JP2011119617A - Method of manufacturing rod type light emitting device - Google Patents

Abstract

Provided is a fine rod-shaped light emitting element having a high degree of freedom in mounting on an apparatus and high light extraction efficiency.
A step of forming a growth mask 12 having a growth hole 12a on a sapphire substrate 11, and a rod-like shape made of n-type GaN on an exposed region of the sapphire substrate 11 exposed by the growth hole 12a of the growth mask 12. A step of forming a semiconductor core, a semiconductor layer forming step of forming a semiconductor layer made of p-type GaN so as to cover a covered portion of the semiconductor core, and an exposed portion of the semiconductor core are exposed after the semiconductor layer forming step. A growth mask removing step for removing the growth mask 12 by etching, and a separation step for separating the semiconductor core including the exposed portion and the covering portion from the sapphire substrate 11 after the growth mask removing step. On the inner peripheral side of the growth hole 12a of the growth mask 12 and on the sapphire substrate 11 side, the narrowed portion 10 is formed so that the inner diameter becomes smaller toward the sapphire substrate 11 side.
[Selection] Figure 1-1

Description

  The present invention relates to a method for manufacturing a rod-shaped structure light emitting device.

  Conventionally, as a rod-shaped structure light emitting device, a flat first polar layer is formed on a substrate, and then a plurality of nano-order-sized rods corresponding to an active layer emitting light are formed on the first polar layer. Some form a second polar layer for wrapping (see, for example, Japanese Patent Laid-Open No. 2006-332650 (Patent Document 1)). In this rod-shaped structure light emitting element, light is emitted from a plurality of rods which are active layers.

  However, since the rod-shaped structure light emitting element is used in a state in which a plurality of rods are erected on a substrate, it is restricted by the substrate when incorporated in a lighting device or a display device. There is a problem that it is low. In addition, the rod-shaped structure light emitting device has a problem that the light extraction efficiency is lowered because most of the light is emitted sideways and absorbed by the adjacent rod.

JP 2006-332650 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a rod-shaped structure light-emitting element that can manufacture a fine rod-shaped structure light-emitting element that has a high degree of freedom in mounting on an apparatus and a high light extraction efficiency.

In order to solve the above problems, a method for manufacturing a rod-shaped structure light emitting device of the present invention includes:
A growth mask forming step of forming a growth mask having a growth hole for growing a rod-shaped first conductivity type semiconductor core inside on the substrate;
A semiconductor core forming step of forming the rod-shaped first conductivity type semiconductor core by crystal growth of the first conductivity type semiconductor on the exposed region of the substrate exposed by the growth hole of the growth mask;
A semiconductor layer forming step of forming a second conductivity type semiconductor layer so as to cover a covering portion which is a part of the semiconductor core;
A growth mask removing step of removing the growth mask by etching so as to expose an exposed portion which is another part of the semiconductor core after the semiconductor layer forming step;
A separation step of separating the semiconductor core including at least a part of the exposed portion and the covering portion from the substrate after the growth mask removing step;
In the growth mask forming step, a shape changing portion in which the shape of a cross section perpendicular to the axial direction of the growth hole is changed along the axial direction is formed on the inner peripheral side of the growth hole of the growth mask. A growth mask is formed.

  According to the above configuration, after the growth mask having the growth hole is formed on the substrate, the first conductivity type semiconductor is crystal-grown on the exposed region of the substrate exposed by the growth hole of the growth mask, thereby forming the rod-like shape. A semiconductor core of the first conductivity type is formed. Thereafter, a second conductivity type semiconductor layer is formed so as to cover the covering portion which is a part of the semiconductor core. Next, after removing the growth mask by etching so as to expose the exposed part which is the other part of the semiconductor core, the semiconductor core including at least a part of the exposed part and the covering part is formed on the substrate by, for example, ultrasonic waves. Separate from the substrate by vibrating or using a cutting tool. The rod-shaped structure light-emitting element thus separated from the substrate has one electrode connected to the exposed portion of the semiconductor core, the other electrode connected to the semiconductor layer, and the outer peripheral surface of the semiconductor core and the inside of the semiconductor layer. Light is emitted from the pn junction by flowing current between the electrodes so that recombination of electrons and holes occurs at the pn junction with the peripheral surface.

  Further, in the growth mask forming step, by providing a shape changing portion in which the shape of the cross section perpendicular to the axial direction of the growth hole is changed along the axial direction on the inner peripheral side of the growth hole of the growth mask, the semiconductor The cross-sectional shape orthogonal to the axial direction of the exposed portion of the core can be changed to an arbitrary shape, and the degree of freedom in design is increased. For example, the exposed portion of the semiconductor core can be provided with a separation part (diaphragm) and a cutting part (groove, etc.) from the substrate, and it becomes easy to separate the rod-shaped structure light emitting element from the substrate, and the rod-shaped structure light emitting element. Variation in length can be reduced.

  In this way, it is possible to manufacture a fine rod-shaped structure light-emitting element having a high degree of freedom for mounting on the device and a high light extraction efficiency. Here, the fine rod-shaped structure light emitting element is, for example, an element having a diameter of 10 nm to 5 μm and a length of 100 nm to 200 μm, more preferably a diameter of 100 nm to 2 μm and a length of 1 μm to 50 μm. In addition, the rod-shaped structure light emitting element can reduce the amount of semiconductor used, can reduce the thickness and weight of the device using the light emitting element, and can emit light from the entire circumference of the semiconductor core covered with the semiconductor layer. Since the emission region is widened by being emitted, a light-emitting device, a backlight, a lighting device, a display device, and the like with high emission efficiency and power saving can be realized.

In addition, a method for manufacturing a rod-shaped structure light emitting device of an embodiment is as follows:
In the semiconductor core forming step, the first conductivity type semiconductor is crystal-grown on the exposed region of the substrate exposed by the growth hole of the growth mask so as to exceed the height of the growth hole of the growth mask. Forming a semiconductor core,
In the semiconductor layer forming step, the semiconductor layer is formed so as to cover the covered portion of the semiconductor core formed and exposed above the growth mask surface.

  According to the embodiment, after the growth mask having the growth hole is formed on the substrate, the growth mask is so formed as to exceed the height of the growth hole of the growth mask on the exposed region of the substrate exposed by the growth hole of the growth mask. A rod-shaped first-conductivity-type semiconductor core is formed by crystal growth of a one-conductivity-type semiconductor. Thereafter, a semiconductor layer of the second conductivity type is formed so as to cover the exposed coating portion of the semiconductor core formed above the growth mask surface. In the semiconductor core forming step, the surface shape of the semiconductor core on the substrate side can be easily controlled by the shape changing portion provided on the inner peripheral side of the growth hole of the growth mask.

In addition, a method for manufacturing a rod-shaped structure light emitting device of an embodiment is as follows:
In the semiconductor core formation step, the semiconductor core is formed by crystal growth of a first conductivity type semiconductor on the exposed region of the substrate exposed by the growth hole of the growth mask and in the growth hole of the growth mask,
After the semiconductor core forming step and before the semiconductor layer forming step, an upper portion of the growth mask is removed by etching, and an exposing step is performed to expose the covering portion of the semiconductor core,
In the semiconductor layer forming step, the semiconductor layer is formed so as to cover the covered portion of the semiconductor core exposed in the exposing step.

  According to the embodiment, after the growth mask having the growth hole is formed on the substrate, the first conductivity type semiconductor is formed on the exposed region of the substrate exposed by the growth hole of the growth mask and in the growth hole of the growth mask. By growing the crystal, a rod-shaped first conductive type semiconductor core is formed. Thereafter, the upper part of the growth mask is removed by etching, a part of the semiconductor core is exposed, and a semiconductor layer of the second conductivity type is formed so as to cover the exposed part of the semiconductor core. As described above, since all of the semiconductor core is formed in the growth hole of the growth mask, it is possible to easily control the shape of the entire semiconductor core using the shape change portion of the growth mask.

Moreover, in the manufacturing method of the rod-shaped structure light emitting device of one embodiment,
The substrate includes a substrate body and a first conductivity type semiconductor film on the substrate body,
In the growth mask formation step, a growth mask having the growth holes is formed on the semiconductor film of the substrate.

  According to the embodiment, after forming the growth mask having the growth hole on the semiconductor film formed on the substrate, the first conductivity type is formed on the exposed region of the semiconductor film exposed by the growth hole of the growth mask. A rod-shaped first-conductivity-type semiconductor core is formed by crystal growth of the semiconductor. Thereby, a semiconductor core with few crystal defects can be formed.

Moreover, in the manufacturing method of the rod-shaped structure light emitting device of one embodiment,
A quantum well layer forming step of forming a quantum well layer so as to cover the surface of the semiconductor core after the semiconductor core forming step and before the semiconductor layer forming step;
In the next semiconductor core formation step, the semiconductor layer is formed so as to cover the surface of the quantum well layer.

  According to the embodiment, by forming the quantum well layer between the semiconductor core and the semiconductor layer, the light emission efficiency can be improved by the quantum confinement effect of the quantum well layer.

Moreover, in the manufacturing method of the rod-shaped structure light emitting device of one embodiment,
The shape change portion of the growth mask is an aperture portion formed on the inner peripheral side and substrate side of the growth hole so that the inner diameter decreases toward the substrate side, or the inner peripheral side of the growth hole And a constricted portion formed so as to be constricted at a position spaced apart from the substrate side by a predetermined interval.

  According to the above embodiment, in the growth mask forming step, by the aperture portion as the shape changing portion provided on the inner peripheral side of the growth hole of the growth mask and on the substrate side so that the inner diameter becomes smaller toward the substrate side. Since the end of the semiconductor core on the substrate side is tapered, the semiconductor core can be easily separated from the substrate in the separation step, and variations in the length of the rod-shaped structure light emitting element can be reduced. Alternatively, in the growth mask forming step, an annular groove portion is formed in the semiconductor core by a constricted portion as a shape changing portion provided so as to be constricted at a position spaced from the inner peripheral side of the growth hole of the growth mask and from the substrate side. Since it is formed, the semiconductor core can be easily separated by the annular groove portion in the separation step, and variations in the length of the rod-shaped structure light emitting element can be reduced.

Moreover, in the manufacturing method of the rod-shaped structure light emitting device of one embodiment,
A catalyst metal layer forming step for forming a catalyst metal layer on the exposed region of the substrate exposed by the growth hole of the growth mask after the growth mask forming step and before the semiconductor core forming step;
In the next semiconductor core forming step, the semiconductor core is formed by crystal growth of the first conductivity type semiconductor from the interface between the catalytic metal layer and the substrate.

  According to the embodiment, after forming the catalytic metal layer on the exposed region of the substrate exposed by the growth hole of the growth mask after the growth mask forming step and before the semiconductor core forming step, the catalytic metal layer is formed. A semiconductor core with few crystal defects is formed by forming a rod-shaped first conductivity type semiconductor core on the formed substrate by crystal growth of the first conductivity type semiconductor from the interface between the catalytic metal layer and the substrate. it can. Therefore, it is possible to realize a rod-shaped structure light emitting device with good characteristics.

  Further, after the semiconductor core forming step, the surface of the semiconductor core is grown by crystal growth from the outer peripheral surface of the semiconductor core and the interface between the catalytic metal layer and the tip of the semiconductor core with the catalyst metal layer held at the tip of the semiconductor core. By forming the semiconductor layer of the second conductivity type covering the semiconductor layer, crystal growth from the interface between the catalytic metal layer and the semiconductor core is promoted more than the outer peripheral surface of the semiconductor core. The thickness in the axial direction of the portion covering the end face on the other end side of the semiconductor core can be made larger than the thickness in the radial direction of the portion covering the semiconductor core.

  As is apparent from the above, according to the method for manufacturing a rod-shaped structure light emitting device of the present invention, it is possible to realize a fine rod-shaped structure light emitting device having a high degree of freedom for mounting on a device and a high light extraction efficiency.

