Patent Publication Number: US-2015083992-A1

Title: Group-iii nitride semiconductor light emitting element, method of manufacturing the same and method of manufacturing mounting body

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Japanese Patent Application No. 2013-194999 (filed on Sep. 20, 2013), the entire contents of which are hereby incorporated by reference. 
     BACKGROUND 
     1. Technical Field 
     The invention relates to a group-III nitride semiconductor light emitting element having improved light extraction efficiency, a method of manufacturing the same and a method of manufacturing a mounting body. 
     2. Background Art 
     In recent years, in order to realize high brightness and high efficiency of a semiconductor light emitting element, it is needed to improve internal quantum efficiency and light extraction efficiency. As a cause of lowering the light extraction efficiency, total reflection of a part of light at an interface between a semiconductor layer and an outside air may be exemplified. When the light is directed from the semiconductor layer having a high refractive index into the outside having a low refractive index, the light of a threshold angle (θc) or larger is totally reflected at an element interface (refer to a paragraph [0003] of JP-A-2009-38407). 
     For this reason, JP-A-2012-33695 discloses a technology of forming a light extraction surface into an irregularity surface (refer to FIG. 6 and the like of JP-A-2012-33695). 
     Thereby, the light is not incident with the threshold angle (θc) or larger at the interface between the semiconductor layer and the outside air. 
     However, in order to manufacture a light emitting element having higher brightness, it is required to further improve the light extraction efficiency. 
     The invention has been made to solve the above problem of the related art. That is, an object of the invention is to provide a group-III nitride semiconductor light emitting element having improved light extraction efficiency from a light extraction surface, a method of manufacturing the same and a method of manufacturing a mounting body. 
     SUMMARY 
     (1) A method of manufacturing a group-III nitride semiconductor light emitting element includes a first irregularity shape part forming process of sequentially forming an n-type semiconductor layer, a light emitting layer and a p-type semiconductor layer on an irregularity substrate to make a laminated body and forming a first irregularity shape part on the n-type semiconductor layer, a first irregularity shape part exposing process of separating the irregularity substrate from the laminated body to expose the first irregularity shape part of the n-type semiconductor layer, and a second irregularity shape part forming process of roughening a surface of the first irregularity shape part of the n-type semiconductor layer to form a second irregularity shape part having fine irregularity on the first irregularity shape part. 
     In the method of manufacturing the group-III nitride semiconductor light emitting element, the first irregularity shape part and the fine irregularity shape formed on the surface of the first irregularity shape part are formed on the surface of the n-type semiconductor layer. Therefore, the light extraction efficiency of the semiconductor light emitting element manufactured by the method is sufficiently higher than the light extraction efficiency of the semiconductor light emitting element of the related art. In the meantime, the first irregularity shape part has a shape corresponding to irregularity of an irregularity substrate. The first irregularity shape part is formed on a side of the n-type semiconductor layer facing the irregularity substrate. 
     (2) In the method according to (1), the first irregularity shape part has a flat part and an inclined part, and the second irregularity shape part forming process includes forming fine irregularity on both the flat part and the inclined part. 
     (3) The method according to (1) or (2) further includes a fluorescent material containing glass layer forming process of forming a fluorescent material containing glass layer on the first irregularity shape part of the n-type semiconductor layer, and a third irregularity shape part forming process of roughening a surface of the fluorescent material containing glass layer to form a third irregularity shape part on the fluorescent material containing glass layer. 
     (4) In the method according to any one of (1) to (3), the second irregularity shape part forming process includes roughening the first irregularity shape part by wet etching. 
     (5) In the method according to (4), the second irregularity shape part farming process includes etching the first irregularity shape part by a TMAH solution or KOH solution. 
     (6) In the method according to any one of (1) to (5), the first irregularity shape part forming process includes forming a plurality of concave portions, which corresponds to a plurality of convex portions of a convex shape substrate, on the n-type semiconductor layer, and the first irregularity shape part exposing process includes exposing the multiple concave portions of the n-type semiconductor layer. 
     (7) In the method according to any one of (1) to (6), the first irregularity shape part exposing process includes removing the irregularity substrate by a laser liftoff method. 
     (8) The method according to any one of (1) to (7) further includes a cleaning process of cleaning the surface of the first irregularity shape part by an HCl solution, wherein the cleaning process is performed before the second irregularity shape part forming process. 
     (9) A method of manufacturing a mounting body of a group-III nitride light emitting element includes the first irregularity shape part forming process, the first irregularity shape part exposing process and the second irregularity shape part forming process according to any one of (1) to (8), and a mounting process of mounting the laminated body on a sub-mount to make a mounting body, wherein after the mounting process, the first irregularity shape part exposing process and the second irregularity shape part forming process are performed. 
     (10) A group-III nitride semiconductor light emitting element includes an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer. The n-type semiconductor layer includes a first irregularity shape part having a flat part and an inclined part, and the first irregularity shape part has a second fine irregularity shape part on both the flat part and the inclined part. 
