JP2003209284A - Optical semiconductor element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical semiconductor element, which is reduced in the movement of dislocation from a substrate to the other layer, small in an element size, and easy in wiring work. <P>SOLUTION: This optical semiconductor element is provided with a substrate 2 composed of single crystal of Si or GaAs, a plurality of insulating layers 3 which are aligned being spaced apart from each other by gaps 4 between them and formed in a stripe type on the substrate 2, a growth layer 5 which is arranged so as to cover the gaps 4 and the insulating layers 3 and composed of III nitride compound, and a light emitting layer 6 which is arranged above the growth layer 5. Further, a first matching layer 12 composed of single crystal of Al is arranged between a surface of the substrate 2 and backs of the insulating layers 3, and a second matching layer 13 is arranged which is formed so as to cover the gaps 4 and the insulating layers 3, positioned below the growth layer 5 and composed of single crystal of GaAlN. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an optical semiconductor device.

[0002]

2. Description of the Related Art Conventionally, an element of this type is disclosed in, for example, Japanese Patent Laid-Open No. 6-268259. According to this publication, as shown in the sectional view of FIG.
A buffer layer 112, a contact layer 113, and
The clad layer 114, the light emitting layer 115, and the clad layer 11
6, a contact layer 117, and a P electrode 118 are provided. An N electrode 119 is provided on the lower surface of the contact layer 113. The optical semiconductor element 120 is configured by these layers.

[0003]

However, in the above optical semiconductor device 120, the sapphire substrate 111 and the buffer layer 1 are used.
12 has a greatly different lattice constant. As a result, dislocations (strains due to differences in lattice constants) move upward from the sapphire substrate 111. The moving dislocation density is as large as about 10 ¹⁰ cm ^-2 . Impurities are likely to collect at this dislocation portion. As a result, there is a first drawback that impurities penetrate into the light emitting layer 115 and the light output deteriorates.

Further, the optical semiconductor element 120 has a second defect that the outer size of the element becomes large because the outer shape has a step. Furthermore, the P electrode 118 and the N electrode 11
Since 9 is on the front side, connect with 2 wires,
There is a third drawback that wiring is troublesome.

In view of the above-mentioned conventional drawbacks, the present invention provides an optical semiconductor device in which dislocation migration from the substrate to other layers is small, the device size is small, and wiring work is easy.

[0006]

In order to solve the above problems, according to the present invention of claim 1, a single crystal of Si or GaAs is used.
A plurality of insulating layers arranged in a stripe pattern on the substrate and spaced apart from each other by a substrate made of a single crystal, and a group III nitride that is provided so as to cover the gap and the insulating layer. A growth layer made of a compound and a light emitting layer provided above the growth layer were provided.

According to the second aspect of the present invention, a first single crystal of Al is provided between the front surface of the substrate and the back surface of the insulating layer.
A matching layer is provided, and a second matching layer made of a GaAlN single crystal is provided so as to cover the gap and the insulating layer and is located below the growth layer.

In the present invention of claim 3, the insulating layer is formed in a substantially trapezoidal cross section.

According to a fourth aspect of the present invention, the surface side of the substrate is formed into a plurality of substantially trapezoidal portions with cross sections spaced from each other.
The insulating layer is formed on the upper surface of the trapezoidal portion.

According to the fifth aspect of the present invention, a plurality of insulating layers arranged in stripes inside the substrate are aligned with a substrate made of a single crystal of Si or a single crystal of GaAs with a gap therebetween. And a growth layer formed on the substrate and made of a Group III nitride compound, and a light emitting layer provided above the growth layer.

According to a sixth aspect of the present invention, there is provided a first matching layer which is formed so as to cover the gap and the back surface of the insulating layer and is located on the substrate and which is made of an Al single crystal. A second matching layer made of GaAlN single crystal was provided between the front surface of the insulating layer and the back surface of the growth layer.

According to the present invention of claim 7, the width of the gap and the width of the insulating layer are determined according to the ratio of the thermal expansion coefficient of the growth layer or the insulating layer to the thermal expansion coefficient of the substrate. The proportion was determined.

According to the present invention of claim 8, a plurality of first mask layers are provided above the gap so as to cover the gap and are provided in the growth layer.