FIGS. 1-1 is process drawing of the manufacturing method of the rod-shaped structure light emitting element of 1st Embodiment of this invention. FIGS. FIGS. 1-2 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 1-1. 1-3 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 1-2. FIG. 1-4 is a process diagram of the manufacturing method of the rod-shaped structure light emitting element following FIG. 1-3. FIG. 2-1 is a cross-sectional view of a main part of a growth mask used in the method for manufacturing the rod-shaped structure light emitting device of the first embodiment. FIG. 2B is a cross-sectional view of the tip of a semiconductor core formed using the growth mask of FIG. FIG. 3A is a cross-sectional view of a modified example of the growth mask used in the method for manufacturing a rod-shaped structure light emitting device. FIG. 3B is a cross-sectional view of the front end portion of the semiconductor core formed using the growth mask of FIG. FIG. 4A is a cross-sectional view of a modified example of the growth mask used in the method for manufacturing the rod-shaped structure light emitting device. FIG. 4B is a cross-sectional view of the front end portion of the semiconductor core formed using the growth mask of FIG. FIGS. 5-1 is process drawing of the manufacturing method of the rod-shaped structure light emitting element of 2nd Embodiment of this invention. FIG. 5-2 is a process diagram of the manufacturing method of the rod-shaped structure light emitting element subsequent to FIG. 5-1. FIGS. 5-3 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 5-2. FIGS. 5-4 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 5-3. FIGS. 6-1 is process drawing of the manufacturing method of the rod-shaped structure light emitting element of 3rd Embodiment of this invention. FIG. 6B is a process diagram of the manufacturing method of the rod-shaped structure light emitting element following FIG. 6A. FIG. 6-3 is a process diagram of the manufacturing method of the rod-shaped structure light emitting element following FIG. 6-2. FIG. 6-4 is a process diagram of the method for manufacturing the rod-shaped structure light emitting element, following FIG. 6-3. FIGS. 6-5 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 6-4. 6-6 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 6-5. FIGS. 7-1 is process drawing of the manufacturing method of the rod-shaped structure light emitting element of 4th Embodiment of this invention. FIG. 7-2 is a process diagram of the manufacturing method of the rod-shaped structure light emitting element continued from FIG. FIG. 7C is a process diagram of the manufacturing method of the rod-shaped structure light emitting element continued from FIG. FIG. 7-4 is a process diagram of the manufacturing method of the rod-shaped structure light emitting device continued from FIG. FIGS. 8-1 is process drawing of the manufacturing method of the rod-shaped structure light emitting element of 5th Embodiment of this invention. FIGS. FIGS. 8-2 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 8-1. FIGS. 8-3 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 8-2. FIGS. 8-4 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 8-3. FIG. 8-5 is a process diagram of the method for manufacturing the rod-shaped structure light emitting device, following FIG. 8-4. FIG. 8-6 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element subsequent to FIG. 8-5. FIGS. 8-7 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 8-6. FIG. 8-8 is a process diagram of the method for manufacturing the rod-shaped structure light emitting device, following FIG. 8-7. FIGS. 8-9 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 8-8. FIGS. 8-10 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 8-9. FIGS. 8-11 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 8-10. 8-12 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element subsequent to FIG. 8-11. FIGS. 8-13 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 8-12. FIGS. 8-14 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 8-13. FIGS. 8-15 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 8-14. FIG. 9 is a side view of the rod-shaped structure light emitting device of the fifth embodiment. FIGS. 10-1 is process drawing of the manufacturing method of the rod-shaped structure light emitting element of 6th Embodiment of this invention. FIG. 10-2 is a process diagram of the manufacturing method of the rod-shaped structure light emitting element continued from FIG. FIG. 10-3 is a process diagram of the method for manufacturing the rod-shaped structure light emitting device, following FIG. 10-2. FIG. 10-4 is a process diagram of the manufacturing method of the rod-shaped structure light emitting element continued from FIG. FIG. 10-5 is a process diagram of the method for manufacturing the rod-shaped structure light emitting device, following FIG. 10-4. FIG. 10-6 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element subsequent to FIG. 10-5. FIG. 10-7 is a process diagram of the method for manufacturing the rod-shaped structure light emitting device, following FIG. 10-6. FIG. 10-8 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element subsequent to FIG. 10-7. FIG. 10-9 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element subsequent to FIG. 10-10 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element subsequent to FIG. 10-9. FIG. 10-11 is a process diagram of the manufacturing method of the rod-shaped structure light emitting device subsequent to FIG. 10-10. 10-12 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element subsequent to FIG. 10-11. 10-13 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 10-12. FIG. 11A is a process diagram of a method for manufacturing a rod-shaped structure light emitting element according to the seventh embodiment of the present invention. FIG. 11-2 is a process diagram of the manufacturing method of the rod-shaped structure light emitting element continued from FIG. FIG. 11C is a process diagram of the manufacturing method of the rod-shaped structure light emitting element continued from FIG. FIG. 11-4 is a process diagram of the manufacturing method of the rod-shaped structure light emitting element continued from FIG. 11-3. FIG. 11-5 is a process diagram of the method for manufacturing the rod-shaped structure light-emitting element continued from FIG. 11-4. FIG. 11-6 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element subsequent to FIG. 11-5. FIG. 11-7 is a process drawing of the method for manufacturing the rod-shaped structure light emitting device, following FIG. 11-6. FIG. 11-8 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element subsequent to FIG. 11-7. FIG. 11-9 is a process drawing of the method for manufacturing the rod-shaped structure light emitting device, following FIG. 11-8. FIG. 11-10 is a process drawing of the method for manufacturing the rod-shaped structure light emitting device, following FIG. 11-9. FIG. 11-11 is a process diagram of the manufacturing method of the rod-shaped structure light emitting element subsequent to FIG. 11-10. 11-12 is a process drawing of the manufacturing method of the rod-shaped structure light-emitting element following FIG. 11-11. 11-13 is a process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 11-12. FIGS. 11-14 is process drawing of the manufacturing method of the rod-shaped structure light emitting element following FIG. 11-13. FIG. 12-1 is a process diagram of a method for manufacturing a rod-shaped structure light emitting element according to the eighth embodiment of the present invention. FIG. 12-2 is a process diagram of the manufacturing method of the rod-shaped structure light emitting element continued from FIG. FIG. 12-3 is a process diagram of the manufacturing method of the rod-shaped structure light emitting element subsequent to FIG. 12-2. FIG. 12D is a process diagram of the method for manufacturing the rod-shaped structure light emitting element, following FIG. FIG. 12-5 is a process diagram of the method for manufacturing the rod-shaped structure light-emitting element continued from FIG. 12-4. 12-6 is a process drawing of the manufacturing method of the rod-shaped structure light-emitting element following FIG. 12-5. 12-7 is a process drawing of the manufacturing method of the rod-shaped structure light-emitting element following FIG. 12-6. FIG. 13 is a plan view of an insulating substrate used in a light emitting device, a backlight, a lighting device, and a display device including a bar-shaped light emitting element according to the ninth embodiment of the present invention. FIG. 14 is a schematic sectional view taken along line XIV-XIV in FIG. FIG. 15 is a diagram for explaining the principle of arranging the rod-shaped structure light emitting elements. FIG. 16 is a diagram for explaining the potential applied to the electrodes when the rod-shaped structure light emitting elements are arranged. FIG. 17 is a plan view of an insulating substrate on which the rod-shaped structure light emitting elements are arranged. FIG. 18 is a plan view of the display device. FIG. 19 is a circuit diagram of a main part of the display unit of the display device.

  Hereinafter, the manufacturing method of the rod-shaped structure light emitting element of this invention is demonstrated in detail by embodiment of illustration. In this embodiment, the first conductivity type is n-type and the second conductivity type is p-type. However, the first conductivity type may be p-type and the second conductivity type may be n-type. In this embodiment, n-type GaN doped with Si and p-type GaN doped with Mg are used. However, impurities doped in GaN are not limited thereto.

[First Embodiment]
FIGS. 1-1 to 1-4 show process drawings of the method of manufacturing the rod-shaped structure light emitting device according to the first embodiment of the present invention.

First, as shown in FIG. 1A, a growth mask 12 having a growth hole 12a is formed on a sapphire substrate 11 in a growth mask formation step. For the growth mask, a material that can be selectively etched with respect to the semiconductor core and the semiconductor layer, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), can be used. The growth hole 12a can be formed by a known lithography method and dry etching method used in a normal semiconductor process. At this time, the diameter of the growing semiconductor core depends on the size of the growth hole of the growth mask.

  In this growth mask formation step, a diaphragm as an example of a shape changing portion in which the shape of the cross section perpendicular to the axial direction of the growth hole 12a is changed along the axial direction on the inner peripheral side of the growth hole 12a of the growth mask 12. Part 10 is provided. The narrowed portion 10 is formed on the sapphire substrate 11 side of the growth hole 12a of the growth mask 12 so that the inner diameter becomes smaller toward the sapphire substrate 11 side, and an exposed region of the sapphire substrate 11 in the growth hole 12a is formed. The growth hole 12a is smaller than the cross section perpendicular to the axial direction of the portion other than the narrowed portion 10.

Next, as shown in FIG. 1-2, MOCVD (Metal Organic Chemical Vapor Deposition) is formed on the exposed region of the sapphire substrate 11 exposed by the growth hole 12a of the growth mask 12 in the semiconductor core forming step. The rod-shaped semiconductor core 13 having a substantially circular cross section is formed by crystal growth of n-type GaN using an apparatus. The growth temperature is set to about 800 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for supplying n-type impurities, and hydrogen (H ₂ ) is used as a carrier gas. , An n-type GaN semiconductor core having Si as an impurity can be grown.

Next, in the semiconductor layer forming step, the semiconductor layer 14 made of p-type GaN is formed on the entire surface of the sapphire substrate 11 so as to cover the covering portion 13b (shown in FIG. 1-3) of the rod-shaped semiconductor core 13. The formation temperature is set to about 900 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, and biscyclopentadienylmagnesium (Cp ₂ Mg) is used for supplying p-type impurities. P-type GaN with impurities as a dopant can be grown.

Next, as shown in FIG. 1C, in the growth mask removal step, the region excluding the portion of the semiconductor layer 14 covering the semiconductor core 13 and the growth mask 12 are removed by lift-off to remove the sapphire substrate of the rod-shaped semiconductor core 13. The exposed portion 13a is formed by exposing the outer peripheral surface on the 11th side. In this state, the tip portion 13c on the sapphire substrate 11 side of the exposed portion 13a of the semiconductor core 13 has a tapered shape. The end face of the semiconductor core 13 opposite to the sapphire substrate 11 is covered with a semiconductor layer 14a. When the growth mask is composed of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), a semiconductor layer and a semiconductor layer that easily covers the semiconductor core can be obtained by using a solution containing hydrofluoric acid (HF). The growth mask can be etched without affecting the portion, and the region excluding the portion of the semiconductor layer covering the semiconductor core together with the growth mask can be removed by lift-off. In the growth mask removing process of this embodiment, lift-off is used, but a part of the semiconductor core may be exposed by etching. In the case of dry etching, by using CF ₄ or XeF ₂ , the growth mask can be easily etched without affecting the semiconductor core and the semiconductor layer portion covering the semiconductor core, and the semiconductor covering the semiconductor core together with the growth mask. Regions other than the layer portions can be removed.

  Next, in the separation step, the substrate is immersed in an aqueous solution of isopropyl alcohol (IPA), and the sapphire substrate 11 is vibrated along the substrate plane using ultrasonic waves (for example, several tens of kHz), whereby the tip portion 13c of the semiconductor core 13 is obtained. A stress acts on the semiconductor core 13 covered with the semiconductor layer 14a so that the semiconductor core 13 covered with the semiconductor layer 14a is bent as shown in FIG. It is separated from the sapphire substrate 11. As a result, a rod-shaped structure light emitting element including the rod-shaped semiconductor core 13 having the exposed portion 13a on one end side and the semiconductor layer 14a covering the coating portion 13b other than the exposed portion 13a of the semiconductor core 13 is obtained.

  In this way, a fine rod-shaped structure light-emitting element separated from the sapphire substrate 11 can be manufactured. In the first embodiment, the diameter of the rod-shaped structure light-emitting element is 1 μm and the length is 10 μm (in FIGS. 1-1 to 1-4, the length of the rod-shaped structure light-emitting element is drawn short for easy understanding of the drawings. )

  1A to 1D show one bar-shaped light emitting element, a plurality of bar-shaped light emitting elements are provided on the sapphire substrate 11.