     (11) In the group-III nitride semiconductor light emitting element according to (10), a fluorescent material containing glass layer is provided on the first irregularity shape part and the second irregularity shape part of the n-type semiconductor layer, and the fluorescent material containing glass layer has a third roughened irregularity shape part. 
     According to the invention, a group-III nitride semiconductor light emitting element having improved light extraction efficiency from a light extraction surface, a method of manufacturing the same and a method of manufacturing a mounting body are provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic configuration view showing a structure of a light emitting element according to a first illustrative embodiment. 
         FIG. 2  is an enlarged view of an n-type semiconductor layer and a periphery thereof according to the first illustrative embodiment. 
         FIG. 3  shows an irregularity shape of a growth substrate that is used for a method of manufacturing the light emitting element according to the first illustrative embodiment. 
         FIG. 4  shows a correspondence relation between the irregularity shape of the growth substrate that is used for the method of manufacturing the light emitting element according to the first illustrative embodiment and an irregularity shape of the n-type semiconductor layer. 
         FIG. 5  illustrates a method of manufacturing the light emitting element according to the first illustrative embodiment. 
         FIG. 6  illustrates the method of manufacturing the light emitting element according to the first illustrative embodiment. 
         FIG. 7  illustrates the method of manufacturing the light emitting element according to the first illustrative embodiment. 
         FIG. 8  illustrates the method of manufacturing the light emitting element according to the first illustrative embodiment. 
         FIG. 9  illustrates the method of manufacturing the light emitting element according to the first illustrative embodiment. 
         FIG. 10  is a schematic configuration view showing a structure of a light emitting element according to a modified embodiment of the first illustrative embodiment. 
         FIG. 11  is a schematic configuration view showing a structure of a light emitting element according to a second illustrative embodiment. 
         FIG. 12  illustrates a method of manufacturing the light emitting element according to the second illustrative embodiment. 
         FIG. 13  illustrates the method of manufacturing the light emitting element according to the second illustrative embodiment. 
         FIG. 14  illustrates the method of manufacturing the light emitting element according to the second illustrative embodiment. 
         FIG. 15  illustrates the method of manufacturing the light emitting element according to the second illustrative embodiment. 
         FIG. 16  is a schematic configuration view showing a structure of a light emitting element according to a third illustrative embodiment. 
         FIG. 17  illustrates a method of manufacturing the light emitting element according to the third illustrative embodiment. 
         FIG. 18  illustrates the method of manufacturing the light emitting element according to the third illustrative embodiment. 
         FIG. 19  is a graph showing a relation between treatment time of a TMAH solution and a total radiant flux in the light emitting elements of embodiments and a comparative example. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, specific illustrative embodiments of a semiconductor light emitting element will be described with reference to the drawings. However, the invention is not limited to the illustrative embodiments. Also, a laminated structure of respective layers and an electrode structure of a light emitting element that will be described later are just exemplary. In particular, a roughened surface is extremely shown. Also, a laminated structure different from the illustrative embodiments is also possible. In the respective drawings, a thickness of each layer is just conceptually shown. 
     First Illustrative Embodiment 
     1. Semiconductor Light Emitting Element 
     A group-III nitride semiconductor light emitting element of this illustrative embodiment is described.  FIG. 1  is a schematic configuration view showing a structure of a light emitting element  100  according to a first illustrative embodiment. The light emitting element  100  is a semiconductor light emitting element consists of a group-III nitride semiconductor. Also, the light emitting element  100  is formed by a laser liftoff method of removing a growth substrate with laser. For this reason, the growth substrate such as a sapphire substrate does not remain on the light emitting element  100 . A light extraction surface Z 1  exists at an n-type semiconductor layer  80 -side. 
     As shown in  FIG. 1 , the light emitting element  100  is formed by sequentially arranging a p-type electrode P 1 , a support substrate  10 , a first conductive metal layer  20 , a conductive bonding material layer  30 , a second conductive metal layer  40 , a conductive reflective film  50 , a p-type semiconductor layer  60 , a light emitting layer  70 , an n-type semiconductor layer  80  and an n-type electrode N 1  in corresponding order. 
     The p-type electrode P 1  has a Pt layer, a Ti layer, a Pt layer, a Ti layer and an Au layer, which are formed from the support substrate  10  in corresponding order. This is just exemplary and the other laminated structures are also possible. 
     The support substrate  10  is a support member for holding a shape of the light emitting element  100 . Also, the support substrate is to prevent deformation of the light emitting element  100  and to increase a mechanical strength of the light emitting element  100 . The support substrate  10  is made of Si. Alternatively, the support substrate may be made of GaAs, Ge and the other metal materials. After the light emitting element  100  is made, it is necessary to supply current to the light emitting layer. For this reason, the support substrate  10  is necessarily made of a conductive material. 
     The first conductive metal layer  20  is to improve adhesiveness of the support substrate  10  and the conductive bonding material layer  30 . The first conductive metal layer  20  may be made of Au, for example. 
     The conductive bonding material layer  30  is a layer including a bonding material for bonding a formed semiconductor layer and the support substrate  10  in a manufacturing process of the light emitting element  100 . After the light emitting element  100  is made, it is necessary to supply current to the light emitting layer. For this reason, the conductive bonding material layer  30  is necessarily made of a conductive material. Specifically, an AuSn-based soldering material may be used. The other soldering alloy is also possible. 