In the present invention of claim 9, the first mask layer is formed in a substantially trapezoidal cross section.

According to a tenth aspect of the present invention, at least the openings are provided above the openings so as to cover the openings between the first mask layers, are provided in the growth layer, and have a substantially trapezoidal cross section. A plurality of second mask layers was provided.

According to the present invention of claim 11, Si doped with the first dopant or Ga doped with the second dopant is used.
A plurality of insulating layers arranged in a stripe pattern on the substrate and spaced apart from each other by a substrate made of As, and provided so as to cover the gap and the insulating layer;
A growth layer made of a Group III nitride compound and a light emitting layer provided above the growth layer were provided.

According to the twelfth aspect of the present invention, a back electrode is provided on the back surface of the substrate.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an optical semiconductor element 1 according to a first embodiment of the present invention will be described with reference to the sectional view of FIG. In FIG. 1, a substrate 2 is obtained by dividing a wafer made of single crystal Si into a predetermined size. That is, the substrate 2 is Si
Consisting of a single crystal. Although a substrate made of GaAs single crystal may be used, the substrate 2 is made of Si single crystal in the following description.

The insulating layer 3 is made of, for example, SiO _2, and is arranged in a spaced-apart relationship with each other with a gap 5 therebetween, and is provided in a stripe shape on the substrate 2.

The growth layer 5 is made of, for example, N-type GaN,
The cross-sectional shape is substantially convex, and is provided so as to cover the gap 4 and the insulating layer 3. Thus, the growth layer 5 is made of a Group III nitride compound.

The light emitting layer 6 is made of, for example, InGaN and is formed on the growth layer 5.

The cladding layer 7 is made of, for example, P-type GaAlN, and is formed on the light emitting layer 6. Contact layer 8
Is made of, for example, P-type GaAlN, and is formed on the cladding layer 7.

The P electrode 9 is made of gold or the like, and the contact layer 8
Is formed on. Thus, the light emitting layer 6 is formed above the growth layer 5.

The N electrode 10 is formed on the surface of the growth layer 5 which has a low position. The optical semiconductor element (light emitting diode) 1 is composed of the above layers.

In the optical semiconductor element 1, the movement of dislocations upward from the substrate 2 is blocked by the insulating layer 3.
Therefore, dislocations move only through the gaps 4 between the insulating layers 3. As a result, the movement of dislocations from the substrate 2 to the growth layer 5 is significantly smaller than in the conventional case.

Moreover, since a current flows through the P electrode 9, the contact layer 8, the cladding layer 7, the light emitting layer 6 and the growth layer 5, and the N electrode 10 by the applied voltage, there is no problem in the current path.

Next, an optical semiconductor device 11 according to the second embodiment of the present invention will be described with reference to FIG. In FIG. 1, the first matching layer 12 is provided between the front surface of the substrate 2a and the back surface of the insulating layer 3 and is made of a single crystal of Al.

The second matching layer 13 includes the gap 4 and the insulating layer 3.
And is formed under the growth layer 5a to cover G
It is composed of a single crystal of aAlN.

The other light emitting layer 6, cladding layer 7, contact layer 8, P electrode 9 and N electrode 10 are the same layers as the optical semiconductor element 1. Due to the above layers, this optical semiconductor device 11
Is configured.

With respect to the first matching layer 12, triisobutyl is thermally vaporized by a bubbler on the substrate 2a by a heat activated CVD apparatus using argon as a carrier gas. Then, GTC (Gas Temperature Con
troller, gas temperature controller). Thereafter, the activated material becomes a single crystal of aluminum (first matching layer 12) on the heated substrate 2a.

The lattice constant of Si constituting the substrate 2a is 5.
43 Å, Al constituting the first matching layer 12
Has a lattice constant of 4.05 angstroms, and the lattice mismatch rate is small.

On the other hand, the conventional optical semiconductor device 120
In this case, the lattice mismatch rate between the sapphire substrate 111 and the buffer layer 112 is large. As a result, the lattice mismatch rate between the substrate 2a of the present invention and the first matching layer 12 is about half that of the conventional one.

The upper part of the insulating layer 3 is covered with the second matching layer 13 grown in the lateral direction, and the upward movement of the dislocations from the substrate 2a through the first matching layer 12 is caused by the insulating layer. Blocked by 3.