  In this rod-shaped structure light emitting element, one electrode is connected to the exposed portion 13 a of the semiconductor core 13, the other electrode is connected to the semiconductor layer 14 a, and current is supplied from the p-type semiconductor layer 14 a to the n-type semiconductor core 13. By flowing, electrons and holes are recombined at the pn junction between the outer peripheral surface of the n-type semiconductor core 13 and the inner peripheral surface of the p-type semiconductor layer 14a, and light is emitted. Since light is emitted from the entire circumference of the semiconductor core 13 covered with the semiconductor layer 14a, the light emitting region is widened, so that high light emission efficiency is obtained.

  According to the method for manufacturing a bar-shaped light emitting element having the above-described configuration, a fine bar-shaped light emitting element having a high degree of freedom in mounting on a device and a high light extraction efficiency can be manufactured. Further, since the rod-shaped structure light emitting element is used as a fine structure separated from the sapphire substrate 11, the amount of semiconductor to be used can be reduced, and the device using the light emitting element can be made thinner and lighter, Since light is emitted from the entire circumference of the semiconductor core 13 covered with the semiconductor layer 14a, the light emitting region is widened, so that a light emitting device, a backlight, a lighting device, a display device, and the like with high light emission efficiency are realized. be able to.

  Further, in the growth mask removing step of exposing a part of the outer peripheral surface of the semiconductor core 13, the outer peripheral surface of the semiconductor core 13 on the sapphire substrate 11 side is exposed, and in the semiconductor layer forming step, the sapphire substrate 11 of the semiconductor core 13. By covering the end face on the opposite side with the semiconductor layer 14, the exposed portion 13a of the semiconductor core 13 on the sapphire substrate 11 side is connected to the n-side electrode, and the end face on the opposite side of the semiconductor core 13 to the sapphire substrate 11 is the semiconductor layer. By being covered with 14a, the p-side electrode can be connected to the portion of the semiconductor layer 14a that covers the side of the semiconductor core 13 opposite to the sapphire substrate 11. This makes it possible to easily connect the electrodes to both ends of the fine rod-shaped structure light emitting element.

  Further, in the separation step, the interface between the tip portion 13c of the semiconductor core 13 standing on the sapphire substrate 11 and the sapphire substrate 11 is obtained by vibrating the sapphire substrate 11 along the plane of the sapphire substrate 11 using ultrasonic waves. As shown in FIG. 2, stress is applied to the semiconductor core 13 covered with the semiconductor layer 14a, and the semiconductor core 13 covered with the semiconductor layer 14a is separated from the sapphire substrate 11. Therefore, a plurality of fine rod-shaped light emitting elements provided on the sapphire substrate 11 can be easily separated by a simple method.

  In the separation step, the semiconductor core 13 may be mechanically separated from the sapphire substrate 11 using a cutting tool. A cutting tool is used to bend at the interface between the tip 13c of the semiconductor core 13 standing on the sapphire substrate 11 and the sapphire substrate 11, and stress is applied to the semiconductor core 13 covered with the semiconductor layer 14a. The semiconductor core 13 covered with the semiconductor layer 14 a is separated from the sapphire substrate 11. In this case, a plurality of fine rod-shaped structure light emitting elements provided on the sapphire substrate 11 can be separated in a short time by a simple method.

  Further, dry etching may be used in the growth mask removing step, and a part of the outer peripheral surface of the semiconductor core 13 made of a semiconductor having GaN as a base material can be easily exposed. Since a semiconductor using GaN as a base material is difficult to perform wet etching, the semiconductor core 13 covered with the semiconductor layer 14a is separated from the sapphire substrate 11 without a growth mask removing step that exposes a part of the outer peripheral surface of the semiconductor core 13. In the case of manufacturing a fine rod-shaped structure light emitting device, after arranging the fine rod-shaped structure light emitting device on an insulating substrate, a part of the outer peripheral surface of the semiconductor core 13 is exposed for electrode connection using wet etching. I can't. Therefore, when the semiconductor core 13 and the semiconductor layer 14a are made of a semiconductor having GaN as a base material, exposing a part of the outer peripheral surface of the semiconductor core 13 by dry etching in advance before the separation process is easy to mount. This is particularly effective in realizing a simple rod-shaped structure light emitting device.

  Furthermore, in the rod-shaped structure light-emitting device manufactured by the method for manufacturing the rod-shaped structure light-emitting device, the semiconductor layer 14a grows radially outward from the outer peripheral surface of the semiconductor core 13, the radial growth distance is short, and the defects are outward. Therefore, the semiconductor core 13 can be covered with the semiconductor layer 14a with few crystal defects. Therefore, it is possible to realize a rod-shaped structure light emitting device with good characteristics.

  In the manufacturing method of the rod-shaped structure light emitting device, after the growth mask 12 having the growth hole 12a is formed on the sapphire substrate 11, the growth mask is formed on the exposed region of the sapphire substrate 11 exposed by the growth hole 12a of the growth mask 12. After the rod-shaped semiconductor core 13 is formed by crystal growth of n-type GaN so as to exceed the height of the 12 growth holes 12a, the covered portion of the semiconductor core 13 that is formed and exposed above the surface of the growth mask 12 is exposed. The semiconductor layer 14a is formed so as to cover. Thereby, in the semiconductor core forming step, the surface shape of the semiconductor core 13 on the sapphire substrate 11 side can be controlled by the narrowed portion 10 as the shape changing portion provided on the inner peripheral side of the growth hole 12a of the growth mask 12. Easy to do.

  Further, in the growth mask forming step, a narrowing portion as a shape change portion provided on the inner peripheral side of the growth hole 12a of the growth mask 12 and on the sapphire substrate 11 side so that the inner diameter becomes smaller toward the sapphire substrate 11 side. 10, the end of the semiconductor core 13 on the sapphire substrate 11 side is tapered, so that the semiconductor core 13 can be easily separated from the sapphire substrate 11 in the separation step. Can be reduced.

  In the first embodiment, the narrowed portion 10 is formed as the shape changing portion on the inner peripheral side of the growth hole 12a of the growth mask 12, but the shape of the cross section orthogonal to the axial direction of the growth hole is in the axial direction. You may provide the other shape change part which changed along.

  2A is a cross-sectional view of the main part of the growth mask 12 used in the method for manufacturing the rod-shaped structure light emitting device of the first embodiment, and FIG. 2B is formed using the growth mask 12 of FIG. 2 is a cross-sectional view of the tip of the semiconductor core 13.

  In the first embodiment, after the growth mask 12 is formed on the sapphire substrate 11, the growth hole is formed in the vicinity of the sapphire substrate 11 using the resist pattern on the growth mask 12. Thereafter, the growth hole is widened by wet etching to form the growth hole 12a and the narrowed portion 10 (shape changing portion) shown in FIG.

  In addition, the shape and the formation method of the narrowed portion of the growth hole of the growth mask are not limited to this, and any narrowed portion formed so that the inner diameter becomes smaller toward the substrate side may be used.

  For example, as shown in FIG. 3A, a plurality of growth masks are stacked on a sapphire substrate 21 to form a growth mask 22, thereby forming a narrowed portion 20 that expands stepwise toward the sapphire substrate 11 side of the growth hole 22 a. May be formed. FIG. 3-2 shows a cross section of the tip 23c of the semiconductor core 23 formed using the growth mask 22 of FIG. 3-1. As shown in FIG. 3B, the tip 23c of the semiconductor core 23 has a stepped shape.

  Further, as shown in FIG. 4A, after forming the growth mask 32 on the sapphire substrate 31, a growth hole is formed up to the vicinity of the sapphire substrate 31 using a resist pattern on the growth mask 32, and then a corrosive gas or the like is used. The growth hole may be widened to form the growth hole 32a and the narrowed portion 30 (shape changing portion) shown in FIG. FIG. 4B shows a cross section of the tip 33c of the semiconductor core 33 formed using the growth mask 32 of FIG. 4-1. As shown in FIG. 4B, the tip 33c of the semiconductor core 33 has a tapered shape with a barbed surface.

  In the first embodiment, the growth mask 12 having the growth holes 12a is formed on the sapphire substrate 11 and the semiconductor core 13 is crystal-grown in the growth holes 12a. However, the substrate is not limited to this, for example, n A substrate made of GaN may be used, or a substrate in which a semiconductor film made of n-type GaN is formed on a sapphire substrate may be used.

[Second Embodiment]
5-1 to 5-4 show process drawings of the method for manufacturing the rod-shaped structure light emitting device according to the second embodiment of the present invention. The manufacturing method of the rod-shaped structure light emitting element of the second embodiment has the same steps as the manufacturing method of the rod-shaped structure light emitting element of the first embodiment except for the semiconductor film.

First, as shown in FIG. 5A, in the semiconductor film formation process, a semiconductor film 45 made of n-type GaN is formed on a sapphire substrate 41 as an example of a substrate body using an MOCVD apparatus, and then grown. In the mask formation step, a growth mask 42 having a growth hole 42 a is formed on the semiconductor film 45. For the growth mask, a material that can be selectively etched with respect to the semiconductor core and the semiconductor layer, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), can be used. The growth hole 42a can be formed by a known lithography method and dry etching method used in a normal semiconductor process. At this time, the diameter of the growing semiconductor core depends on the size of the growth hole of the growth mask.

  In this growth mask forming step, a diaphragm as an example of a shape change portion in which the shape of the cross section orthogonal to the axial direction of the growth hole 42a is changed along the axial direction on the inner peripheral side of the growth hole 42a of the growth mask 42. A portion 40 is provided. The narrowed portion 40 is formed on the semiconductor film 45 side of the growth hole 42a of the growth mask 42 so that the inner diameter becomes smaller toward the semiconductor film 45 side, and the exposed region of the semiconductor film 45 in the growth hole 42a is formed. The growth hole 42a is smaller than the cross section perpendicular to the axial direction of the portion other than the narrowed portion 40.

Next, as shown in FIG. 5B, in the semiconductor core formation step, n-type GaN is grown on the exposed region of the semiconductor film 45 exposed by the growth hole 42a of the growth mask 42 using an MOCVD apparatus. As a result, a rod-shaped semiconductor core 43 having a substantially circular cross section is formed. The growth temperature is set to about 800 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for supplying n-type impurities, and hydrogen (H ₂ ) is used as a carrier gas. , An n-type GaN semiconductor core having Si as an impurity can be grown.

Next, in the semiconductor layer forming step, the semiconductor layer 44 made of p-type GaN is formed on the entire surface of the sapphire substrate 41 so as to cover the covering portion 43b (shown in FIG. 5-3) of the rod-shaped semiconductor core 43. The formation temperature is set to about 900 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, and biscyclopentadienylmagnesium (Cp ₂ Mg) is used for supplying p-type impurities. P-type GaN with impurities as a dopant can be grown.

Next, as shown in FIG. 5C, in the growth mask removing step, the region excluding the portion of the semiconductor layer 44 covering the semiconductor core 43 and the growth mask 42 are removed by lift-off to remove the sapphire substrate of the rod-shaped semiconductor core 43. The exposed portion 43a is formed by exposing the outer peripheral surface on the 41 side. In this state, the tip portion 43c on the sapphire substrate 41 side of the exposed portion 43a of the semiconductor core 43 has a tapered shape. The end surface of the semiconductor core 43 opposite to the sapphire substrate 41 is covered with a semiconductor layer 44a. When the growth mask is composed of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), a semiconductor layer and a semiconductor layer that easily covers the semiconductor core can be obtained by using a solution containing hydrofluoric acid (HF). The growth mask can be etched without affecting the portion, and the region excluding the portion of the semiconductor layer covering the semiconductor core together with the growth mask can be removed by lift-off. In the growth mask removing process of this embodiment, lift-off is used, but a part of the semiconductor core may be exposed by etching. In the case of dry etching, by using CF ₄ or XeF ₂ , the growth mask can be easily etched without affecting the semiconductor core and the semiconductor layer portion covering the semiconductor core, and the semiconductor covering the semiconductor core together with the growth mask. Regions other than the layer portions can be removed.

