When the multicolor light emitting device chip of FIG. 1 is manufactured, first, as shown in FIG. 2, light emitting regions are sectioned on a Si substrate 1 having a major surface with a crystallographic plane orientation of {111}. The mask 2 is formed. That is, a thickness of 0.3 to 4 μ is formed on the Si substrate 1 by a method such as sputtering or CVD
After forming the SiO ₂ film of m, the opening widths Sl, S2, and S3 are set to Sl <S2 <S3 by a normal photolithography process.
The stripe-shaped SiO ₂ mask 2 is formed so that For example, S1 = 20 μm, S2 = 40 μm, and S3 = 200 μm, and each mask stripe width is 50.
μm. At this time, if the mask stripe formation direction is formed parallel to the crystallographic direction <1-10> of the Si substrate, cracks caused by strain due to different physical properties of the Si substrate and the nitride semiconductor layer are suppressed. can do.

Then, on the Si substrate 1 having the SiO ₂ mask 2 shown in FIG. 2, a plurality of nitride semiconductor layers shown in FIG. 1 are formed by MOCVD. Trimethyl aluminum (TMA) is a raw material of Al, trimethyl gallium (TMG) is a raw material of Ga, trimethyl indium (TMI) is a raw material of In, ammonia (NH ₃ ) is a raw material of N, and n-type dopant is Silane (Si
H ₄ ), and cyclopentadienyl magnesium (Cp ₂ Mg) is used as a p-type dopant to grow the respective nitride semiconductor layers.

Here, as the buffer layers 31, 32 and 33, Si-doped n-type InAlN is used in order to obtain a crystal thin film having conductivity and good characteristics. That is, the substrate temperature is set to 650 ° C. and TMA is added to 0.7 μmol.
/ Min, TMI 0.8 μmol / min, NH ₃ 1 l / min
And SiH ₄ at a rate of 1 nmol / min,
Si-doped n-type InAlN buffer layers 31, 32, 3
Grow 3

Next, at a substrate temperature of 1050 ° C., TM
G for 50 μmol / min, NH ₃ for 7 l / min, and Si
H ₄ is supplied at a rate of 10 nmol / min to grow the n-type GaN layers 41, 42 and 43. Next, the substrate temperature 750
TMG 7μmol / min, TMI 17μ
The InGaN quantum well active layer is grown by supplying mol / min and NH ₃ at a rate of 20 l / min. Next, at a substrate temperature of 840 ° C., TMG was added at 7 μmol / min and N 2
H ₃ is supplied at a rate of 20 l / min to grow a GaN barrier layer. Growth of these quantum well layers and barrier layers is repeated to form multiple quantum well light emitting layers 51, 52, 53. Next, at a substrate temperature of 1000 ° C., TMG is 7 μm.
mol / min, TMA 0.7 μmol / min, Cp ₂ Mg
At a rate of 0.2 μmol / min and NH ₃ at a rate of 3 l / min to form p-type AlGaN layers 61, 62 and 63. Next, at a substrate temperature of 1000 ° C., TMG is added to 5
0 μmol / min, NH ₃ 7 l / min, and Cp ₂ Mg at a rate of 2 μmol / min to supply the p-type GaN layer 71,
72 and 73 are grown. After that, by forming the p-type transparent electrode 8 and the n-type electrode 9, the nitride semiconductor light emitting device shown in FIG. 1 is obtained.

When MOCVD growth of the nitride semiconductor layer is performed on the substrate 1 on which the SiO ₂ mask 2 having a plurality of openings having different widths is formed as described above, in the wide opening area as shown in FIG. The growth rate becomes slower, and the growth rate becomes faster in the narrow opening region. Therefore, the narrow Sl
The grown film thickness is large in the portion, and then the grown film thickness is reduced in the order of the S2 portion and the S3 portion.

As a result, the active layers 51, 52 and 53 are grown with the same ratio of TMI and TMG, but the emission wavelength is shortened in the order of Sl, S2 and S3 due to the difference in the layer thickness. You can FIG. 3 shows the relationship between the mask opening width and the emission wavelength when the InGaN quantum well active layer is grown under the above film forming conditions.