Therefore, the dislocations move only through the gap 4. As a result, the movement of dislocations from the substrate 2a to the growth layer 5 is about 3 × 10 ⁶ cm ^-2 , which is significantly smaller than the conventional 10 ¹⁰ cm ^-2 .

Next, the optical semiconductor element 14 according to the third embodiment of the present invention will be described with reference to the sectional view of FIG. In FIG. 2, the insulating layer 3a is formed on the substrate 2 in a stripe shape, spaced apart from each other and aligned with each other.

Each insulating layer 3a has a substantially trapezoidal cross section. The growth layer 5b includes the gap 4a and the insulating layer 3
It is formed so as to cover a. The other layers are the same as the layers used in the optical semiconductor element 1.

By thus forming the insulating layer 3a into a trapezoidal shape, the ratio of the area occupied by the insulating layer 3a on the substrate 2 is reduced, and the lattice mismatch rate is lowered. In addition, as in the past,
A buffer layer 112 is formed on the entire surface of the sapphire substrate 111.
Is provided, the lattice mismatch rate is large. That is,
The lattice mismatch rate is substantially proportional to the area ratio of the insulating layer 3a on the substrate 2.

Next, the optical semiconductor element 15 according to the fourth embodiment of the present invention will be described with reference to the sectional view of FIG. In FIG. 3, the insulating layer 3b is formed in stripes on the substrate 2 so as to be aligned apart from each other with a gap 4b.

The insulating layer 3b has a substantially trapezoidal cross section. The growth layer 5c includes the gap 4b and the insulating layer 3b.
Is formed so as to cover. The other layers are the same as the layers used in the optical semiconductor element 1.

The thermal expansion coefficient of the growth layer 5c (made of N-type GaN or the like) is 5.59 × 10 ⁻⁶ / K, and the thermal expansion coefficient of the substrate (made of Si single crystal) 2 is 3.59 × 10 ^−6. The width A of the gap 4b and the width B of the insulating layer 3b are equal to the ratio of / K.
Is determined. That is, A: B = 5.59 × 10 ⁻⁶ : 3.59 × 10 ⁻⁶ ≈6: 4 In this way, when the insulating layer 3b is formed on the substrate 2, as in the above equation, The ratio between the width A and the width B is determined according to the ratio of the respective thermal expansion coefficients of the growth layer 5c and the substrate 2. With this configuration, the optical semiconductor element 15 is prevented from warping (warping) due to temperature rise.

Next, the optical semiconductor element 16 according to the fifth embodiment of the present invention will be described with reference to the sectional view of FIG. In FIG. 4, the insulating layer 3c is formed in stripes on the substrate 2 so as to be aligned with each other with a gap 4c therebetween.

Each insulating layer 3c has a substantially triangular cross section. The growth layer 5d is formed so as to cover the gap 4c and the insulating layer 3c. The other layers are the same as the layers used in the optical semiconductor element 1.

Thermal expansion coefficient of growth layer 5d (N-type GaN) 5.
59 × 10 ^-6 / K and substrate (consisting of Si single crystal) 3
The ratio of the width C of the gap 4c to the width D of the insulating layer 3c is determined so as to be equal to the ratio of the thermal expansion coefficient of 3.59 × 10 ⁻⁶ / K. That is, C: D = 5.59 × 10 ⁻⁶ : 3.
59 × 10 ⁻⁶ ≈6: 4 Next, the optical semiconductor element 17 according to the sixth embodiment of the present invention will be described with reference to the sectional view of FIG. In FIG. 5, the substrate 2a
On the front surface side, the cross sections are formed with a plurality of substantially trapezoidal portions 19 at intervals 18.

The insulating layer 3d is formed on the upper surface of the trapezoidal portion 19. The growth layer 5e is provided so as to cover the space 18 and the insulating layer 3d. The other layers are the same as the layers used in the optical semiconductor element 1. With the above structure, the growth layer 5e grows laterally on the insulating layer 3d, so that dislocations are reduced.