  Next, in the separation step, the substrate is immersed in an aqueous solution of isopropyl alcohol (IPA), and the sapphire substrate 41 is vibrated along the substrate plane using ultrasonic waves (for example, several tens of kHz), whereby the tip portion 43c of the semiconductor core 43 is obtained. Stress is applied to the semiconductor core 43 covered with the semiconductor layer 44a so that the semiconductor core 43 covered with the semiconductor layer 44a is bent as shown in FIG. Separated from the sapphire substrate 41. Thereby, a rod-shaped structure light emitting element including a rod-shaped semiconductor core 43 having an exposed portion 43a on one end side and a semiconductor layer 44a covering the covering portion 43b other than the exposed portion 43a of the semiconductor core 43 is obtained.

  In this way, a fine rod-shaped structure light emitting device separated from the sapphire substrate 41 can be manufactured. In the second embodiment, the diameter of the rod-shaped structure light emitting element is 1 μm and the length is 10 μm (in FIGS. 5-1 to 5-4, the length of the rod-shaped structure light emitting element is drawn short for easy understanding of the drawings. )

  In FIG. 5A to FIG. 5D, one bar-shaped light emitting element is shown, but a plurality of bar-shaped light emitting elements are provided on the sapphire substrate 41.

  The manufacturing method of the rod-shaped structure light emitting element of the second embodiment has the same effect as the manufacturing method of the rod-shaped structure light emitting element of the first embodiment.

  Further, after forming a growth mask 42 having a growth hole 42 a on the semiconductor film 45 formed on the sapphire substrate 41, n is formed on the exposed region of the semiconductor film 45 exposed by the growth hole a of the growth mask 42. By forming the rod-shaped semiconductor core 43 by crystal growth of the type GaN, it is possible to form the semiconductor core 43 with few crystal defects.

[Third Embodiment]
6-1 to 6-6 show process drawings of the method for manufacturing the rod-shaped structure light emitting device according to the third embodiment of the present invention.

  First, as shown in FIG. 6A, a growth mask 52 having a growth hole 52a is formed on a sapphire substrate 51 in a growth mask formation step. Here, the growth hole 52a of the growth mask 52 has a length substantially the same as or longer than the length of the semiconductor core 51 to be formed in a later step.

The growth mask 52 may be made of a material that can be selectively etched with respect to the semiconductor core and the semiconductor layer, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ). The growth hole 52a can be formed by a known lithography method and dry etching method used in a normal semiconductor process. At this time, the diameter of the growing semiconductor core depends on the size of the growth hole of the growth mask.

  In this growth mask forming step, a diaphragm as an example of a shape changing portion in which the shape of the cross section perpendicular to the axial direction of the growth hole 52a is changed along the axial direction on the inner peripheral side of the growth hole 52a of the growth mask 52. The part 50 is provided. The narrowed portion 50 is formed on the sapphire substrate 51 side of the growth hole 52a of the growth mask 52 so that the inner diameter becomes smaller toward the sapphire substrate 51 side, and an exposed region of the sapphire substrate 51 in the growth hole 52a is formed. The growth hole 52a is smaller than the cross section perpendicular to the axial direction of the portion other than the narrowed portion 50.

Next, as shown in FIG. 6B, in the semiconductor core forming process, n-type GaN is crystal-grown on the exposed region of the sapphire substrate 51 exposed through the growth hole 52a of the growth mask 52 using an MOCVD apparatus. As a result, a rod-shaped semiconductor core 53 having a substantially circular cross section is formed in the growth hole 52 a of the growth mask 52. The growth temperature is set to about 800 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for supplying n-type impurities, and hydrogen (H ₂ ) is used as a carrier gas. , An n-type GaN semiconductor core having Si as an impurity can be grown.

  Next, as shown in FIG. 6-3, in the growth mask removing step, the upper portion of the growth mask 52 is removed by etching to expose the covering portion 53b (shown in FIG. 6-5) of the semiconductor core 53, The growth mask 52b is left.

Next, as shown in FIG. 6-4, in the semiconductor layer forming step, the semiconductor made of p-type GaN on the entire surface of the sapphire substrate 51 so as to cover the covering portion 53b (shown in FIG. 6-5) of the rod-shaped semiconductor core 53. Layer 54 is formed. The formation temperature is set to about 900 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, and biscyclopentadienylmagnesium (Cp ₂ Mg) is used for supplying p-type impurities. P-type GaN with impurities as a dopant can be grown.

Next, as shown in FIG. 6-5, in the growth mask removing step, the region excluding the portion of the semiconductor layer 54 covering the semiconductor core 53 and the growth mask 52 are removed by lift-off, and the sapphire substrate of the rod-shaped semiconductor core 53 is obtained. An exposed portion 53a is formed by exposing the outer peripheral surface on the 51 side. In this state, the tip 53c on the sapphire substrate 51 side of the exposed portion 53a of the semiconductor core 53 is tapered. The end surface of the semiconductor core 53 opposite to the sapphire substrate 51 is covered with a semiconductor layer 54a. When the growth mask is composed of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), a semiconductor layer and a semiconductor layer that easily covers the semiconductor core can be obtained by using a solution containing hydrofluoric acid (HF). The growth mask can be etched without affecting the portion, and the region excluding the portion of the semiconductor layer covering the semiconductor core together with the growth mask can be removed by lift-off. In the growth mask removing process of this embodiment, lift-off is used, but a part of the semiconductor core may be exposed by etching. In the case of dry etching, by using CF ₄ or XeF ₂ , the growth mask can be easily etched without affecting the semiconductor core and the semiconductor layer portion covering the semiconductor core, and the semiconductor covering the semiconductor core together with the growth mask. Regions other than the layer portions can be removed.

  Next, in the separation step, the substrate is dipped in an isopropyl alcohol (IPA) aqueous solution, and the sapphire substrate 51 is vibrated along the substrate plane using ultrasonic waves (for example, several tens of kHz), whereby the tip 53c of the semiconductor core 53 is obtained. A stress is applied to the semiconductor core 53 covered with the semiconductor layer 54a so that the semiconductor core 53 covered with the semiconductor layer 54a is bent as shown in FIG. Separated from the sapphire substrate 51. As a result, a rod-shaped structure light emitting device including a rod-shaped semiconductor core 53 having an exposed portion 53a on one end side and a semiconductor layer 54a covering the coated portion 53b other than the exposed portion 53a of the semiconductor core 53 is obtained.

  In this way, a fine rod-shaped structure light emitting element separated from the sapphire substrate 51 can be manufactured. In this third embodiment, the diameter of the rod-shaped structure light-emitting element is 1 μm and the length is 10 μm (FIGS. 6-1 to 6-6 depict the length of the rod-shaped structure light-emitting element to be short in order to make the drawings easier to see. )

  The manufacturing method of the rod-shaped structure light emitting element of the third embodiment has the same effect as the manufacturing method of the rod-shaped structure light emitting element of the first embodiment.

  In the third embodiment, since all of the semiconductor core 53 is formed in the growth hole 52a of the growth mask 52, the shape of the entire semiconductor core 53 can be easily controlled.

[Fourth Embodiment]
7-1 to 7-4 show process drawings of the method for manufacturing the rod-shaped structure light emitting device of the fourth embodiment of the present invention.

First, as shown in FIG. 7A, in the semiconductor film forming step, a semiconductor film 66 made of n-type GaN is formed on a sapphire substrate 61 as an example of a substrate body, and then in the growth mask forming step, a semiconductor is formed. A growth mask 62 having a growth hole 62 a is formed on the film 66. For the growth mask, a material that can be selectively etched with respect to the semiconductor core and the semiconductor layer, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), can be used. The growth hole 62a can be formed by a known lithography method and dry etching method used in a normal semiconductor process. At this time, the diameter of the growing semiconductor core depends on the size of the growth hole of the growth mask.

  In this growth mask formation step, a constriction as an example of a shape change portion in which the shape of the cross section perpendicular to the axial direction of the growth hole 62a is changed along the axial direction on the inner peripheral side of the growth hole 62a of the growth mask 62. A portion 60 is provided. The constricted portion 60 is formed at a position spaced a predetermined distance from the sapphire substrate 61 side of the growth mask 62 (see the eighth embodiment for the method of forming the constricted portion).

Next, as shown in FIG. 7B, in the semiconductor core formation step, n-type GaN is grown on the exposed region of the semiconductor film 66 exposed by the growth hole 62a of the growth mask 62 by using an MOCVD apparatus. As a result, a rod-shaped semiconductor core 63 having a substantially circular cross section is formed. The growth temperature is set to about 800 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for supplying n-type impurities, and hydrogen (H ₂ ) is used as a carrier gas. , An n-type GaN semiconductor core having Si as an impurity can be grown.

Next, in the semiconductor layer forming step, a semiconductor layer 64 made of p-type GaN is formed on the entire surface of the sapphire substrate 61 so as to cover the covering portion 63b (shown in FIG. 7-3) of the rod-shaped semiconductor core 63. The formation temperature is set to about 900 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, and biscyclopentadienylmagnesium (Cp ₂ Mg) is used for supplying p-type impurities. P-type GaN with impurities as a dopant can be grown.

  Next, as shown in FIG. 7C, in the growth mask removing step, the region excluding the portion of the semiconductor layer 64 covering the semiconductor core 63 and the growth mask 62 are removed by lift-off to remove the sapphire substrate of the rod-shaped semiconductor core 63. The exposed portion 63a is formed by exposing the outer peripheral surface on the 61 side. In this state, an annular groove 65 is formed in the exposed portion 63 a of the semiconductor core 63. The end surface of the semiconductor core 63 opposite to the sapphire substrate 61 is covered with a semiconductor layer 64a.

When the growth mask is composed of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), a semiconductor layer and a semiconductor layer that easily covers the semiconductor core can be obtained by using a solution containing hydrofluoric acid (HF). The growth mask can be etched without affecting the portion, and the region excluding the portion of the semiconductor layer covering the semiconductor core together with the growth mask can be removed by lift-off. In the growth mask removing process of this embodiment, lift-off is used, but a part of the semiconductor core may be exposed by etching. In the case of dry etching, by using CF ₄ or XeF ₂ , the growth mask can be easily etched without affecting the semiconductor core and the semiconductor layer portion covering the semiconductor core, and the semiconductor covering the semiconductor core together with the growth mask. Regions other than the layer portions can be removed.

  Next, in the separation step, the substrate is immersed in an isopropyl alcohol (IPA) aqueous solution, and the sapphire substrate 61 is vibrated along the substrate plane using ultrasonic waves (for example, several tens of kilohertz). As shown in FIG. 7-4, stress is applied to the semiconductor core 63 covered with the semiconductor layer 64a so that the semiconductor core 63 covered with the semiconductor layer 64a is separated by the groove 65, and the sapphire substrate is bent. The core remaining part 63c after cutting remains on the 61 side. As a result, a rod-shaped structure light emitting device including a rod-shaped semiconductor core 63 having an exposed portion 63a on one end side and a semiconductor layer 64a covering the covering portion 63b other than the exposed portion 63a of the semiconductor core 63 is obtained.

  In this way, a fine rod-shaped structure light emitting device separated from the sapphire substrate 61 can be manufactured. In the second embodiment, the diameter of the rod-shaped structure light-emitting element is 1 μm and the length is 10 μm (in FIGS. 7-1 to 7-4, the length of the rod-shaped structure light-emitting element is drawn short to make the drawings easier to see. )

  The manufacturing method of the rod-shaped structure light emitting element of the fourth embodiment has the same effect as the manufacturing method of the rod-shaped structure light emitting element of the first embodiment.

  Further, after forming a growth mask 62 having a growth hole 62 a on the semiconductor film 66 formed on the sapphire substrate 61, n is formed on the exposed region of the semiconductor film 66 exposed by the growth hole a of the growth mask 62. By forming the rod-shaped semiconductor core 63 by crystal growth of the type GaN, the semiconductor core 63 with few crystal defects can be formed.

  Moreover, according to the manufacturing method of the rod-shaped structure light emitting device of the fourth embodiment, in the growth mask formation step, the neck is formed at a position spaced from the inner circumference side of the growth hole 62a of the growth mask 62 and a predetermined distance from the sapphire substrate 61 side. Since the annular groove portion 65 is formed in the semiconductor core 63 by the constricted portion 60 as the shape changing portion provided in the semiconductor core 63, the semiconductor core 63 can be easily separated by the annular groove portion 65 in the separation step. Variations in the length of the rod-shaped structure light emitting elements can be reduced.