In the graph of FIG. 3, w represents the stripe width of the SiO ₂ mask, and in this embodiment the SiO ₂ mask width w is 50 μm. Therefore, the opening widths Sl, S
If S2 and S3 are set to 20 μm, 40 μm, and 200 μm, respectively, the wavelength is 6 from the Sl region in the same film formation time.
A red emission of 30 nm is obtained, and the wavelength is 5 from the S2 region.
Green emission of 30 nm is obtained, and blue emission of 470 nm wavelength can be obtained from the S3 region.

Example 2 FIG. 4 is a schematic sectional view showing an example of a nitride semiconductor light emitting device chip according to Example 2. This light emitting device chip is composed of Si substrate 1, S
iO ₂ mask 2, InAlN buffer layer 3, n-type Ga
N layer 4, 41, 42, 43, InGaN well layer and GaN
Multi-quantum well active layers 51, 52, 53 composed of barrier layers,
p-type AlGaN layers 61, 62, 63, p-type GaN layer 7
1, 72, 73, a p-type transparent electrode 8 and an n-type electrode 9. The relationship between the thicknesses tl, t2, and t3 of the active layers 51, 52, and 53 in FIG. 4 is the same as in the first embodiment, and the width of the opening of the SiO ₂ mask 2 is Sl <S2 <S3.
S1 = 20 μm, S2 = 40 μm, and S3 = 200 μm so that the mask stripe width w =
It is set to 50 μm. Also in the light emitting device chip according to the second embodiment, red, green and blue lights are emitted from the active layers 51, 52 and 53, respectively.

In the method of manufacturing the device chip of FIG. 4, first, as shown in FIG. 5, 1 is formed on the {111} Si substrate 1.
InAlN buffer layer 3, n
The type GaN layer 4 is formed. Next, as shown in FIG.
The SiO ₂ mask 2 is formed on the type GaN layer 4. The mask stripe in the second embodiment is also formed parallel to the <1-10> direction of the Si substrate as in the first embodiment.

After that, in the second MOCVD growth, the n-type GaN layers 41, 42, 43, InGaN and Ga were formed.
N multiple quantum well active layers 51, 52, 53, p-type AlG
aN layers 61, 62, 63 and p-type GaN layers 71, 7
2, 73 are sequentially formed. The film forming conditions here are the same as those in the first embodiment. After that, the p-type transparent electrode 8 and n
The mold electrode 9 is formed, and the nitride semiconductor light emitting device of FIG. 4 is obtained.

In the hetero growth such as the epitaxial growth of the nitride semiconductor layer on the Si substrate 1, the buffer layer 3 is used.
It is desirable to strictly control the thickness of the. As in Example 2, by growing the buffer layer 3 on the entire surface of the substrate 1 instead of the selective growth, the layer thickness can be made uniform and the optimum value. Therefore, after that, the buffer layer 3 is formed in the selective growth region. The crystallinity of the nitride semiconductor layer grown above may also be improved.

Before forming the mask 2, the n-type GaN layer 4 is formed.
In the case of forming, it is possible to use an insulating substrate such as sapphire instead of the conductive Si substrate 1. In that case, the n-type electrode may be formed by dry etching a part of the nitride semiconductor layer which is not the light emitting region to expose a part of the n-type GaN layer 4 and forming the n-type electrode on the exposed part.

(Embodiment 3) FIG. 7 is a schematic sectional view showing an example of a nitride semiconductor light emitting device chip according to Embodiment 3. This light emitting device chip includes InAlN buffer layers 31, 32 and 33, n-type GaN layers 41 and 42,
43, a multi-quantum well active layer 51, 52, 53 composed of an InGaN well layer and a GaN barrier layer, a p-type AlGaN layer 6
1, 62, 63, the p-type GaN layers 71, 72, 73 are p
It includes a mold electrode 8, a metal plating film 80, and an n-type electrode 9. The thicknesses and widths of the active layers 51, 52, 53 in the light emitting device chip of the third embodiment are the same as those in the first embodiment, and have a relationship of tl>t2> t3, and the widths are 20 μm, 40 μm, and 200 μm, respectively. is there. Then, red, green, and blue light emissions are obtained from the active layers 51, 52, and 53, respectively.