Next, an optical semiconductor device 20 according to the seventh embodiment of the present invention will be described with reference to the sectional views of FIGS. 6 and 7. In FIG. 6, a substrate 21 is obtained by dividing a wafer made of single crystal Si into a predetermined size. That is, the substrate 2
1 is made of a single crystal of Si. Although a substrate made of GaAs single crystal may be used, in the following description, the substrate is made of Si single crystal.

The insulating layer 22 is made of, for example, SiO ₂ .
A plurality of stripes are provided inside the substrate 21 so as to be aligned apart from each other with a gap 23.

The growth layer 24 is made of, for example, N-type GaN, has a substantially convex cross section, and has the gap 23 and the insulating layer 2.
It is provided on the substrate 21 so as to cover 2. The growth layer 24 is made of a Group III nitride compound.

The light emitting layer 25 is made of, for example, InGaN,
It is formed on the growth layer 24.

The cladding layer 26 is made of P-type GaAlN, for example, and is formed on the light emitting layer 25. The contact layer 27 is made of, for example, P-type GaAlN, and the cladding layer 2
It is formed on 6.

The P electrode 28 is made of gold or the like and is formed on the contact layer 27. Thus, the light emitting layer 25 is formed above the growth layer 24.

The N electrode 29 is formed on the growth layer 24,
It is formed on the surface where the position is low. By the above layers,
The optical semiconductor element 20 is configured.

In this optical semiconductor element 20, the movement of dislocations upward from the substrate 21 is blocked by the insulating layer 22. Therefore, the dislocations move only through the gap 23. As a result, the movement of dislocations from the substrate 21 to the growth layer 24 is significantly smaller than in the conventional case.

Further, depending on the applied voltage, the P electrode 28, the contact layer 27, the cladding layer 26, the light emitting layer 25, the growth layer 2
4. Since the current flows to the N electrode 29, there is no problem in the current path.

Next, an optical semiconductor element 30 according to the eighth embodiment of the present invention will be described with reference to FIGS. 6 and 7. In FIG. 6, the first matching layer 31 is formed so as to cover the gap 23 and the back surface of the insulating layer 22, is located on the substrate 21a, and is made of an Al single crystal.

The second matching layer 32 is located between the front surface of the gap 23 and the insulating layer 22 and the rear surface of the growth layer 24a, and G
It is composed of a single crystal of aAlN.

The other light emitting layer 25, cladding layer 26, contact layer 27, P electrode 28, and N electrode 29 are the same as the layers used in the optical semiconductor element 20. The optical semiconductor element 30 is composed of the above layers.

With respect to the first matching layer 31, triisobutyl is thermally vaporized on the substrate 21 by a bubbler by using a thermally activated CVD apparatus with argon as a carrier gas. Then, it is thermally activated by the GTC (gas temperature control unit).
After that, the activated substrate 21 is heated.
A single crystal of aluminum (first matching layer 31) is formed on a.

The lattice constant of Si forming the substrate 21a is 5.43 angstroms and the lattice constant of Al forming the first matching layer 31 is 4.05 angstroms, and the lattice mismatch rate is small.

On the other hand, the conventional optical semiconductor device 120
In this case, the lattice mismatch rate between the sapphire substrate 111 and the buffer layer 112 is large. As a result, the lattice mismatch rate between the substrate 21 and the first matching layer 31 of the present invention is about 1/2 that of the conventional one.

The movement of dislocations upward from the substrate 21a through the first matching layer 31 is blocked by the insulating layer 22. As a result, dislocations move only through the gap 23. As a result, the movement of dislocations from the substrate 21a to the growth layer 24a becomes about 3 × 10 ⁶ cm ⁻² , which is 10 ¹⁰
It is significantly smaller than cm ^-2 .

Next, an optical semiconductor element 33 according to the ninth embodiment of the present invention will be described with reference to the sectional view of FIG. In FIG. 8, the insulating layer 22 is formed in stripes inside the substrate 21a, aligned with each other with a gap 23 in between.

The thermal expansion coefficient of the insulating layer 22 (made of SiO ₂ ) of 0.5 × 10 ⁻⁶ / K and the thermal expansion coefficient of the substrate (made of GaAs single crystal) 21 a of 6 × 10 ⁻⁶ / K. The ratio between the width E of the gap 23 and the width F of the insulating layer 22 is determined so as to be inversely proportional to the ratio. That is, E: F = 6 × 10 ⁻⁶ / K:
0.5 × 10 ⁻⁶ / K = 12: 1 As described above, when the insulating layer 22 is formed inside the substrate 21a, the insulating layer 22 and the substrate 21a are
The proportions of the width E and the width F are determined in inverse proportion to the proportions of the respective thermal expansion coefficients. With this structure, the optical semiconductor element 33 is prevented from warping due to temperature rise.