     The second conductive metal layer  40  is to improve adhesiveness the conductive bonding material layer  30  and the conductive reflective film  50 . The second conductive metal layer  40  also has a function of preventing the soldering material of the conductive bonding material layer  30  from diffusing into the semiconductor layer. The second conductive metal layer  40  may be made of Au, for example. 
     The conductive reflective film  50  is a film for reflecting light generated by the light emitting layer  70 . Also, the conductive reflective film  50  has conductivity. This is to enable the sufficient current to flow to the light emitting layer  70  of the light emitting element  100 . To this end, the conductive reflective film  50  has both reflectivity of reflecting light and conductivity enabling the current to flow. 
     The conductive reflective film  50  is made of Ag, Al or alloy including Al or Ag as a main component. Alternatively, rhodium (Rh), ruthenium (Ru), platinum (Pt) or alloy including at least one of the metals is also possible. Alternatively, a distributed Bragg reflective film formed by a plurality of layers of two materials having different refractive indexes is also possible. 
     The p-type semiconductor layer  60  is to trap electrons. That is, the p-type semiconductor layer  60  is to prevent the electrons from diffusing towards the conductive reflective film  50 . Thereby, it is possible to improve the light emitting efficiency in the light emitting layer  70 . 
     The light emitting layer  70  is a layer in which an electron and a hole are combined to emit the light. To this end, the light emitting layer  70  has a multi quantum well structure in which a well layer having a small band gap and a barrier layer having a large band gap are alternately formed. Here, the well layer is an InGaN layer and the barrier layer is an AlGaN layer. Also, the well layer may be a GaN layer and the barrier layer may be the AlGaN layer. Alternatively, the barrier layer may be an AlInGaN layer. Alternatively, the above layers may be freely combined to form a unit structure of four or more layers and the unit structure may be repeated. Also, a SQW layer may be used as the light emitting layer. The above is just exemplary and the other materials or structures are also possible. 
     The n-type semiconductor layer  80  is a contact layer that is contacted to the n-type electrode N 1  and is a layer for preventing stress from being applied to the light emitting layer  70 . Also, the n-type semiconductor layer  80  is to prevent In of the light emitting layer  70  from diffusing. An Si concentration thereof is 1×10 18 /cm 3  or larger. The details thereof will be described later. 
     The n-type electrode N 1  is formed on the n-type semiconductor layer  80 . That is, the n-type electrode N 1  and the n-type semiconductor layer  80  are conductively connected to each other. The n-type electrode N 1  is a metallic electrode and is not transparent in general. 
     2. Shape of n-Type Semiconductor Layer 
     2-1. First Irregularity Shape Part 
     The n-type semiconductor layer  80  has the light extraction surface Z 1 .  FIG. 2  is an enlarged view of the light extraction surface Z 1  and a periphery thereof of the light emitting element  100 . The n-type semiconductor layer  80  has a first irregularity shape part  81 . The first irregularity shape part  81  has a flat surface  81   a , an inclined surface  81   b  and a flat surface  81   c . Like this, the first irregularity shape part  81  has the flat part and the inclined surface. The n-type semiconductor layer  80  has a plurality of concave portions X 1 . The concave portion X 1  has the flat surface  81   c  that is a bottom surface and the inclined surface  81   b  surrounding the flat surface  81   c . The concave portion X 1  of the first irregularity shape part  81  is formed in correspondence to irregularity of the growth substrate, which will be described later. 
     The flat surface  81   a , the inclined surface  81   b  and the flat surface  81   c  have second irregularity shape parts  82 , respectively. The second irregularity shape parts  82  are formed resulting from roughening by a wet etching, which will be described later. That is, the first irregularity shape part  81  of the n-type semiconductor layer  80  has the second irregularity shape parts  82  of which the irregularity is fine. The flat part and the inclined surface of the first irregularity shape part  81  are formed with fine irregularities. 
     2-2. Light Emitting Efficiency 
     In this way, the light extraction surface Z 1  of the light emitting element  100  has the first irregularity shape part  81  and the second irregularity shape parts  82  that are the fine irregularity formed on the first irregularity shape part  81 . For this reason, the light generated from the light emitting layer  70  is little illuminated to the light extraction surface Z 1  at a large incident angle. Thus, the light is little totally reflected at a boundary surface between the n-type semiconductor layer  80  and the element outside. That is, the light extraction efficiency of the light emitting element  100  is improved, as compared to the light emitting element of the related art. A degree of the improvement will be described later. 
     Here, as shown in  FIG. 2 , a depth H 1  of the concave portion X 1  is 1 μm or larger and 2 μm or smaller. A pitch interval of the concave portion X 1  is 3 μm or larger and 5 μm or smaller, more preferably, 3 μm or larger and 4 μm or smaller. A width W 1  of the flat surface  81   c , which is a bottom surface of the concave portion X 1 , is 0 μm or larger and 0.5 μm or smaller, more preferably, 0.05 μm or larger and 0.3 μm or smaller. A width W 2  of an upper surface of the concave portion X 1  is 2 μm or larger and 4 μm or smaller, more preferably 2.7 μm or larger and 3.3 μm or smaller. An angle between the flat surface  81   c  and the inclined surface  81   b  is 45° or larger and 60° or smaller, more preferably 50° or larger and 60° or smaller. 
     3. Growth Substrate (Irregularity Substrate) 
     3-1. Shape of Growth Substrate 
       FIG. 3  shows a growth substrate that is used for a method of manufacturing the light emitting element of this illustrative embodiment. The sapphire substrate S 1  shown in  FIG. 3  is a growth substrate having an irregularity shape S 11  on a principal surface. Specifically, the irregularity shape S 11  has a plurality of convex portions S 11   a . The material of the growth substrate is not limited to sapphire. 