[Fifth Embodiment]
FIGS. 8-1 to FIGS. 8-15 show process drawings of the method for manufacturing the rod-shaped structure light emitting device of the fifth embodiment of the present invention.

  First, as shown in FIG. 8A, a sapphire substrate 71 is prepared. If necessary, the sapphire substrate 71 may be cleaned with a cleaning agent or pure water, or may be subjected to substrate processing such as marking.

Next, in a growth mask formation step, SiO ₂ or Si ₃ N ₄ is deposited on the sapphire substrate 71 to form a growth mask 72, and a metal lift-off layer 73 is formed on the growth mask 72.

  Next, as illustrated in FIG. 8B, a resist pattern 74 having a hole 74 a is formed on the metal lift-off layer 73.

  Next, as shown in FIG. 8C, using the resist pattern 74 as a mask, a hole 75 penetrating the metal lift-off layer 73 and extending to the vicinity of the sapphire substrate 71 is formed in the growth mask 72 by dry etching. Here, since a part of the growth mask 72 is left at the bottom of the hole 75 and the sapphire substrate 71 is not dry-etched, the surface of the sapphire substrate 71 is not damaged.

  Next, as shown in FIG. 8D, a growth hole 72a having a diameter larger than that of the hole 74a of the resist pattern 74 is formed in the growth mask 72 by wet etching.

  At this time, an aperture portion 70 as an example of a shape changing portion in which the shape of the cross section orthogonal to the axial direction of the growth hole 72a is changed along the axial direction is provided on the inner peripheral side of the growth hole 72a of the growth mask 72. ing. The narrowed portion 70 is formed on the sapphire substrate 71 side of the growth hole 72a of the growth mask 72 so that the inner diameter becomes smaller toward the sapphire substrate 71 side, and the exposed region of the sapphire substrate 71 in the growth hole 72a is formed. The cross section perpendicular to the axial direction of the portion other than the narrowed portion 10 of the growth hole 72a is smaller.

  Next, as shown in FIG. 8-5, after removing the resist pattern 74 (shown in FIG. 8-4) by lift-off, the substrate is cleaned.

  Next, as shown in FIG. 8-6, in the semiconductor core formation process, n-type GaN is crystal-grown on the exposed region of the sapphire substrate 71 exposed by the growth hole 72a of the growth mask 72 using an MOCVD apparatus. Thus, the initial growth portion 76 is formed.

  Next, as shown in FIG. 8-7, in the catalyst metal layer forming step, the catalyst metal is deposited on the initial growth portion 76 to form the catalyst metal layer 77. This catalytic metal layer dissolves and incorporates compound semiconductor materials such as Ga, N, In, and Al, and impurity materials such as Si and Mg, and is difficult to form a compound with itself. , Materials such as Au can be used. At this time, the metal layer 78 is also formed on the metal lift-off layer 73 at the same time.

  Next, as shown in FIG. 8-8, the metal lift-off layer 73 (shown in FIG. 8-7) is removed together with the metal layer 78 (shown in FIG. 8-7) by lift-off, and the substrate is cleaned.

  Next, as shown in FIG. 8-9, a rod-shaped semiconductor core 81 having a substantially circular cross section is obtained by crystal growth of n-type GaN at the interface between the initial growth portion 76 and the catalytic metal layer 77 using an MOCVD apparatus. Form.

  Here, the diameter of the semiconductor core 81 to be grown is determined by the inner diameter of the growth hole 72a because the diameter of the catalytic metal layer 77 does not expand beyond the inner diameter of the growth hole 72a in the growth hole 72a of the growth mask 72. The diameter of the semiconductor core 81 is determined by the diameter of the catalyst metal layer that aggregates in an island shape after the height of the growing semiconductor core 81 exceeds the height of the growth mask 72 (depth of the growth hole 72a). . Therefore, even if the height of the growing semiconductor core 81 exceeds the height of the growth mask 72 (depth of the growth hole 72a), an appropriate film thickness is set so that the islands are aggregated in an island shape with substantially the same diameter as the growth hole 72a. By forming the catalytic metal layer 77, the semiconductor core 81 having the same diameter can be grown even when the height of the growth mask 72 (depth of the growth hole 72a) is exceeded.

  When the height of the growing semiconductor core 81 exceeds the height of the growth mask 72 (depth of the growth hole 72a), the catalytic metal layer is aggregated in an island shape with a diameter larger than that of the growth hole 72a. By controlling the film thickness 77, the covered portion of the semiconductor core 81 can be grown with a diameter larger than the diameter of the exposed portion of the semiconductor core 81 in the growth hole 72a.

  Next, as shown in FIG. 8-10, in the quantum well layer forming step, the entire surface of the substrate 71 is covered so as to cover the semiconductor core 81 with the island-shaped catalytic metal layer 77 held at the tip of the semiconductor core 81. Then, an MQW (Multiple Quantum Well) layer 82 is formed.

  Here, the MQW layer 82 is formed by growing the n-type GaN semiconductor core 81 in the MOCVD apparatus as described above, and then forming the p-type GaN barrier layer and the p-type InGaN on the n-type GaN semiconductor core 81. The quantum well layer is formed by alternately repeating. Instead of the MQW layer 82, a single p-type InGaN quantum well layer may be used, or a p-type AlGaN layer may be inserted as an electron blocking layer between the p-type InGaN layer and the p-type GaN layer. Good.

Next, in the semiconductor layer forming step, the p-type GaN is applied to the entire surface of the substrate so as to cover the MQW layer 82 while holding the island-shaped catalytic metal layer 77 at the tip of the semiconductor core 81 covered with the MQW layer 82. A semiconductor layer 83 made of is formed. By setting the temperature of the MOCVD apparatus to about 900 ° C., using trimethylgallium (TMG) and ammonia (NH ₃ ) as growth gases and biscyclopentadienylmagnesium (Cp ₂ Mg) for supplying p-type impurities, It is possible to grow p-type GaN having (Mg) as an impurity.

  In the quantum well layer forming step, the growth rate of the MQW layer 82 at the interface between the catalytic metal layer 77 and the end face of the semiconductor core 81 is 10 to 100 times larger than the growth rate on the side surface side of the semiconductor core 81. Therefore, the film thickness on the end face side of the semiconductor core 81 is thicker than that on the side face side. Similarly, in the semiconductor layer forming step, the growth rate of the semiconductor layer 83 at the interface between the catalytic metal layer 77 and the end face side of the semiconductor core 81 covered with the MQW layer 82 is covered with the MQW layer 82. Since the growth rate on the side surface side of the broken semiconductor core 81 is 10 to 100 times larger, the film thickness on the end surface side of the semiconductor core 81 covered with the MQW layer 82 becomes thicker than that on the side surface side.

Next, as shown in FIGS. 8-11, the catalyst metal layer 77 (shown in FIGS. 8-10) is selectively removed by wet etching, and then washed with pure water, for example. Then, annealing for activating the p-type GaN is performed. The catalytic metal layer 77 may be removed by dry etching RIE (Reactive Ion Etching). At this time, by using SiCl ₄ for RIE, etching having anisotropy in GaN can be easily performed.

  Next, as shown in FIG. 8-12, a conductive film 84 made of polysilicon or ITO is formed on the semiconductor layer 83, and an annealing process is further performed, so that a gap between the semiconductor layer 83 and the conductive film 84 is obtained. Reduce resistance.

  Next, as shown in FIG. 8-13, the conductive film 84, the semiconductor layer 83, and the MQW layer 82 are sequentially etched to leave the conductive film 84a, the semiconductor layer 83a, and the MQW layer 82a on one end side of the semiconductor core 81. On the other hand, the growth mask 72 is left on the other end side of the semiconductor core 81. At this time, the upper side of the conductive film 84 is removed and a part of the upper side of the semiconductor layer 83 is removed. In the semiconductor layer 83 before etching, the radial thickness of the portion covering the outer peripheral surface of the semiconductor core 81 is removed. In addition, since the axial thickness of the portion covering the upper end surface of the semiconductor core 81 is thicker, the upper end surface of the semiconductor core 81 is difficult to be exposed.

  Next, as shown in FIG. 8-14, the growth mask 72 (shown in FIG. 8-13) is removed by etching. In this state, the tip 81c of the exposed portion 81a of the semiconductor core 81 on the sapphire substrate 71 side is tapered.

  Next, in the separation step, the sapphire substrate 71 is immersed in an IPA (isopropyl alcohol) aqueous solution, and the sapphire substrate 71 is vibrated along the substrate plane using, for example, an ultrasonic wave of several tens of KHz, thereby standing on the sapphire substrate 71. As shown in FIG. 8-15, the semiconductor core 81 is separated from the sapphire substrate 71 by applying stress to the semiconductor core 81 so as to be bent at the interface between the tip 81c of the semiconductor core 81 to be provided and the sapphire substrate 71. It is.

  9, the MQW layer 82a covering the rod-shaped semiconductor core 81 having the exposed portion 81a on one end side and the covering portion 81b other than the exposed portion 81a of the semiconductor core 81, as shown in FIG. A rod-like structure light emitting device including a semiconductor layer 83a (shown in FIG. 8-15), a conductive layer 84a (shown in FIG. 8-15), and a conductive layer 84a is obtained.

  The manufacturing method of the rod-shaped structure light emitting element of the fifth embodiment has the same effect as the manufacturing method of the rod-shaped structure light emitting element of the first embodiment.

  Further, by forming the MQW layer 82a between the semiconductor core 81 and the semiconductor layer 83a, the light emission efficiency can be improved by the quantum confinement effect of the MQW layer 82a.

  Further, in the method for manufacturing the rod-shaped structure light emitting element, the catalytic metal layer 77 is formed on the exposed region of the sapphire substrate 71 exposed by the growth hole 72a of the growth mask 72 after the growth mask forming step and before the semiconductor core forming step. After the formation, the rod-shaped semiconductor core 81 is formed by crystal growth of n-type GaN from the interface between the catalytic metal layer 77 and the sapphire substrate 71, whereby the semiconductor core 81 with few crystal defects can be formed. Therefore, it is possible to realize a rod-shaped structure light emitting device with good characteristics.

  Further, after the semiconductor core formation step, crystal growth from the outer peripheral surface of the semiconductor core 81 and the interface between the catalyst metal layer 77 and the tip of the semiconductor core 81 with the catalyst metal layer 77 held at the tip of the semiconductor core 81. By forming the MQW layer 82 and the semiconductor layer 83 covering the surface of the semiconductor core 81, crystal growth from the interface between the catalytic metal layer 77 and the semiconductor core 81 is promoted more than the outer peripheral surface of the semiconductor core 81. The MQW layer 82 and the semiconductor layer 83 can be made thicker in the axial direction of the portion covering the end surface on the other end side of the semiconductor core 81 than in the radial thickness of the portion covering the outer peripheral surface of the semiconductor core 81. Become.

  In the manufacturing method of the rod-shaped structure light emitting element, the MQW layer 82a and the semiconductor layer 83a at the end of the semiconductor core 81 are thickened, and the semiconductor core 81 is not etched in the etching step in FIGS. A cap layer made of p-type GaN for short-circuit protection is not required at the end of each.

  In the semiconductor core formation step, since the initial growth portion 76 made of n-type GaN is formed on the exposed region of the sapphire substrate 71 exposed by the growth hole 72a of the growth mask 72, the n-type GaN on the sapphire substrate 71. Therefore, since the n-type GaN film having a thickness of several μm is not formed, the processing time can be shortened and the growth cost can be reduced. Further, since there is no need to etch n-type GaN, the amount of wasted GaN used can be reduced.

  Further, the light extraction efficiency can be improved by changing the surface shape of the semiconductor core 81 on the sapphire substrate 71 side according to the shape of the growth hole of the growth mask.

  Further, by controlling the shape of the growth hole of the growth mask without using dry etching, the tip of the semiconductor core 81 on the sapphire substrate 71 side is tapered, so that the process can be simplified and the length of the semiconductor core 81 can be reduced. The variation in thickness can be reduced. Furthermore, it is not necessary to etch the underlying n-type GaN or the sapphire substrate before the semiconductor core 81 is separated, and the damage to the conductive film and the surface of the semiconductor core 81 can be reduced.