Next, an optical semiconductor element 34 according to the tenth embodiment of the present invention will be described with reference to the sectional views of FIGS.

In these figures, a plurality of first mask layers 3
5 is a gap 23 so as to cover the gap 23 between the insulating layers 22.
And is formed in the growth layer 24a.

The first mask layer 35 is made of, for example, SiO ₂ . Desirably, the first mask layer 35 has a substantially trapezoidal cross section (see FIG. 10).

With the above structure, the dislocations that have moved from the substrate 21 through the gap 23 are blocked by the first mask layer 35. As a result, the dislocation density is reduced in the growth layer 24a.

The other layers are the same as the layers used in the optical semiconductor element 20.

Next, an optical semiconductor element 36 according to the eleventh embodiment of the present invention will be described with reference to the sectional view of FIG.

In FIG. 11, the first mask layer 35 (SiO 2
₂ )) so as to cover the gap 23 of the insulating layer 22,
It is located above the gap 23 and is formed in the growth layer 24b.

The plurality of second mask layers 37 (made of SiO ₂ etc.) are located above the openings 38 so as to cover at least the openings 38 of the first mask layers 35, and the growth layer 2 is formed.
It is provided in 4b. The second mask layer 37 desirably has a substantially trapezoidal cross section. The other layers are
It is the same as each layer used for the optical semiconductor element 34.

With the above structure, the dislocations that have moved from the substrate 21 through the gap 23 and through the opening 38 are blocked by the second mask layer 37. As a result, the dislocation density is reduced in the growth layer 24b.

Next, an optical semiconductor element 39 according to the twelfth embodiment of the present invention will be described with reference to the sectional view of FIG.

In FIG. 12, a substrate 40 is obtained by dividing a wafer made of single crystal Si doped with a first dopant (for example, phosphorus) into a predetermined size. That is, the substrate 40 is made of N-type Si to which the first dopant is added.

The plurality of insulating layers 41 are made of, for example, SiO 2 and are spaced apart from each other and aligned with each other.
It is provided on the 0 in a swipe shape.

The growth layer 43 is formed of a group III nitride compound (for example, N
Type GaN). The growth layer 43 is formed so as to cover the gap 42 and the insulating layer 41.

The light emitting layer 44 is made of, for example, InGaN,
It is formed on the growth layer 43.

The cladding layer 45 is made of, for example, P-type GaAlN and is formed on the light emitting layer 44. Like this
The light emitting layer 44 is formed above the growth layer 43.

The contact layer 46 is made of P-type GaN, for example, and is formed on the cladding layer 45.

The surface electrode 47 is made of gold, for example, and is formed on the contact layer 46. The back surface electrode 48 is made of, for example, gold and is formed on the back surface of the substrate 40. The optical semiconductor element 39 is composed of the above layers.

In this optical semiconductor element 39, the movement of dislocations upward from the substrate 40 is blocked by the insulating layer 41.

Therefore, dislocations move only through the gaps 42 between the insulating layers 41. As a result, the movement of dislocations from the substrate 40 to the growth layer 43 is about 3 × 10 ⁶ cm ^-2 , which is significantly smaller than the conventional 10 ¹⁰ cm ^-2 .

Further, the applied voltage causes a current to flow to the front surface electrode 47, the contact layer 46, the cladding layer 45, the light emitting layer 44, the growth layer 43, the gap 42, the substrate 40 and the back surface electrode 48. There is no.

Further, in this way, the surface electrode 47 is provided on the upper part,
Since the back surface electrode 48 is provided at the bottom, this optical semiconductor element 3
9 can be produced by conventional production equipment for light emitting diodes (GaP, GaAs, etc.).

Further, since the optical semiconductor element 39 has no step in the outer shape, the outer size of the element can be made smaller than that of the conventional light emitting diode (see FIG. 15) having the step.