     3-2. Correspondence Relation Between Shape of Irregularity Substrate and Shape of n-Type Semiconductor Layer 
       FIG. 4  shows a correspondence relation between the shape of the sapphire substrate S 1  and the shape of the n-type semiconductor layer  80 . As shown in  FIG. 4 , the convex portion S 11   a  of the sapphire substrate S 1  and the concave portion X 1  of the n-type semiconductor layer  80  have shapes corresponding to each other. Therefore, the convex portion S 11   a  of the sapphire substrate S 1  can be concisely matched with the concave portion X 1  of the n-type semiconductor layer  80 . 
     However, as described later, since the sapphire substrate S 1  is removed from the n-type semiconductor layer  80  by using the laser liftoff method and the like, a damage is somewhat caused in the n-type semiconductor layer  80 . For this reason, actually, the convex portion S 11   a  of the sapphire substrate S 1  and the concave portion X 1  of the n-type semiconductor layer  80  have shapes slightly deviating from each other. 
     Accordingly, a height H 1   a  of the convex portion S 11   a  is substantially the same as the depth H 1  of the concave portion X 1 . A pitch interval  11   a  of the convex portion S 11   a  is substantially the same as the pitch interval I 1  of the concave portion X 1 . A width W 1   a  of an apex of the convex portion S 11   a  is substantially the same as the width W 1  of the flat surface  81   c  of the concave portion X 1 . A width W 2   a  of a bottom of the convex portion S 11   a  is substantially the same as the width W 2  of the upper surface of the concave portion X 1 . 
     4. Method of Manufacturing Semiconductor Light Emitting Element 
     In a method of manufacturing the semiconductor light emitting element of this illustrative embodiment, crystals of the respective layers are epitaxially grown by a metalorganic chemical vapor deposition (MOCVD) method. In the below, respective processes are described. 
     4-1. Semiconductor Layer Foal ing Process (First Irregularity Shape Part Forming Process) 
     In this illustrative embodiment, the sapphire substrate S 1  having the irregularity shape formed on the principal surface is used as the growth substrate. The sapphire substrate S 1  is put into a MODVD furnace. Then, the sapphire substrate S 1  is cleaned in a hydrogen gas, so that matters attached on the surface of the sapphire substrate S 1  are removed. Then, a low-temperature buffer layer B 1  is formed on the sapphire substrate S 1 . 
     Then, as shown in  FIG. 5 , the n-type semiconductor layer  80  is grown on the low-temperature buffer layer B 1 . Subsequently, the light emitting layer  70  is faulted on the n-type semiconductor layer  80 . Then, the p-type semiconductor layer  60  is formed on the light emitting layer  70 . Then, the conductive reflective film  50  is formed on the p-type semiconductor layer  60 . In the meantime, when growing the n-type semiconductor layer  80 , the first irregularity shape part  81  is fainted. 
     4-2. Bonding Layer Forming Process 
     Then, as shown in  FIG. 6 , the second conductive metal layer  40  and a low-melting point metal layer  32  are formed in corresponding order on the conductive reflective film  50 . In the meantime, the first conductive metal layer  20  and a low-melting point metal layer  31  are formed in corresponding order on the support substrate  10 . The low-melting point metal layer  31  formed at the support substrate  10 -side and the low-melting point metal layer  32  formed at the sapphire substrate S 1 -side are made to confront each other. Then, the low-melting point metal layer  31  and the low-melting point metal layer  32  are bonded. Here, the low-melting point metal layers  31 ,  32  are soldering materials. Then, the low-melting point metal layers  31 ,  32  become the integrated conductive bonding material layer  30 . Thereby, a laminated body D 1  as shown in  FIG. 7  is obtained. 
     4-3. Growth Substrate Separating Process (First Irregularity Shape Part Exposing Process) 
     Subsequently, the laser is illuminated to the principal surface of the sapphire substrate S 1  of the laminated body D 1  shown in  FIG. 7 . The laser that is here illuminated is KrF high-power pulse laser having a wavelength of 248 nm. Also, any of YAG laser (355 nm, 266 nm), XeCl laser (308 nm), ArF laser (155 nm) and the like may be used. The other laser is also used as long as it has a wavelength shorter than 365 nm. 
     Thereby, the sapphire substrate S 1  can be separated from the laminated body D 1  of  FIG. 7 . By this separation, the first irregularity shape part  81  of the n-type semiconductor layer  80  is exposed. Thereby, a laminated body D 2  of  FIG. 8  is manufactured. As shown in  FIG. 8 , at this stage, a plurality of concave portions X 1  is exposed. In the meantime, the low-temperature buffer layer B 1  is thin. Therefore, at least a part of the low-temperature buffer layer B 1  is removed together with the sapphire substrate S 1  by the growth substrate separating process. 
     As shown in  FIG. 8 , at this stage, the first irregularity shape part  81  is formed on the surface of the n-type semiconductor layer  80 . As described above, the first irregularity shape part  81  corresponds to the irregularity shape S 11  of the sapphire substrate S 1 . However, at this stage, the second irregularity shape part  82  having fine irregularity is not formed yet. 
     4-4. Cleaning Process 
     Then, the surface of the first irregularity shape part  81  of the n-type semiconductor layer  80  is cleaned. Specifically, an HCl aqueous solution is used. A concentration of the aqueous solution is 17% or larger and 34% or smaller. Thereby, the low-temperature buffer layer B 1 , which has not been removed by the laser, is removed. 
     4-5. Etching Process (Second Irregularity Shape Part Forming Process) 
     Subsequently, the first irregularity shape part  81  of the n-type semiconductor layer  80  is formed with the second irregularity shape parts  82  having fine irregularity. To this end, the surface of the first irregularity shape part  81  is roughened by wet etching. Specifically, the surface of the n-type semiconductor layer  80  is immersed into a TMAH solution. A temperature of the TMAH solution is within a range of 20° C. or higher and 80° C. or lower. The temperature of the TMAH solution is preferably 60° C. A concentration of the TMAH solution is within a range of 20% or higher and 60% or lower. The etching time is preferably 3 minutes or longer, as described later. By the etching, the second irregularity shape parts  82  are formed. Instead of the TMAH solution, a potassium hydroxide (KOH) aqueous solution may be used. A laminated body D 3  after the fine irregularity is formed is shown in  FIG. 9 . As shown in  FIG. 9 , the first irregularity shape part  81  has the second irregularity shape parts  82 . 