  Moreover, in the manufacturing method of the said rod-shaped structure light emitting element, since dry etching is not performed to the sapphire substrate 71, there is no damage on the surface of the sapphire substrate 71, and the removal process of a damage layer is unnecessary.

  Note that, by forming the initial growth portion 76 made of n-type GaN as a base on the sapphire substrate 71, variations in the initial growth can be suppressed, so that variations in length after growth can be reduced.

[Sixth Embodiment]
10-1 to 10-13 show process drawings of the method for manufacturing the rod-shaped structure light emitting device according to the sixth embodiment of the present invention.

  First, as shown in FIG. 10A, a sapphire substrate 91 is prepared. If necessary, the sapphire substrate 91 may be cleaned with a cleaning agent or pure water, or may be subjected to substrate processing such as marking.

Next, in the growth mask formation step, SiO ₂ or Si ₃ N ₄ is deposited on the sapphire substrate 91 to form a growth mask 92.

  Next, as illustrated in FIG. 10B, a resist pattern 93 having a hole 93 a is formed on the growth mask 92.

  Next, as shown in FIG. 10-3, a hole 94 extending to the vicinity of the sapphire substrate 91 is formed in the growth mask 92 by dry etching using the resist pattern 93 as a mask. Here, since a part of the growth mask 92 is left at the bottom of the hole 94 and the sapphire substrate 91 is not dry-etched, the surface of the sapphire substrate 91 is not damaged.

  Next, as shown in FIG. 10-4, a growth hole 92a having a diameter larger than that of the hole 93a of the resist pattern 93 is formed in the growth mask 92 by wet etching.

  At this time, an aperture portion 90 as an example of a shape changing portion in which the shape of the cross section orthogonal to the axial direction of the growth hole 92a is changed along the axial direction is provided on the inner peripheral side of the growth hole 92a of the growth mask 92. ing. The narrowed portion 90 is formed on the sapphire substrate 91 side of the growth hole 92a of the growth mask 92 so that the inner diameter becomes smaller toward the sapphire substrate 91 side, and the exposed region of the sapphire substrate 91 in the growth hole 92a is formed. The growth hole 92a is smaller than the cross section perpendicular to the axial direction of the portion other than the narrowed portion 90.

  Next, as shown in FIG. 10-5, in the catalyst metal layer forming step, the catalyst metal layer 97 is formed by depositing the catalyst metal on the bottom of the growth hole 92a. This catalytic metal layer dissolves and incorporates compound semiconductor materials such as Ga, N, In, and Al, and impurity materials such as Si and Mg, and is difficult to form a compound with itself. , Materials such as Au can be used. At this time, the metal layer 98 is also formed on the resist pattern 93 at the same time.

  Next, as shown in FIG. 10-6, the resist pattern 93 (shown in FIG. 10-5) is removed together with the metal layer 98 (shown in FIG. 10-5) by lift-off, and the substrate is cleaned.

  Next, as shown in FIG. 10-7, in the semiconductor core formation step, n-type GaN is grown on the exposed region of the sapphire substrate 91 exposed by the growth hole 92a of the growth mask 92 using an MOCVD apparatus. As a result, a rod-shaped semiconductor core 101 having a substantially circular cross section is formed.

  Here, the diameter of the semiconductor core 101 to be grown is determined by the inner diameter of the growth hole 92a because the diameter of the catalytic metal layer 97 does not expand beyond the inner diameter of the growth hole 92a in the growth hole 92a of the growth mask 92. The diameter of the semiconductor core 101 is determined by the diameter of the catalyst metal layer that aggregates in an island shape after the height of the growing semiconductor core 101 exceeds the height of the growth mask 92 (depth of the growth hole 92a). . Therefore, even if the height of the growing semiconductor core 101 exceeds the height of the growth mask 92 (depth of the growth hole 92a), an appropriate film thickness is formed so that the islands are aggregated in an island shape with substantially the same diameter as the growth hole 92a. By forming the catalytic metal layer 97, the semiconductor core 101 having the same diameter can be grown even when the height of the growth mask 92 (depth of the growth hole 92a) is exceeded.

  When the height of the growing semiconductor core 101 exceeds the height of the growth mask 92 (depth of the growth hole 92a), the catalyst metal layer is aggregated in an island shape with a diameter larger than that of the growth hole 92a. By controlling the film thickness 97, the covered portion of the semiconductor core 101 can be grown with a diameter larger than the diameter of the exposed portion of the semiconductor core 101 in the growth hole 92a.

  Next, as shown in FIG. 10-8, in the quantum well layer forming step, the entire surface of the substrate 91 is covered so as to cover the semiconductor core 101 with the island-shaped catalytic metal layer 97 held at the tip of the semiconductor core 101. Then, an MQW (Multiple Quantum Well) layer 102 is formed.

  Here, the MQW layer 102 is formed by alternately growing a barrier layer made of p-type GaN and a quantum well layer made of p-type InGaN after growing the n-type GaN semiconductor core 101 in the MOCVD apparatus as described above. To form. Instead of the MQW layer 102, a single p-type InGaN quantum well layer may be used, or a p-type AlGaN layer may be provided as an electron blocking layer between the p-type InGaN layer and the p-type GaN layer. Good.

Next, in the semiconductor layer formation step, the p-type GaN is applied to the entire surface of the substrate so as to cover the MQW layer 102 while holding the island-shaped catalytic metal layer 97 at the tip of the semiconductor core 101 covered with the MQW layer 102. A semiconductor layer 103 made of is formed. By setting the temperature of the MOCVD apparatus to about 900 ° C., using trimethylgallium (TMG) and ammonia (NH ₃ ) as growth gases and biscyclopentadienylmagnesium (Cp ₂ Mg) for supplying p-type impurities, It is possible to grow p-type GaN having (Mg) as an impurity.

  In the quantum well layer forming step, the growth rate of the MQW layer 102 at the interface between the catalytic metal layer 97 and the end surface of the semiconductor core 101 is 10 to 100 times larger than the growth rate on the side surface side of the semiconductor core 101. Therefore, the film thickness on the end surface side of the semiconductor core 101 is thicker than that on the side surface side. Similarly, in the semiconductor layer forming step, the growth rate of the semiconductor layer 103 at the interface between the catalytic metal layer 97 and the end face side of the semiconductor core 101 covered with the MQW layer 102 is covered with the MQW layer 102. Since the growth rate on the side surface side of the broken semiconductor core 101 is 10 to 100 times larger, the film thickness on the end surface side of the semiconductor core 101 covered with the MQW layer 102 becomes thicker than that on the side surface side.

Next, as shown in FIG. 10-9, the catalyst metal layer 97 (shown in FIG. 10-8) is selectively removed by wet etching, and then washed with pure water, for example. Then, annealing for activating the p-type GaN is performed. The catalytic metal layer 97 may be removed by dry etching RIE. At this time, by using SiCl ₄ for RIE, etching having anisotropy in GaN can be easily performed.

  Next, as shown in FIG. 10-10, a conductive film 104 made of polysilicon or ITO is formed on the semiconductor layer 103, and an annealing process is performed, so that the gap between the semiconductor layer 103 and the conductive film 104 is increased. Reduce resistance.

  Next, as shown in FIGS. 10-11, the conductive film 104, the semiconductor layer 103, and the MQW layer 102 are sequentially etched to leave the conductive film 104 a, the semiconductor layer 103 a, and the MQW layer 102 a on one end side of the semiconductor core 101. On the other hand, the growth mask 92 is left on the other end side of the semiconductor core 101. At this time, the upper side of the conductive film 104 is removed and a part of the upper side of the semiconductor layer 103 is removed. In the semiconductor layer 103 before etching, the radial thickness of the portion covering the outer peripheral surface of the semiconductor core 101 is removed. In addition, since the axial thickness of the portion covering the upper end surface of the semiconductor core 101 is thicker, the upper end surface of the semiconductor core 101 is difficult to be exposed.

  Next, as shown in FIG. 10-12, the growth mask 92 (shown in FIG. 10-13) is removed by etching. In this state, the tip 101c on the sapphire substrate 91 side of the exposed portion 101a of the semiconductor core 101 has a tapered shape.

  Next, in the separation step, the sapphire substrate 91 is immersed in an IPA (isopropyl alcohol) aqueous solution, and the sapphire substrate 91 is vibrated along the substrate plane using, for example, an ultrasonic wave of several tens of KHz to stand on the sapphire substrate 91. Stress is applied to the semiconductor core 101 so as to be bent at the interface between the tip 101c of the semiconductor core 101 to be provided and the sapphire substrate 91, and the semiconductor core 101 is separated from the sapphire substrate 91 as shown in FIG. It is.

  The manufacturing method of the rod-shaped structure light emitting element of the sixth embodiment has the same effects as the manufacturing method of the rod-shaped structure light emitting element of the fifth embodiment except for the effect of the initial growth portion.

[Seventh Embodiment]
11-1 to 11-14 show process drawings of the method for manufacturing the rod-shaped structure light emitting device according to the seventh embodiment of the present invention.

  First, as shown in FIG. 11A, a sapphire substrate 111 is prepared. If necessary, the sapphire substrate 111 may be cleaned with a cleaning agent or pure water, or may be subjected to substrate processing such as marking.

Next, in the growth mask formation step, SiO ₂ or Si ₃ N ₄ is deposited on the sapphire substrate 111 to form the growth mask 112. Here, the film thickness of the growth mask 112 is set to be the same as the length of the semiconductor core to be formed in a later process.

  Next, as illustrated in FIG. 11B, a resist pattern 113 having a hole 113 a is formed on the growth mask 112.

  Next, as shown in FIG. 11C, a hole 114 extending to the vicinity of the sapphire substrate 111 is formed in the growth mask 112 by dry etching using the resist pattern 113 as a mask. Here, since a part of the growth mask 112 is left at the bottom of the hole 114 and the sapphire substrate 111 is not dry-etched, the surface of the sapphire substrate 111 is not damaged.

  Next, as shown in FIG. 11-4, a growth hole 112a having a diameter larger than that of the hole 113a of the resist pattern 113 is formed in the growth mask 112 by wet etching.

  At this time, the narrowed portion 110 as an example of the shape changing portion in which the shape of the cross section perpendicular to the axial direction of the growth hole 112a is changed along the axial direction is provided on the inner peripheral side of the growth hole 112a of the growth mask 112. ing. The narrowed portion 110 is formed on the sapphire substrate 111 side of the growth hole 112a of the growth mask 112 so that the inner diameter becomes smaller toward the sapphire substrate 111 side, and an exposed region of the sapphire substrate 111 in the growth hole 112a is formed. The growth hole 112a is smaller than the cross section perpendicular to the axial direction of the portion other than the narrowed portion 110.

  Next, as shown in FIG. 11-5, in the catalyst metal layer forming step, the catalyst metal layer 117 is formed by depositing the catalyst metal on the bottom of the growth hole 112a. This catalytic metal layer dissolves and incorporates compound semiconductor materials such as Ga, N, In, and Al, and impurity materials such as Si and Mg, and is difficult to form a compound with itself. , Materials such as Au can be used. At this time, the metal layer 118 is also formed on the resist pattern 113 at the same time.

  Next, as shown in FIG. 11-6, the resist pattern 113 (shown in FIG. 11-5) is removed together with the metal layer 118 (shown in FIG. 11-5) by lift-off, and the substrate is cleaned.

  Next, as shown in FIG. 11-7, in the semiconductor core formation process, n-type GaN is grown on the exposed region of the sapphire substrate 111 exposed by the growth hole 112a of the growth mask 112 using an MOCVD apparatus. As a result, a rod-shaped semiconductor core 121 having a substantially circular cross section is formed in the growth hole 112a.

  Here, the diameter of the growing semiconductor core 121 is determined by the inner diameter of the growth hole 112a because the diameter of the catalytic metal layer 117 does not expand beyond the inner diameter of the growth hole 112a in the growth hole 112a of the growth mask 112.

  Next, as shown in FIG. 11-8, the upper side of the growth mask 112 is removed by dry etching to leave a growth mask 112a covering the exposed portion of the semiconductor core 121 exposed in a later step.

  Next, as shown in FIG. 11-9, in the quantum well layer formation step, the entire surface of the substrate 111 is covered so as to cover the semiconductor core 121 while holding the island-shaped catalytic metal layer 117 at the tip of the semiconductor core 121. Then, an MQW (Multiple Quantum Well) layer 122 is formed.