Further, in the conventional light emitting diode (see FIG. 15), since both the P electrode 118 and the N electrode 119 are provided on the front surface side, it takes time and effort to connect with two wires.

On the other hand, in this optical semiconductor element 39, since the back electrode 48 is provided on the back surface of the substrate 40, the back electrode 48 can be die-bonded. As a result, it suffices to connect the surface electrode 47 with one wire, which facilitates the wiring work.

Next, an optical semiconductor element 49 according to the thirteenth embodiment of the present invention will be described with reference to the sectional view of FIG.

In FIG. 13, a wafer made of single-crystal GaAs doped with a second dopant (for example, phosphorus) is
The substrate 50 is divided into a predetermined size. That is, the substrate 50 is made of N-type GaA added with the second dopant.
s. The materials and configurations of the other layers are the same as those of the optical semiconductor element 39 shown in FIG.

Similar to the optical semiconductor element 39 shown in FIG. 12, in this optical semiconductor element 49, the movement of dislocations from the substrate 50 to the growth layer 43 is about 3 × 10 ⁶ cm ^-2 ,
It is significantly smaller than the conventional 10 ¹⁰ cm ^-2 .

Further, the applied voltage causes a current to flow to the front surface electrode 47, the contact layer 46, the cladding layer 45, the light emitting layer 44, the growth layer 43, the gap 42, the substrate 50 and the back surface electrode 48. Absent.

The optical semiconductor element 49 is similar to the optical semiconductor element 39 in that the conventional light emitting diodes (GaP, GaP) are used.
It can be produced by a production facility for As and the like.

Further, since the optical semiconductor element 49 has no step in the outer shape, the outer size of the element can be made smaller than that of the conventional light emitting diode having the step (see FIG. 15).

In the conventional light emitting diode (see FIG. 15), since both the P electrode 118 and the N electrode 119 are provided on the surface side, it takes time and effort to connect with two wires.

On the other hand, in this optical semiconductor element 49, since the back electrode 48 is provided on the back surface of the substrate 50, the back electrode 48 can be die-bonded. As a result, it suffices to connect the surface electrode 47 with one wire, which facilitates the wiring work.

Next, an optical semiconductor element 51 according to the fourteenth embodiment of the present invention will be described with reference to the sectional view of FIG. The substrate 2 is made of a single crystal of Si or a single crystal of GaAs.

The insulating layer 52 is made of, for example, SiO ₂ or the like,
It is formed on the entire surface of the substrate 2.

The Si layer 53 is made of, for example, a Si single crystal, and is spaced apart from each other with a gap 54, and is aligned with the insulating layer 52.
A plurality of stripes are provided on the top.

The growth layer 5f is made of, for example, N-type GaN,
It is provided so as to cover the gap 54 and the Si layer 53.

Other layers, that is, the light emitting layer 25, the cladding layer 26, the contact layer 27, the P electrode 28, and the N electrode 29.
Are the same as the layers of the optical semiconductor element 1 shown in FIG. 1, respectively. The optical semiconductor element 51 is composed of the above layers.

With the above structure, the dislocations in the substrate 2 tend to move upward, but the movement is blocked by the insulating layer 52.

[0101]

According to the first aspect of the present invention, a plurality of insulating layers, which are arranged in a stripe pattern on the substrate, are aligned with a substrate made of a single crystal of Si or a single crystal of GaAs with a gap therebetween. A layer, a growth layer formed so as to cover the gap and the insulating layer and made of a Group III nitride compound, and a light emitting layer provided above the growth layer. With the above structure, the movement of dislocations upward from the substrate is blocked by the insulating layer. As a result, the impurities collected at the dislocations hardly penetrate into the light emitting layer, so that the deterioration of the light output can be prevented.

According to a second aspect of the present invention, a first single crystal of Al is provided between the front surface of the substrate and the back surface of the insulating layer.
A matching layer is provided, and a second matching layer made of a GaAlN single crystal is provided so as to cover the gap and the insulating layer and is located below the growth layer. As described above, by providing the first matching layer made of Al single crystal on the substrate, the lattice mismatch rate is about 1/2 times that of the conventional one. Also, G
By providing the second matching layer made of a single crystal of aAlN, the second matching layer formed in the gap between the insulating layers easily grows in the lateral direction.