     4-6. Electrode Forming Process 
     Subsequently, the p-type electrode P 1  is formed on a surface of the support substrate  10 , which is opposite to the first conductive metal layer  20 . As the p-type electrode P 1 , a Pt layer, a Ti layer, a Pt layer, a Ti layer and an Au layer are formed in corresponding order from the support substrate  10 . Also, the n-type electrode N 1  is formed on the n-type semiconductor layer  80 . As the n-type electrode N 1 , a W layer, a Ti layer and an Au layer are formed in corresponding order from the n-type semiconductor layer  80 . By the above processes, the light emitting element  100  shown in  FIG. 1  is manufactured. 
     5. Modified Embodiments 
     5-1. Protective Film 
     In this illustrative embodiment, the n-type semiconductor layer  80  is exposed. However, a protective film that covers the first irregularity shape part  81  of the n-type semiconductor layer  80  may be formed. To this end, a sputter apparatus may be used. The protective film is transparent. As the protective film, SiO 2  may be used. SiO 2  is a dielectric material. Also, as the protective film, Si 3 N 4  or SiO 2X N 4Y  (X+3Y=1) may be used. Also, the protective film has an irregularity shape corresponding to the first irregularity shape part  81 . However, an inclination of an inclined surface of the protective film is slightly gentler, as compared to the first irregularity shape part  81 . 
     5-2. Conductive Protective Film 
     Furthermore, the protective film is preferably made of a conductive material. This is to enable the current to diffuse in a plane direction (a horizontal direction in  FIG. 1 ) of the semiconductor layer, thereby effectively supplying the current over a light emitting area of the light emitting layer. In this case, since the protective film is conductive, the n-type electrode N 1  is preferably formed on the protective film. By doing so, most of the first irregularity shape part  81  of the n-type semiconductor layer  80  is covered as much as possible, so that the current diffuses into the light emitting layer  70  in the plane direction. Here, as the conductive transparent material, indium tin oxide (ITO) may be used. Alternatively, ICO, IZO, ZnO, TiO 2 , NbTiO 2 , TaTiO 2  or the like may be used. 
     5-3. Substrate Peeling-off Method 
     In this illustrative embodiment, the sapphire substrate S 1  that is the growth substrate is removed from the semiconductor layer by the laser liftoff method. However, instead of using the laser, the etching may be used to peel off the sapphire substrate S 1  from the n-type semiconductor layer  80  of the laminated body D 1 . Also in this case, the sapphire substrate S 1  can be removed. The other known methods may be also used to remove the sapphire substrate S 1 . 
     5-4. Etching Process (Second Irregularity Shape Part Forming Process) 
     In this illustrative embodiment, the second irregularity shape parts  82  as shown  FIG. 2  and the like are formed by the fine irregularity forming process. In  FIG. 2 , the second irregularity shape part  82  is shown as a convex shape. However, as shown in  FIG. 10 , a light emitting element  150  having a concave shape is also possible. That is, a first irregularity shape part  181  has second irregularity shape parts  182 . The second irregularity shape parts  182  are concave portions. 
     5-5. Conductive Transparent Film 
     Also, a conductive transparent film may be formed between the p-type semiconductor layer  60  and the conductive reflective film  50 . The conductive transparent film is made of ITO, IZO or the like. The conductive transparent film is a layer for ohmic contact with the p-type semiconductor layer  60 . 
     5-6. Cleaning Process 
     In this illustrative embodiment, the cleaning process is performed. However, the cleaning process may be omitted. 
     6. Summary of First Illustrative Embodiment 
     As specifically described above, the light emitting element  100  of this illustrative embodiment is formed with the first irregularity shape part  81  corresponding to the irregularity of the growth substrate, and the first irregularity shape part is formed with the second fine irregularity shape parts  82 . For this reason, the light extraction efficiency of the light emitting element  100  is high. 
     In the meantime, this illustrative embodiment is just exemplary and is not construed to limit the invention. Therefore, the invention can be variously improved and modified without departing from the gist thereof. The laminated structure of the laminated body is not limited to the structure shown in the drawings. The laminated structure, the repeating number of times of the respective layers and the like may be arbitrarily selected. Also, the invention is not limited to the metalorganic chemical vapor deposition (MOCVD) method. The other crystal growth methods may be also used. 
     Second Illustrative Embodiment 
     1. Semiconductor Light Emitting Element 
     A second illustrative embodiment is described. A light emitting element  200  of this illustrative embodiment is manufactured by the laser liftoff method. As shown in  FIG. 11 , the light emitting element  200  has a support substrate  210 , an n-type electrode N 2 , a soldering bonding layer  222 , a metal layer  230 , a p-type electrode P 2 , a soldering bonding layer  221 , a reflective layer  240 , a transparent electrode layer  250 , a p-type semiconductor layer  260 , a light emitting layer  270 , an n-type semiconductor layer  280  and a fluorescent material containing glass layer  290 . 
     Here, the soldering bonding layer  221  is to soldering-bond the p-type electrode P 2  and the reflective layer  240 . The soldering bonding layer  222  is to soldering-bond the n-type electrode N 2  and the metal layer  230 . Here, a refractive index of the fluorescent material containing glass layer  290  is about 1.3 to 2.1. In order to form the fluorescent material containing glass layer  290 , a CVD method, a sputtering method, a heating process and the like may be used. 