  Here, the MQW layer 122 is formed by alternately growing a barrier layer made of p-type GaN and a quantum well layer made of p-type InGaN after the growth of the n-type GaN semiconductor core 121 in the MOCVD apparatus as described above. To form. Instead of the MQW layer 122, a single p-type InGaN quantum well layer may be used, or a p-type AlGaN layer may be inserted as an electron blocking layer between the p-type InGaN layer and the p-type GaN layer. Good.

Next, in the semiconductor layer forming step, the p-type GaN is applied to the entire surface of the substrate so as to cover the MQW layer 122 while holding the island-shaped catalytic metal layer 117 at the tip of the semiconductor core 121 covered with the MQW layer 122. A semiconductor layer 123 made of is formed. By setting the temperature of the MOCVD apparatus to about 900 ° C., using trimethylgallium (TMG) and ammonia (NH ₃ ) as growth gases and biscyclopentadienylmagnesium (Cp ₂ Mg) for supplying p-type impurities, It is possible to grow p-type GaN having (Mg) as an impurity.

  In the quantum well layer forming step, the growth rate of the MQW layer 122 at the interface between the catalytic metal layer 117 and the end face of the semiconductor core 121 is 10 to 100 times larger than the growth rate on the side surface side of the semiconductor core 121. Therefore, the film thickness on the end face side of the semiconductor core 121 is thicker than that on the side face side. Similarly, in the semiconductor layer forming step, the growth rate of the semiconductor layer 123 at the interface between the catalytic metal layer 117 and the end face side of the semiconductor core 121 covered with the MQW layer 122 is covered with the MQW layer 122. Since the growth rate on the side surface side of the broken semiconductor core 121 is 10 to 100 times larger, the film thickness on the end surface side of the semiconductor core 121 covered with the MQW layer 122 becomes thicker than that on the side surface side.

Next, as shown in FIG. 11-10, the catalyst metal layer 117 (shown in FIG. 11-9) is selectively removed by wet etching, and then washed with pure water, for example. Then, annealing for activating the p-type GaN is performed. The catalytic metal layer 117 may be removed by dry etching RIE. At this time, by using SiCl ₄ for RIE, etching having anisotropy in GaN can be easily performed.

  Next, as illustrated in FIGS. 11 to 11, a conductive film 124 made of polysilicon or ITO is formed on the semiconductor layer 123, and an annealing process is performed, so that the gap between the semiconductor layer 123 and the conductive film 124 is formed. Reduce resistance.

  Next, as shown in FIG. 11-12, the conductive film 124, the semiconductor layer 123, and the MQW layer 122 are sequentially etched to leave the conductive film 124a, the semiconductor layer 123a, and the MQW layer 122a on one end side of the semiconductor core 121. On the other hand, the growth mask 112 is left on the other end side of the semiconductor core 121. At this time, the upper side of the conductive film 124 is removed and a part of the upper side of the semiconductor layer 123 is removed. In the semiconductor layer 123 before etching, the radial thickness of the portion covering the outer peripheral surface of the semiconductor core 121 is removed. In addition, since the axial thickness of the portion covering the upper end face of the semiconductor core 121 is thick, the upper end face of the semiconductor core 121 is difficult to be exposed.

  Next, as shown in FIGS. 11-12, the growth mask 112a (shown in FIGS. 11-13) is removed by etching. In this state, the tip 121c on the sapphire substrate 111 side of the exposed portion 121a of the semiconductor core 121 has a tapered shape.

  Next, in the separation step, the sapphire substrate 111 is immersed in an IPA (isopropyl alcohol) aqueous solution, and the sapphire substrate 111 is vibrated along the substrate plane by using, for example, ultrasonic waves of several tens of KHz, thereby standing on the sapphire substrate 111. As shown in FIG. 11-13, the semiconductor core 121 is separated from the sapphire substrate 111 by applying a stress to the semiconductor core 121 so as to be bent at the interface between the tip 121c of the semiconductor core 121 to be provided and the sapphire substrate 111. It is.

  The manufacturing method of the rod-shaped structure light emitting device of the seventh embodiment has the same effects as the manufacturing method of the rod-shaped structure light emitting device of the fifth embodiment except for the effect of the initial growth portion.

[Eighth Embodiment]
12-1 to 12-7 show process drawings of the method for manufacturing the rod-shaped structure light emitting device of the eighth embodiment of the present invention. In the eighth embodiment, a specific example will be described in which a constricted portion is formed at a position spaced a predetermined distance from the inner peripheral side of the growth hole of the growth mask and the substrate side.

First, as shown in FIG. 12A, in the growth mask formation step, SiO ₂ or Si ₃ N ₄ is deposited on the sapphire substrate 131 to form a growth mask 132.

  Next, as illustrated in FIG. 12B, a resist pattern 133 having a hole 133 a is formed on the growth mask 132.

  Next, as shown in FIG. 12C, a hole 134 extending toward the sapphire substrate 131 is formed in the growth mask 132 by dry etching using the resist pattern 133 as a mask. Here, the hole 134 is formed halfway in the film thickness direction of the growth mask 132 so that the portion where the constricted portion is to be formed in the subsequent process is the bottom.

  Next, as shown in FIG. 12-4, a growth hole 132a having a diameter larger than that of the hole 133a of the resist pattern 133 is formed in the growth mask 132 by wet etching.

  Next, as shown in FIG. 12-5, after the hole 134 is once filled with a resist, the hole 134 penetrating to the sapphire substrate 131 is formed in the resist pattern 135 and the growth mask 132 by dry etching. Thereby, the diameter of the growth hole 132a formed in FIG. 12-4 is reduced.

  Next, as shown in FIG. 12-6, a growth hole 132b having a diameter larger than that of the hole 134 of the resist pattern 133 is formed below the growth mask 132 by wet etching.

  Next, as shown in FIG. 12-7, after removing the resist 135, the substrate is washed.

  Thus, according to the method for manufacturing the rod-shaped structure light emitting device of the eighth embodiment, the constricted portion 130 can be easily formed in the growth mask 132.

  According to the method for manufacturing the rod-shaped structure light emitting device of the eighth embodiment, in the growth mask forming step, the rod is provided so as to be constricted at a position spaced from the inner peripheral side of the growth hole 132a of the growth mask 132 and the sapphire substrate 131 side. In the subsequent semiconductor core forming process, the annular groove portion is formed in the semiconductor core by the constricted portion 130 as the shape change portion thus formed. Therefore, the semiconductor core 63 can be easily separated by the annular groove portion 65 in the separation step. This makes it possible to reduce variation in the length of the rod-shaped structure light emitting element.

[Ninth Embodiment]
Next, a light emitting device, a backlight, a lighting device, and a display device each including a rod-shaped structure light emitting element according to a ninth embodiment of the invention will be described. In the ninth embodiment, the rod-shaped structure light emitting elements of the first to eighth embodiments are arranged on an insulating substrate. The arrangement of the rod-shaped structure light-emitting elements is the same as that disclosed in Japanese Patent Application No. 2007-102848 (Japanese Patent Application Laid-Open No. 2008-260073), “Microstructure Arrangement Method, Substrate Arranged with Fine Structure, and Integrated Circuit Device” And display device ".

  FIG. 13 shows a plan view of an insulating substrate used in the light emitting device, backlight, illumination device and display device of the ninth embodiment. As shown in FIG. 13, metal electrodes 301 and 302 are formed on the surface of the insulating substrate 300. The insulating substrate 300 is an insulating material such as glass, ceramic, aluminum oxide, resin, or a substrate in which a silicon oxide film is formed on a semiconductor surface such as silicon, and the surface is insulative. When a glass substrate is used, it is desirable to form a base insulating film such as a silicon oxide film or a silicon nitride film on the surface.

  The metal electrodes 301 and 302 are formed in a desired electrode shape using a printing technique. The metal film and the photosensitive film may be uniformly laminated, and a desired electrode pattern may be exposed and etched.

  Although not shown in FIG. 13, pads are formed on the metal electrodes 301 and 302 so that a potential can be applied from the outside. A rod-shaped structure light emitting element is arranged in a portion (arrangement region) where the metal electrodes 301 and 302 face each other. In FIG. 13, 2 × 2 arrangement regions for arranging the rod-like structure light emitting elements are arranged, but any number may be arranged.

  FIG. 14 is a schematic sectional view taken along line XIV-XIV in FIG.

  First, as shown in FIG. 14, isopropyl alcohol (IPA) 311 including a rod-shaped structure light emitting element 310 is thinly applied on an insulating substrate 300. In addition to IPA 311, ethylene glycol, propylene glycol, methanol, ethanol, acetone, or a mixture thereof may be used. Alternatively, the IPA 311 can use a liquid made of another organic material, water, or the like.

  However, if a large current flows between the metal electrodes 301 and 302 through the liquid, a desired voltage difference cannot be applied between the metal electrodes 301 and 302. In such a case, the entire surface of the insulating substrate 300 may be coated with an insulating film of about 10 nm to 30 nm so as to cover the metal electrodes 301 and 302.

The thickness of applying the IPA 311 including the rod-shaped structure light emitting element 310 is such that the rod-shaped structure light emitting element 310 can move in the liquid so that the rod-shaped structure light emitting element 310 can be arranged in the next step of arranging the rod-shaped structure light emitting element 310. That's it. Therefore, the thickness of applying the IPA 311 is equal to or greater than the thickness of the rod-shaped structure light emitting element 310, and is, for example, several μm to several mm. If the applied thickness is too thin, the rod-like structure light emitting element 310 is difficult to move. If it is too thick, the time for drying the liquid becomes long. Further, the amount of the rod-like structure light emitting element 310 is preferably 1 × 10 ⁴ pieces / cm ³ to 1 × 10 ⁷ pieces / cm ³ with respect to the amount of IPA.

  In order to apply the IPA 311 including the rod-shaped structure light-emitting element 310, a frame is formed around the outer periphery of the metal electrode on which the rod-shaped structure light-emitting element 310 is arranged, and the IPA 311 including the rod-shaped structure light-emitting element 310 is formed in a desired thickness. It may be filled so that However, when the IPA 311 including the rod-shaped structure light emitting element 310 has viscosity, it can be applied to a desired thickness without requiring a frame.

  A liquid made of IPA, ethylene glycol, propylene glycol,..., Or a mixture thereof, or other organic substances, or a liquid such as water is desirable for the arrangement process of the rod-shaped structure light emitting element 310 to have a low viscosity, It is desirable that it evaporates easily when heated.

  Next, a potential difference is applied between the metal electrodes 301 and 302. In the ninth embodiment, a potential difference of 1V was appropriate. The potential difference between the metal electrodes 301 and 302 can be 0.1 to 10 V, but if the voltage is 0.1 V or less, the arrangement of the rod-shaped structure light emitting elements 310 is poor, and if it is 10 V or more, insulation between the metal electrodes becomes a problem. start. Therefore, it is preferably 1 to 5V, and more preferably about 1V.

  FIG. 15 shows the principle that the rod-shaped structure light emitting elements 310 are arranged on the metal electrodes 301 and 302. As shown in FIG. 15, when a potential VL is applied to the metal electrode 301 and a potential VR (VL <VR) is applied to the metal electrode 302, a negative charge is induced in the metal electrode 301 and a positive charge is applied to the metal electrode 302. Is induced. When the rod-shaped structure light emitting element 310 approaches, a positive charge is induced on the side close to the metal electrode 301 and a negative charge is induced on the side close to the metal electrode 302. The charge is induced in the rod-shaped structure light emitting element 310 by electrostatic induction. That is, the rod-shaped structure light emitting element 310 placed in the electric field is caused by the charge being induced on the surface until the internal electric field becomes zero. As a result, an attractive force is exerted between each electrode and the rod-shaped structure light emitting element 310 by an electrostatic force, and the rod-shaped structure light emitting element 310 follows the electric lines of force generated between the metal electrodes 301 and 302 and each rod-shaped structure light emitting element 310. Since the charges induced in the are substantially equal, the repulsive force caused by the charges causes the charges to be regularly arranged in a fixed direction at almost equal intervals. However, for example, in the rod-shaped structure light emitting device shown in FIG. 1-4 of the first embodiment, the direction of the exposed portion 13a side of the semiconductor core 13 covered with the semiconductor layer 14a is not constant, and becomes random (others The same applies to the rod-shaped structure light emitting device of the embodiment).