According to the third aspect of the present invention, the insulating layer has a substantially trapezoidal cross section. With this configuration, the ratio of the area occupied by the insulating layer on the substrate is reduced, and the lattice mismatch rate is reduced.

According to the present invention of claim 4, the front surface side of the substrate is formed into a plurality of substantially trapezoidal portions with cross sections spaced from each other.
The insulating layer is formed on the upper surface of the trapezoidal portion. With this configuration, the growth layer grows laterally on the insulating layer, so dislocations are reduced.

According to the present invention of claim 5, a plurality of insulating layers arranged in stripes inside the substrate are aligned with a substrate made of a single crystal of Si or a single crystal of GaAs with a gap therebetween. And a growth layer formed on the substrate and made of a Group III nitride compound, and a light emitting layer provided above the growth layer. Thus, by providing the insulating layer inside the substrate, the movement of dislocations upward from the substrate is further blocked by the insulating layer.

According to the sixth aspect of the present invention, a first matching layer made of Al single crystal is formed so as to cover the gap and the back surface of the insulating layer and is located on the substrate. A second matching layer made of GaAlN single crystal was provided between the front surface of the insulating layer and the back surface of the growth layer. Thus, by providing the first matching layer made of Al single crystal on the substrate, the lattice mismatch rate is about 1 of the conventional one.
/ 2 times. In addition, a second crystal composed of GaAlN single crystal
By providing the matching layer, the second matching layer formed in the gap between the insulating layers easily grows in the lateral direction.

According to the present invention of claim 7, the width of the gap and the width of the insulating layer are determined according to the ratio of the coefficient of thermal expansion of the growth layer or the insulating layer to the coefficient of thermal expansion of the substrate. The proportion was determined. Thus, by determining the ratio of the width of the gap and the width of the insulating layer according to the ratio of the coefficient of thermal expansion of each layer,
It is possible to prevent the optical semiconductor element from warping when the temperature rises.

According to the present invention of claim 8, a plurality of first mask layers are provided above the gap so as to cover the gap and provided in the growth layer. With the above structure, the dislocations moving in the gap are blocked by the first mask layer.

In the present invention of claim 9, the first mask layer is formed to have a substantially trapezoidal cross section. With the above structure, the effect of preventing the movement of dislocations is increased.

According to the tenth aspect of the present invention, at least the first mask layers are provided above the openings so as to cover the openings between the first mask layers and provided in the growth layer, and have a substantially trapezoidal cross section. A plurality of second mask layers was provided. With the above structure, dislocations moving in the opening of the first mask layer are blocked by the second mask layer.

According to the present invention of claim 11, Si doped with the first dopant or Ga doped with the second dopant is used.
A plurality of insulating layers arranged in a stripe pattern on the substrate and spaced apart from each other by a substrate made of As, and provided so as to cover the gap and the insulating layer;
A growth layer made of a Group III nitride compound and a light emitting layer provided above the growth layer were provided. Dislocations generated in the substrate made of Si doped with the first dopant or GaAs doped with the second dopant are prevented from moving by the insulating layer.

According to the twelfth aspect of the present invention, a back electrode is provided on the back surface of the substrate. With the above configuration, by providing the front surface electrode on the front surface and the back surface electrode on the back surface, it is possible to perform production by a normal production facility for light emitting diodes (GaP etc.).
Further, unlike the conventional case, since there is no step in the outer shape, the outer size of the element can be reduced. Further, by die-bonding the back surface electrode, it suffices to connect the front surface electrode with one wire, which facilitates the wiring work.

[Brief description of drawings]

FIG. 1 is a sectional view of an optical semiconductor device 1 according to a first embodiment of the present invention.

FIG. 2 is an optical semiconductor device 14 according to a third embodiment of the present invention.
FIG.

FIG. 3 is an optical semiconductor device 15 according to a fourth embodiment of the present invention.
FIG.

FIG. 4 is an optical semiconductor device 16 according to a fifth embodiment of the present invention.
FIG.

FIG. 5 is an optical semiconductor element 17 according to a sixth embodiment of the present invention.
FIG.

FIG. 6 is an optical semiconductor device 20 according to a seventh embodiment of the present invention.
FIG.