     The reflective layer  240  may be made of the same material as the conductive reflective film  50  of the first illustrative embodiment. The transparent electrode layer  250  may be made of the same material as the conductive transparent film described in the modified embodiment of the first illustrative embodiment. These are just exemplary and the other materials can be also used. 
     2. Fluorescent Material Containing Glass Layer 
     In this illustrative embodiment, the n-type semiconductor layer  280  has a first irregularity shape part  281 . The first irregularity shape part  281  has a plurality of concave portions X 2 . The concave portion X 2  is substantially the same as the concave portion X 1  of the n-type semiconductor layer  80  of the light emitting element  100  of the first illustrative embodiment. That is, the concave portion X 2  has a plurality of fine irregularity shapes. That is, the first irregularity shape part  281  has second irregularity shape parts  282  of which irregularity is fine. 
     The fluorescent material containing glass layer  290  is formed on the first irregularity shape part  281  and the second irregularity shape parts  282 . A surface of the fluorescent material containing glass layer  290  is a third roughened irregularity shape part. The third irregularity shape part, i.e., the surface of the fluorescent material containing glass layer  290  is a light extraction surface Z 2  of the light emitting element  200 . In the light emitting element  200 , the n-type semiconductor layer  280  is contacted to the fluorescent material containing glass layer  290 . For this reason, a refractive index of the n-type semiconductor layer  280  is about 2.5. A refractive index of the fluorescent material containing glass layer  290  is sufficiently larger than 1. Thus, a difference between the refractive indexes of the n-type semiconductor layer  280  and the fluorescent material containing glass layer  290  is smaller than a difference between the refractive indexes of the n-type semiconductor layer  280  and the outside air. Therefore, as described later, the light emitting efficiency is improved. 
     3. Method of Manufacturing Semiconductor Light Emitting Element 
     3-1. Semiconductor Layer Forming Process (First irregularity Shape Part Forming Process) 
     Here, a method of manufacturing the light emitting element  200  is described. First, as shown in  FIG. 12 , the n-type semiconductor layer  280 , the light emitting layer  270  and the p-type semiconductor layer  260  are formed in corresponding order on a sapphire substrate S 2  having an irregularity shape. Then, a non-through hole is formed from the p-type semiconductor layer  260  to the n-type semiconductor layer  280 , so that a part of the n-type semiconductor layer  280  is exposed. Then, the metal layer  230  is formed on the exposed n-type semiconductor layer  280 . In the meantime, the transparent electrode layer  250  is formed on the p-type semiconductor layer  260 . The reflective layer  240  is formed on the transparent electrode layer  250 . 
     3-2. Bonding Process 
     Subsequently, as shown in  FIG. 13 , a laminated body having the p-type electrode P 2  and n-type electrode N 2  formed on the support substrate  210  and a laminated body having a semiconductor layer formed thereto are soldering-bonded. Thereby, the p-type electrode P 2  is bonded to the reflective layer  240  through the soldering bonding layer  221 . Also, the n-type electrode N 2  is bonded to the metal layer  230  through the soldering bonding layer  222 . 
     3-3. Growth Substrate Separating Process (First irregularity Shape Part Exposing Process) 
     Subsequently, the sapphire substrate S 2  is removed from the laminated body by the laser liftoff method. An aspect after the sapphire substrate S 2  is removed is shown in  FIG. 14 . As shown in  FIG. 14 , the n-type semiconductor layer  280  has the first irregularity shape part  281  on the surface thereof. The first irregularity shape part  281  has a shape corresponding to the irregularity shape of the sapphire substrate S 2 . 
     3-4. Etching Process (Second irregularity Shape Part Forming Process) 
     Then, the surface of the first irregularity shape part  281  is roughened. Thereby, the first irregularity shape part  281  is further formed with the second irregularity shape parts  282  that are the fine irregularity. The laminated body after this process is shown in  FIG. 15 . The first irregularity shape part  281  has the second irregularity shape parts  282  of which irregularity is fine. 
     3-5. Fluorescent Material Containing Glass Layer Forming Process 
     Then, the fluorescent material containing glass layer  290  is formed on the first irregularity shape part  281  of the n-type semiconductor layer  280 . The fluorescent material containing glass layer  290  contains therein a fluorescent material. 
     3-6. Roughening Process (Third Irregularity Shape Part Forming Process) 
     Subsequently, the surface of the fluorescent material containing glass layer  290  is roughened by the etching. The surface may be also roughened by a transfer or harsh grinding. Thereby, the surface of the fluorescent material containing glass layer  290  is roughened. Thereby, the surface of the fluorescent material containing glass layer  290  is formed with the third irregularity shape part. The third irregularity shape part is the light extraction surface Z 2 . 
     4. Modified Embodiments 
     The modified embodiments described in the first illustrative embodiment may be used. 
     5. Summary of Second Illustrative Embodiment 
     As specifically described above, the light emitting element  200  of this illustrative embodiment is formed with the first irregularity shape part  281  corresponding to the irregularity of the growth substrate, and the first irregularity shape part  281  is formed with the second fine irregularity shape parts  282 . For this reason, the light extraction efficiency from the semiconductor layer is high. Also, the fluorescent material containing glass layer  290  is formed on the second fine irregularity shape parts  282 . Therefore, white light is extracted from the light emitting element  200  and the light efficiency of the light emitting element  200  is high. 
     Third Illustrative Embodiment 
     1. Mounting Body 
     A third illustrative embodiment is described. In a mounting body  1300  of this illustrative embodiment, a light emitting element  300  is mounted on a sub-mount  1320 . As shown in  FIG. 16 , the mounting body  1300  has the light emitting element  300 , the sub-mount  1320 , a resin layer  1330  and a resin layer  1340 . The light emitting element  300  has a light extraction surface Z 3  at the n-type semiconductor layer-side. 
     2. Method of Manufacturing Mounting Body 