In the fabrication of the device chip of FIG. 7,
Similar to the case of FIG. 2 of Example 1, first, the SiO ₂ mask 2 is formed on the {111} Si substrate 1. Each stripe of the SiO ₂ mask 2 has a width of 50 μm, and the opening width Sl =
20 μm, S2 = 40 μm, and S3 = 200 μm are set. The direction of each stripe is <1- of the Si substrate.
Parallel to 10>.

Next, as shown in FIG.
1N buffer layer 31, 32, 33, 34, n-type GaN
Layers 41, 42, 43, InGaN and GaN multiple quantum well active layers 51, 52, 53, p-type AlGaN layers 61, 6
2, 63 and p-type GaN layers 71, 72, 73 are sequentially grown. At this time, the InAlN buffer layer can be grown on the SiO ₂ mask 2 by reducing the growth rate. Next, after the p-type electrode 8 is formed on the p-type GaN layers 71, 72, 73, a metal plating film 80 is formed on the p-layer side by electrolytic plating or electroless plating to a thickness of about 100 μm.

After that, the Si substrate 1 in FIG. 8 is removed by etching. If wet etching is performed with hydrofluoric nitric acid, the SiO ₂ film 2 is removed by etching at the same time as the Si substrate 1. At this time, the InAlN layer 34 is formed on the SiO ₂ film 2.
Since this is formed, this serves as an etching stop layer, and only the Si substrate 1 and the SiO ₂ film 2 are removed by etching without etching the metal plating film 80. Finally, the exposed InAlN buffer layer 3
The n-type electrode 9 is formed on 1, 32 and 33 to obtain the nitride semiconductor light emitting device of FIG. 7.

When the Si substrate is removed as in the light emitting device chip according to the third embodiment, since there is no Si substrate that absorbs the light emitted from the active layer, a strong light emission intensity can be obtained.

(Embodiment 4) FIG. 9 is a schematic sectional view showing an example of a nitride semiconductor light emitting device chip according to Embodiment 4. This device chip has an n-type GaN layer 41,
42, 43, multiple quantum well active layers 51, 52, 53 composed of InGaN well layers and GaN barrier layers, p-type AlGaN
Layers 61, 62, 63, p-type GaN layers 71, 72, 73,
It includes a p-type electrode 8, a metal plating film 80, and an n-type electrode 9. In the active layers 51, 52 and 53 of the light emitting device chip according to the fourth embodiment, the layer thickness relationship is set to tl>t2> t3 and the widths are set to 20 μm, 40 μm and 200 μm, respectively, as in the case of the first embodiment. It is set. Then, red, green, and blue light emissions are obtained from the active layers 51, 52, and 53, respectively.

In manufacturing the device chip shown in FIG.
Similar to the case of FIG. 2 of Example 1, first, the SiO ₂ mask 2 is formed on the {111} Si substrate 1. Each stripe of the SiO ₂ mask 2 has a width of 50 μm, and the opening width Sl =
20 μm, S2 = 40 μm, and S3 = 200 μm are set. The direction of each mask stripe is parallel to <1-10> of the Si substrate.

Next, as in the case of FIG. 8, buffer layers 31, 3 are formed on the Si substrate 1 on which the SiO ₂ mask 2 is formed.
Deposit 2, 33, 34. However, in the fourth embodiment, AlN is used as the buffer layer instead of InAlN. Also in this case, the AlN buffer layer can be grown on the SiO ₂ mask 2 by decreasing the growth rate.

After that, the n-type GaN layers 41, 42, 43,
InGaN and GaN multiple quantum well active layers 51, 52,
53, p-type AlGaN layers 61, 62 and 63, and p-type GaN layers 71, 72 and 73 are sequentially grown. Next, after forming the p-type electrode 8 on the p-type GaN layers 71, 72, 73, a metal plating film 80 having a thickness of about 100 μm is formed on the p-layer side.
To plate. Next, when wet etching is performed with hydrofluoric nitric acid, the SiO ₂ film 2 is removed by etching simultaneously with the Si substrate 1. Even in this case, Al existing on the SiO ₂ film
The N layer serves as an etching stop layer, and the Si substrate 1 and S
Only the iO ₂ film 2 is removed by etching.