FIG. 7 is a cross-sectional view of an essential part of the optical semiconductor element 20.

FIG. 8 is an optical semiconductor device 33 according to a ninth embodiment of the present invention.
FIG.

FIG. 9 is an optical semiconductor element 3 according to Embodiment 10 of the present invention.
4 is a sectional view of FIG.

FIG. 10 is a cross-sectional view of an essential part of the optical semiconductor element 34.

FIG. 11 is a sectional view of an optical semiconductor element 36 according to an eleventh embodiment of the present invention.

FIG. 12 is a sectional view of an optical semiconductor element 39 according to a twelfth embodiment of the present invention.

FIG. 13 is a sectional view of an optical semiconductor element 49 according to a thirteenth embodiment of the present invention.

FIG. 14 is a sectional view of an optical semiconductor element 51 according to a fourteenth embodiment of the present invention.

FIG. 15 is a sectional view of a conventional optical semiconductor element 120.

[Explanation of symbols]

2 substrates 3 insulating layers 4 gap 5 Growth layer 6 light emitting layer 12 First matching layer 13 Second matching layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiromi Takasu             3-201 Minamiyoshikata, Tottori City, Tottori Prefecture Tottori             Sanyo Electric Co., Ltd. F-term (reference) 5F041 AA40 AA42 AA44 CA04 CA33                       CA34 CA35 CA40

Claims (12)

[Claims] 1. A plurality of insulating layers, which are arranged in a stripe pattern on the substrate, are aligned with a substrate made of a Si single crystal or a GaAs single crystal and are spaced apart from each other, and the gap and the insulation. An optical semiconductor device comprising: a growth layer formed so as to cover the layer and made of a Group III nitride compound; and a light emitting layer provided above the growth layer. 2. A first matching layer made of an Al single crystal is provided between the front surface of the substrate and the back surface of the insulating layer, and is formed so as to cover the gap and the insulating layer, and the growth layer. 2. The optical semiconductor device according to claim 1, further comprising a second matching layer which is located underneath and is made of a GaAlN single crystal. 3. The optical semiconductor element according to claim 1, wherein the insulating layer has a substantially trapezoidal cross section. 4. The surface side of the substrate is formed into a plurality of substantially trapezoidal portions with cross sections spaced apart, and the insulating layer is formed on an upper surface of the trapezoidal portion. Optical semiconductor device. 5. A substrate made of a single crystal of Si or a single crystal of GaAs, and a plurality of insulating layers arranged in a stripe shape inside the substrate, aligned with each other with a gap therebetween.
An optical semiconductor device comprising: a growth layer provided on the substrate, the growth layer being made of a Group III nitride compound; and a light emitting layer provided above the growth layer. 6. A first matching layer, which is formed so as to cover the gap and the back surface of the insulating layer and is located on the substrate and is made of an Al single crystal, and the gap and the surface of the insulating layer are provided. And the back surface of the growth layer, GaA
The optical semiconductor device according to claim 5, wherein a second matching layer made of 1N single crystal is provided. 7. The ratio between the width of the gap and the width of the insulating layer is determined according to the ratio of the coefficient of thermal expansion of the growth layer or the insulating layer and the coefficient of thermal expansion of the substrate. The optical semiconductor element according to claim 1 or 5, characterized in that 8. The method according to claim 1, further comprising a plurality of first mask layers which are located above the gap and are provided in the growth layer so as to cover the gap. Optical semiconductor device. 9. The optical semiconductor device according to claim 8, wherein the first mask layer has a substantially trapezoidal cross section. 10. A plurality of second mask layers located above the openings so as to cover at least the openings between the first mask layers, provided in the growth layer, and having a substantially trapezoidal cross section. The optical semiconductor device according to claim 8, further comprising: 11. A substrate comprising Si doped with a first dopant or GaAs doped with a second dopant;
A plurality of insulating layers arranged in a stripe shape on the substrate, spaced apart from each other and aligned with each other; and a growth layer formed of a Group III nitride compound and provided so as to cover the gaps and the insulating layer, An optical semiconductor device comprising a light emitting layer provided above the growth layer. 12. The optical semiconductor element according to claim 11, wherein a back electrode is provided on the back surface of the substrate.