     In this illustrative embodiment, after the light emitting element  300  is mounted on the sub-mount  1320 , a surface of the n-type semiconductor layer is roughened. 
     2-1. Element Manufacturing Process (First Irregularity Shape Part Forming Process) 
     First, a light emitting element  350  shown in  FIG. 17  is manufactured. To this end, a semiconductor layer, a p-type electrode P 3  and an n-type electrode N 3  are formed on a sapphire substrate S 3 . The sapphire substrate S 3  is formed with the irregularity shape. Then, a plurality of elements faulted on a wafer is separated. Thereby, the light emitting element  350  is prepared. In the meantime, at this stage, a surface of the n-type semiconductor layer of the light emitting element  350  is not roughed yet. 
     2-2. Mounting Process 
     Subsequently, the light emitting element  350  is mounted on the sub-mount  1320 . The sub-mount  1320  has the resin layer  1340 . An underfill material is injected between the sub-mount  1320  and the light emitting element  350 . The underfill material is cured after predetermined time. Then, the underfill material becomes the resin layer  1330 . Thereby, a mounting body  1310  of  FIG. 18  is manufactured. 
     2-3. Growth Substrate Separating Process (First Irregularity Shape Part Exposing Process) 
     After the mounting process, the sapphire substrate S 3  is removed from the mounting body  1310 . To this end, the laser liftoff method is preferably used. Thereby, a first irregularity shape part  381  of the n-type semiconductor layer is exposed. 
     2-4. Cleaning Process 
     Subsequently, the first irregularity shape part  381  of the n-type semiconductor layer is cleaned using the HCl aqueous solution. 
     2-5. Etching Process (Second Irregularity Shape Part Forming Process) 
     Subsequently, the exposed first irregularity shape part  381  of the n-type semiconductor layer is etched. To this end, the TMAH solution is preferably used. Also, the KOH solution may be used. Thereby, the first irregularity shape part  381  is formed with fine irregularity. Thus, after this process, the first irregularity shape part  381  has second irregularity shape parts  382  of which irregularity is fine. By the above processes, the mounting body  1300  is manufactured. 
     3. Modified Embodiments 
     The modified embodiments described in the first illustrative embodiment may be used. Also, like the second illustrative embodiment, a fluorescent material containing glass layer may be formed on the first irregularity shape part  381  of the n-type semiconductor layer. 
     4 Summary of Third Illustrative Embodiment 
     As specifically described above, the light emitting element  300  of this illustrative embodiment is mounted on the sub-mount  1320 . The light emitting element  300  is formed with the first irregularity shape part  381  corresponding to the irregularity of the growth substrate, and the first irregularity shape part  381  is formed with the second fine irregularity shape parts  382 . Also, the light emitting element  300  is roughened on the light extraction surface thereof after it is mounted on the sub-mount  1320 . Therefore, the light extraction efficiency from the semiconductor layer is high. 
     Embodiments 
     1. Growth Substrate (Irregularity Substrate) 
     Here, an embodiment is described. In this illustrative embodiment, an irregularity substrate on which a plurality of convex shapes is repeatedly arranged was used. The substrate was made of sapphire. As shown in  FIG. 3 , the pitch interval I 1   a  was 4 μm. A diameter W 1   a  of the apex of the convex portion was 0.2 μm. A diameter W 2   a  of the base of the convex portion was 3 μm. A height H 1   a  of the convex portion was 1.5 μm. An angle θa between the principal surface of the substrate and the maximum inclined surface of the convex portion was 47°. 
     2. Sample Manufacturing 
     A buffer layer, an n-type semiconductor layer, a light emitting layer and a p-type semiconductor layer were formed in corresponding order on the sapphire substrate. Then, the laminated body having the semiconductor layer deposited thereto and the support substrate were soldering-bonded. After that, the sapphire substrate was separated from the laminated body. Then, the surface of the exposed n-type semiconductor layer was cleaned with the HCl aqueous solution and the n-type semiconductor layer was then etched with the TMAH solution. Also, a p-type electrode and an n-type electrode were formed. 
     In the meantime, a sample (an embodiment 1) having no fluorescent material containing glass layer and samples (embodiments 2 and 3) having a fluorescent material containing glass layer were manufactured. Also, for comparison, a sample (a comparative example 1) in which the n-type semiconductor layer is not provided with the fine irregularity was manufactured. 
     3. Test Result 
     3-1. A Case Where No Fluorescent Material Containing Glass Layer Was Formed 
     A test result is shown in  FIG. 19 . In  FIG. 19 , a horizontal axis indicates time for which the light emitting element was immersed into the TMAH solution and a vertical axis indicates a total radiant flux. Here, the total radiant flux of the light emitting element that has not been immersed into the TMAH solution yet was set to be 100%. That is, the total radiant flux of the light emitting element in which the irregularity corresponding to the irregularity shape of the irregularity substrate was formed but the fine irregularity was not formed was set to be 100%. 
     As shown in  FIG. 19 , the total radiant flux of the light emitting element was increased over the immersion time in the TMAH solution. When three minutes has elapsed, the value of the total radiant flux of the light emitting element was saturated. That is, it is possible to implement the sufficient fine processing by immersing the light emitting element in the TMAH solution for three minutes or longer. As shown in  FIG. 19 , the total radiant flux of the light emitting element was improved by about 13% when the immersion time in the TMAH solution was three minutes or longer and ten minutes or shorter. 
     3-2. A Case Where Fluorescent Material Containing Glass Layer Was Formed 
     Also, a case where the fluorescent material containing glass layer was formed is shown in  FIG. 19 . As shown in  FIG. 19 , the value of the total radiant flux was larger in the light emitting element having the fluorescent material containing glass layer. A table  1  summarizes the above results. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                   
                   