Next, the non-conductive AlN buffer layers 31, 32, 33, and 34 are removed by dry etching, and then the n-type electrode 9 is formed on the n-type GaN layers 41, 42, and 43. A nitride semiconductor light emitting device is obtained.

When the nitride semiconductor layer was grown by MOCVD as in Example 4, AlN was used as a buffer layer.
GaN layer or I grown on the
The crystal quality of the multiple quantum well active layer of nGaN and GaN is improved, and stronger emission intensity can be obtained. Also, A
Since the 1N buffer layer is removed, a light emitting device chip with a low driving voltage can be obtained.

(Embodiment 5) FIG. 10 is a schematic sectional view showing an example of a nitride semiconductor light emitting device chip according to Embodiment 5. This device chip has an n-type GaN layer 4
2, 43, a multiple quantum well active layer 52, 53 composed of an InGaN well layer and a GaN barrier layer, a p-type AlGaN layer 62,
63, p-type GaN layers 72 and 73, p-type electrode 8, metal plating film 80, and n-type electrode 9. The widths of the active layers 52 and 53 in FIG. 10 are 30 μm and 200 μm, respectively.
m. Yellow light and blue light are emitted from the active layers 52 and 53, respectively. Yellow light and blue light have a complementary color relationship with each other, and white light emission can be obtained by simultaneously emitting light of these colors.

In the method of manufacturing the light emitting device chip of FIG. 10, first, as shown in FIG.
1} On the Si substrate 1, the stripe width is 50 μm,
The SiO ₂ mask 2 is formed so that the opening widths are S2 = 30 μm and S3 = 200 μm and the stripe direction is parallel to the <1-10> direction of the Si substrate.

Next, as shown in FIG.
AlN buffer layers 32, 33, 34, n-type GaN layers 42, 43, I on the Si substrate 1 on which the O ₂ mask 2 is formed.
nGaN and GaN multiple quantum well active layers 52, 53, p
-Type AlGaN layers 62 and 63 and p-type GaN layers 72 and 73 are sequentially grown. Again, the AlN buffer layer can be grown on the SiO ₂ mask 2 by reducing its growth rate. Next, after forming the p-type electrode 8 on the p-type GaN layers 72 and 73, a metal plating film 80 is plated on the p-layer side to a thickness of about 100 μm.

After that, when wet etching is performed with hydrofluoric nitric acid, the SiO ₂ film 2 is removed by etching simultaneously with the Si substrate 1. Here, the Al existing on the SiO ₂ film 2
The N layer 34 functions as an etching stop layer, and the metal plating film 8 is not etched and the Si substrate 1 and SiO ₂
Only the film 2 is etched away. Next, after removing the non-conductive AlN buffer layers 32 and 33 by dry etching, the n-type electrode 9 is formed on the n-type GaN layers 42 and 43.
The nitride semiconductor light emitting device of FIG. 10 is obtained by forming.

When blue light and yellow light are emitted at the same time to obtain white light, the luminous efficiency of blue light is about 1/4 of that of yellow light, so that the blue light intensity needs to be higher than the yellow light intensity. Therefore, under the condition of the same light emitting area, it is necessary to increase the current density in the blue light emitting region as compared with the yellow light emitting region. However, in the light emitting device chip of FIG. 10, since the area of the blue light emitting region 53 is made larger than that of the yellow light emitting region 52, it is possible to match the luminosity of each light emission under the same current density condition. . That is,
It is not necessary to increase the current density of the blue light emitting region 53,
A white light emitting device chip having a long life can be obtained.

The light emitting device chip of FIG. 10 can emit white light without the need for a fluorescent material that converts the wavelength of light emitted from the active layer, and can be manufactured by using a single MOCVD growth step. Therefore, it has excellent productivity.

(Embodiment 6) In Embodiments 1 to 5, the growth rate of the nitride semiconductor layer in the opening region is adjusted by changing the opening width while keeping the mask stripe width constant. However, it is also possible to adjust the growth rate by changing the mask stripe width while keeping the opening width constant.