  As described above, an electric field generated between the metal electrodes 301 and 302 in the rod-shaped structure light emitting element 310 generates charges in the rod-shaped structure light emitting element 310, and the rod-shaped structure light emitting elements 310 are applied to the metal electrodes 301 and 302 by the attractive force of the charges. Therefore, the size of the rod-like structure light emitting element 310 needs to be a size that can move in the liquid. Therefore, the size of the rod-shaped structure light emitting element 310 varies depending on the application amount (thickness) of the liquid. When the amount of liquid applied is small, the rod-shaped structure light emitting element 310 must be nano-order size, but when the amount of liquid applied is large, it may be micro-order size.

  When the rod-shaped structure light-emitting element 310 is not electrically neutral and is charged positively or negatively, the rod-shaped structure light-emitting element 310 can be formed only by giving a static potential difference (DC) between the metal electrodes 301 and 302. It cannot be arranged stably. For example, when the rod-shaped structure light emitting element 310 is positively charged as a net, the attractive force with the metal electrode 302 in which the positive charge is induced becomes relatively weak. Therefore, the arrangement of the rod-shaped structure light emitting elements 310 is not targeted.

  In such a case, it is preferable to apply an AC voltage between the metal electrodes 301 and 302 as shown in FIG. In FIG. 16, a reference potential is applied to the metal electrode 302, and an AC voltage having an amplitude VPPL / 2 is applied to the metal electrode 301. By doing so, even when the rod-shaped structure light emitting element 310 is charged, the arrangement can be kept as a target. In this case, the frequency of the AC voltage applied to the metal electrode 302 is preferably 10 Hz to 1 MHz, and more preferably 50 Hz to 1 kHz because the arrangement is most stable. Furthermore, the AC voltage applied between the metal electrodes 301 and 302 is not limited to a sine wave, but may be any voltage that varies periodically, such as a rectangular wave, a triangular wave, and a sawtooth wave. VPPL was preferably about 1V.

  Next, after the rod-shaped structure light emitting elements 310 are arranged on the metal electrodes 301 and 302, the insulating substrate 300 is heated to evaporate the liquid and dry the metal. The wires are arranged at equal intervals along the lines of electric force between 302 and fixed.

  FIG. 17 is a plan view of an insulating substrate 300 on which the rod-shaped structure light emitting elements 310 are arranged. By using the insulating substrate 300 on which the rod-shaped structure light emitting elements 310 are arranged for a backlight of a liquid crystal display device or the like, it is possible to realize a backlight that can be reduced in thickness and weight, has high luminous efficiency, and saves power. it can. Further, by using the insulating substrate 300 in which the rod-shaped structure light emitting elements 310 are arranged as a lighting device, it is possible to realize a lighting device that can be reduced in thickness and weight, has high luminous efficiency, and saves power.

  FIG. 18 is a plan view of a display device using an insulating substrate on which the rod-shaped structure light emitting elements 310 are arranged. As shown in FIG. 18, the display device 400 includes a display portion 401, a logic circuit portion 402, a logic circuit portion 403, a logic circuit portion 404, and a logic circuit portion 405 on an insulating substrate 410. In the display portion 401, rod-shaped structure light emitting elements 310 are arranged in pixels arranged in a matrix.

  FIG. 19 is a circuit diagram of a main part of the display unit 401 of the display device 400. The display unit 401 of the display device 400 has a plurality of scanning signal lines GL (see FIG. 19) intersecting each other as shown in FIG. 19 shows only one line) and a plurality of data signal lines SL (only one line is shown in FIG. 19). Two adjacent scanning signal lines GL and two adjacent data signal lines SL are provided. Pixels are arranged in a matrix in a portion surrounded by. This pixel has a switching element Q1 having a gate connected to the scanning signal line GL and a source connected to the data signal line SL, a switching element Q2 having a gate connected to the drain of the switching element Q1, and the switching element Q2. And a plurality of light emitting diodes D1 to Dn (bar-shaped structure light emitting element 310) driven by the switching element Q2.

  The pn polarities of the rod-shaped structure light emitting elements 310 are not aligned on one side, but are randomly arranged. For this reason, at the time of driving, it is driven by an alternating voltage, and the bar-shaped structure light emitting elements 310 having different polarities emit light alternately.

  Further, according to the display device, by using the rod-shaped structure light emitting element, it is possible to realize a display device that can be reduced in thickness and weight, has high luminous efficiency, and saves power.

  In addition, according to the method for manufacturing the light emitting device, the backlight, the lighting device, and the display device, the insulating substrate 300 in which the array region is formed in units of two metal electrodes 301 and 302 to which independent potentials are respectively applied. The liquid containing the rod-shaped structure light emitting element 310 of nano order size or micro order size is applied on the insulating substrate 300. Thereafter, independent voltages are applied to the two metal electrodes 301 and 302, respectively, so that the fine rod-shaped light emitting elements 310 are arranged at positions defined by the two metal electrodes 301 and 302. Thereby, the rod-shaped structure light emitting element 310 can be easily arranged on the predetermined insulating substrate 300.

  Moreover, in the manufacturing method of the light emitting device, the backlight, the lighting device, and the display device, the light emitting device, the backlight, the lighting device, and the display device that can reduce the amount of semiconductors used and can be reduced in thickness and weight are manufactured. can do. In addition, the light emitting element 310 has a light emitting region that is widened by emitting light from the entire side surface of the semiconductor core covered with the semiconductor layer, so that the light emitting device, backlight, and illumination with high luminous efficiency and power saving can be obtained. A device and a display device can be realized.

  In the first to ninth embodiments, a semiconductor having GaN as a base material is used for the semiconductor core and the semiconductor layer. The present invention may be applied to a light emitting element using a semiconductor. Further, although the semiconductor core is n-type and the semiconductor layer is p-type, the present invention may be applied to a rod-shaped structure light-emitting element having a reverse conductivity type. Moreover, although the rod-shaped structure light emitting element having a rod-shaped semiconductor core with a circular cross section has been described, the present invention is not limited to this, and the bar may have an elliptical cross section, or a bar-shaped semiconductor having a polygonal cross section such as a hexagon. You may apply this invention to the rod-shaped structure light emitting element which has a core.

  In the first to ninth embodiments, the diameter of the rod-shaped structure light emitting element is 1 μm and the length is micro order size of 10 μm to 30 μm. However, at least the diameter or length of the nano order is less than 1 μm. A size element may be used. The diameter of the semiconductor core of the rod-shaped structure light emitting element is preferably 500 nm or more and 100 μm or less, and variation in the diameter of the semiconductor core can be suppressed as compared with the rod-shaped structure light emitting element of several tens nm to several hundred nm, and the light emission area, that is, the light emission characteristics. Variation can be reduced and yield can be improved.

  In the first to ninth embodiments, the semiconductor core and the cap layer are grown using the MOCVD apparatus. However, the semiconductor core and the cap layer are grown using another crystal growth apparatus such as an MBE (molecular beam epitaxial) apparatus. A cap layer may be formed.

  Although specific embodiments of the present invention have been described, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

10, 20, 30, 40, 50, 70, 90, 110 ... diaphragm part 11, 21, 31, 41, 51, 61, 71, 91, 111, 131 ... sapphire substrate 12, 22, 32, 42, 52, 52b, 62, 72, 92, 112, 132 ... growth masks 12a, 22a, 32a, 42a, 52a, 62a, 72a, 92a, 112a, 132a ... growth holes 13, 23, 33, 43, 53, 63, 81, 101, 121 ... Semiconductor cores 13a, 43a, 53a, 63a, 81a, 101a, 121a ... Exposed portions 13b, 43b, 53b, 63b, 81b, 101b, 121b ... Cover portions 13c, 23c, 33c, 43c, 53c, 81c, 101c, 121c ... tip portion 14, 14a, 44, 44a, 54, 54a, 64, 64a ... semiconductor layer 45, 66 ... semiconductor film 60, 130 ... constricted portion 65 ... groove portion 73 ... metal lift-off layer 74, 93, 113, 133 ... Resist pattern 76 ... Initial growth part 77, 97, 117 ... Touch Metal layer 82, 82a, 102, 1102a, 122, 122a ... MQW layer 83, 83a, 103, 103a, 123, 123a ... Quantum well layer 84, 84a, 104, 104a, 124, 124a ... Conductive layer 300 ... Insulating substrate 301, 302 ... Metal electrode 310 ... Light emitting element 311 ... IPA
400 ... Display device 401 ... Display unit 402, 403, 404, 405 ... Logic circuit unit 410 ... Insulating substrate

Claims (7)

A growth mask forming step of forming a growth mask having a growth hole for growing a rod-shaped first conductivity type semiconductor core inside on the substrate;
A semiconductor core forming step of forming the rod-shaped first conductivity type semiconductor core by crystal growth of the first conductivity type semiconductor on the exposed region of the substrate exposed by the growth hole of the growth mask;
A semiconductor layer forming step of forming a second conductivity type semiconductor layer so as to cover a covering portion which is a part of the semiconductor core;
A growth mask removing step of removing the growth mask by etching so as to expose an exposed portion which is another part of the semiconductor core after the semiconductor layer forming step;
A separation step of separating the semiconductor core including at least a part of the exposed portion and the covering portion from the substrate after the growth mask removing step;
In the growth mask forming step, a shape changing portion in which the shape of a cross section perpendicular to the axial direction of the growth hole is changed along the axial direction is formed on the inner peripheral side of the growth hole of the growth mask. A method of manufacturing a rod-shaped structure light emitting device, comprising forming a growth mask. In the manufacturing method of the rod-shaped structure light emitting element according to claim 1,
In the semiconductor core forming step, the first conductivity type semiconductor is crystal-grown on the exposed region of the substrate exposed by the growth hole of the growth mask so as to exceed the height of the growth hole of the growth mask. Forming a semiconductor core,
In the semiconductor layer forming step, the semiconductor layer is formed so as to cover the covered portion of the semiconductor core formed and exposed above the growth mask surface. In the manufacturing method of the rod-shaped structure light emitting element according to claim 1,
In the semiconductor core formation step, the semiconductor core is formed by crystal growth of a first conductivity type semiconductor on the exposed region of the substrate exposed by the growth hole of the growth mask and in the growth hole of the growth mask,
After the semiconductor core forming step and before the semiconductor layer forming step, an upper portion of the growth mask is removed by etching, and an exposure step is performed to expose the covering portion of the semiconductor core,
In the semiconductor layer forming step, the semiconductor layer is formed so as to cover the covered portion of the semiconductor core exposed in the exposing step. In the manufacturing method of the rod-shaped structure light emitting element as described in any one of Claim 1 to 3,
The substrate includes a substrate body and a first conductivity type semiconductor film on the substrate body,
In the growth mask formation step, a growth mask having the growth holes is formed on the semiconductor film of the substrate, and the method for manufacturing a rod-shaped structure light emitting element is characterized in that: In the manufacturing method of the rod-shaped structure light emitting element as described in any one of Claim 1 to 4,
A quantum well layer forming step of forming a quantum well layer so as to cover the surface of the semiconductor core after the semiconductor core forming step and before the semiconductor layer forming step;
In the next semiconductor core formation step, the semiconductor layer is formed so as to cover the surface of the quantum well layer. In the manufacturing method of the rod-shaped structure light emitting element as described in any one of Claim 1-5,
The shape change portion of the growth mask is an aperture portion formed on the inner peripheral side and substrate side of the growth hole so that the inner diameter decreases toward the substrate side, or the inner peripheral side of the growth hole And the manufacturing method of the rod-shaped structure light emitting element characterized by being the constriction part formed so that it may be constricted in the position spaced apart from the said board | substrate side by predetermined spacing. In the manufacturing method of the rod-shaped structure light emitting element as described in any one of Claim 1-6,
A catalyst metal layer forming step for forming a catalyst metal layer on the exposed region of the substrate exposed by the growth hole of the growth mask after the growth mask forming step and before the semiconductor core forming step;
In the next step of forming the semiconductor core, the semiconductor core is formed by crystal growth of the first conductivity type semiconductor from the interface between the catalytic metal layer and the substrate. Method.

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