                 total 
               
               
                   
                   
                   
                   
                 radiant 
               
               
                   
                 fine processing 
                 glass layer 
                 refractive index 
                 flux 
               
               
                   
               
             
            
               
                 embodiment 1 
                 Yes 
                 No 
                 — 
                 113% 
               
               
                 embodiment 2 
                 Yes 
                 Yes 
                 1.57 
                 122% 
               
               
                 embodiment 3 
                 Yes 
                 Yes 
                 1.41 
                 120% 
               
               
                 comparative 
                 No 
                 No 
                 — 
                 100% 
               
               
                 example 1 
               
               
                   
               
            
           
         
       
     
     The embodiment 1 corresponds to the first illustrative embodiment. The light emitting element of the embodiment 1 was subject to the fine processing but was not formed with the fluorescent material containing glass layer. The total radiant flux of the embodiment 1 was 113%. 
     The embodiment 2 corresponds to the second illustrative embodiment. The light emitting element of the embodiment 2 was subject to the fine processing and was formed with the fluorescent material containing glass layer. The refractive index of the fluorescent material containing glass layer was 1.57. The total radiant flux of the embodiment 2 was 122%. 
     The embodiment 3 was substantially the same as the embodiment 2. However, the embodiment 3 was different from the embodiment 2 as regards the refractive index. The refractive index of the fluorescent material containing glass layer was 1.41. The total radiant flux of the embodiment 3 was 120%. 
     The comparative example 1 was not subject to the fine processing and was not formed with the fluorescent material containing glass layer. The total radiant flux of the comparative example 1 was 100%.