FIG. 13 is a schematic sectional view showing an example of a nitride semiconductor light emitting device chip according to the sixth embodiment.
This light emitting device chip includes n-type GaN layers 41, 42,
43, a multi-quantum well active layer 51, 52, 53 composed of an InGaN well layer and a GaN barrier layer, a p-type AlGaN layer 6
1, 62, 63, p-type GaN layers 71, 72, 73, p-type electrode 8, metal plating film 80, and n-type electrode 9. In FIG. 13, the widths of the active layers 51, 52, and 53 are all 70 μm, and the relationship between the layer thicknesses thereof is tl <
t2 <t3 and actually tl = 3 nm, t2 = 5n
m and t3 = 10 nm, and blue, green, and red light emissions are obtained from the active layers 51, 52, and 53, respectively.

In manufacturing the light emitting device chip of FIG.
First, as shown in FIG. 14, {111} S
Stripe width wl = 20 μm, w2 = 1 on i substrate 1
00 μm, w3 = 200 μm, opening width Sl = S2 = S3
= 70μm and SiO ₂The mask 2 is formed. Ma
The direction of the stripe of the mask is <1-10> of the Si substrate.
Set parallel.

Next, as shown in FIG.
AlN buffer layers 31, 32, 33, 34, n-type GaN layers 41, 4 on the Si substrate on which the O ₂ mask 2 is formed.
2, 43, InGaN and GaN multiple quantum well active layer 5
1, 52, 53, p-type AlGaN layers 61, 62, 63,
Then, the p-type GaN layers 71, 72, 73 are sequentially grown. Again, the AlN buffer layer can also be grown on the SiO ₂ mask 2 by reducing its growth rate. Next, the p-type electrode 8 is formed on the p-type GaN layer 7
After being formed on 1, 72, 73, a metal plating film 80 is plated on the p layer side to a thickness of about 100 μm.

After that, wet etching is performed with hydrofluoric nitric acid, so that the SiO ₂ film 2 is simultaneously removed by etching with the Si substrate 1. Also at this time, the AlN layer 34 on the SiO ₂ film 2 functions as an etching stop layer,
Only the Si substrate 1 and the SiO ₂ film 2 are removed by etching without etching the metal plating film 80. Next, the non-conductive AlN buffer layers 31, 32, 33, and 34 are removed by dry etching, and then the n-type electrode 9 is formed on the n-type GaN layers 41, 42, and 43. A nitride semiconductor light emitting device is obtained.

As in the sixth embodiment, the active layers 51, 52 and 53 having different thicknesses can be obtained by changing the mask stripe width w while keeping the width of the opening of the SiO ₂ mask constant.
Can be formed at the same time, and a light-emitting device chip capable of emitting lights having different wavelengths can be manufactured by using one film formation process.

In Examples 1 to 6 above, SiO
_Although the stripe shape was used as the opening shape of the ₂ mask 2, the growth rate of the nitride semiconductor film growing in the opening is different if the area ratio of the opening and the SiO ₂ mask is different. As shown in FIG. 19, the shape of the opening of the mask 2 can be any shape such as a quadrangle, a triangle, a circle, or a rhombus. 16 to 19, reference numeral 10 represents a wire bonding point.

[0058]

As described above, according to the present invention, the luminous efficiency and reliability of a nitride semiconductor device chip including a plurality of light emitting elements capable of emitting light of different wavelengths are improved and the number of steps is reduced. Thus, it becomes possible to provide a multicolor light emitting device chip.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a nitride semiconductor light emitting device chip according to Example 1 of the present invention.

FIG. 2 is a schematic cross-sectional view for explaining a manufacturing process of the multicolor light emitting device chip of Example 1.

3 is a schematic diagram of Si in the multicolor light emitting device chip of FIG.
6 is a graph showing the relationship between the opening width of the O ₂ mask and the emission wavelength.

FIG. 4 is a schematic cross-sectional view showing a nitride semiconductor light emitting device chip according to Example 2.

FIG. 5 is a schematic cross-sectional view for explaining a manufacturing process of a multicolor light emitting device chip of Example 2.

FIG. 6 is a schematic cross-sectional view for explaining a manufacturing process of a multicolor light emitting device chip of Example 2.

7 is a schematic sectional view showing a nitride semiconductor light emitting device chip according to Example 3. FIG.

FIG. 8 is a schematic cross-sectional view for explaining a manufacturing process of the multicolor light emitting device chip of Example 3.

FIG. 9 is a schematic cross-sectional view showing a nitride semiconductor light emitting device chip according to Example 4.

FIG. 10 is a schematic cross-sectional view showing a nitride semiconductor light emitting device chip according to Example 5.

FIG. 11 is a schematic cross-sectional view for explaining a manufacturing process of a multicolor light emitting device chip of Example 5.

FIG. 12 is a schematic cross-sectional view for explaining a manufacturing process of a multicolor light emitting device chip of Example 5.

FIG. 13 is a schematic sectional view showing a nitride semiconductor light emitting device chip according to Example 6.

FIG. 14 is a schematic cross-sectional view for explaining the manufacturing process for the multicolor light-emitting device chip of Example 6.

FIG. 15 is a schematic cross-sectional view for explaining the manufacturing process for the multicolor light-emitting device chip of Example 6.

FIG. 16 is a schematic top view showing the shape of a light emitting portion in a multicolor light emitting device chip according to another embodiment.

FIG. 17 is a schematic top view showing the shape of a light emitting portion in a multicolor light emitting device chip according to another embodiment.

FIG. 18 is a schematic top view showing the shape of a light emitting portion in a multicolor light emitting device chip according to another embodiment.

FIG. 19 is a schematic top view showing the shape of a light emitting portion in a multicolor light emitting device chip according to another embodiment.

FIG. 20 is a graph showing the relationship between the thickness of the quantum well active layer and the emission wavelength.

FIG. 21 is a conceptual graph showing the influence of the area ratio between the mask portion and the opening on the growth rate of the nitride semiconductor layer.

FIG. 22 is a schematic cross-sectional view showing a conventional multicolor light emitting device chip.

[Explanation of symbols]

1 Si substrate, 2 SiO ₂ film, 31, 32, 33, 3
4 n-type InAlN buffer layer, 41, 42, 43
n-type GaN layer, 51, 52, 53 InGaN and GaN
Multiple quantum well active layer, 61, 62, 63 AlGaN
Clad layer, 71, 72, 73 p-type GaN layer, 8 p
Type electrode, 80 metal plating film, 9 n type electrode.

Claims (8)

[Claims] 1. A plurality of nitride semiconductor light emitting devices including a plurality of nitride semiconductor layers stacked on the same main surface of the same support plate, wherein the plurality of light emitting devices include active layers having different thicknesses. A nitride semiconductor light emitting device chip, which is characterized in that it emits light of different wavelengths. 2. The nitride semiconductor light emitting device chip of claim 1, wherein the plurality of light emitting elements include the active layers having different light emitting areas. 3. The nitride semiconductor light emitting device chip according to claim 2, wherein the light emitting area of the active layer is defined by a selective growth mask that limits the growth of the nitride semiconductor layer. 4. A gallium nitride semiconductor layer is formed on the entire surface of the main surface of the support plate, and the selective growth mask is formed on the gallium nitride semiconductor layer.
7. The nitride semiconductor light emitting device chip according to. 5. The nitride semiconductor light emitting device chip according to claim 1, wherein the support plate is made of metal. 6. The method for manufacturing a nitride semiconductor light emitting device chip according to claim 3, wherein the selective growth mask including a plurality of openings having different areas is formed above the support plate, A method of manufacturing, wherein the light emitting layers having different thicknesses are simultaneously formed by growing the nitride semiconductor layer in the opening. 7. The method for manufacturing a nitride semiconductor light emitting device chip according to claim 4, wherein the selective growth mask including a plurality of openings having different areas is formed on the gallium nitride semiconductor layer. Then, the light emitting layers having different thicknesses are simultaneously formed by growing the nitride semiconductor layer in the opening. 8. The method for manufacturing a nitride semiconductor light emitting device chip according to claim 5, wherein the selective growth mask including a plurality of openings having different areas is formed on the same substrate, The nitride semiconductor layer is grown in the opening to simultaneously form the light emitting layers having different thicknesses, a metal thick film as the supporting plate is formed above the nitride semiconductor layer, and then the substrate is removed. A manufacturing method characterized by: