JP3938337B2 - Semiconductor light emitting device and manufacturing method thereof - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a semiconductor light emitting device and a method for manufacturing the same, and more particularly to a semiconductor light emitting device configured by additionally attaching a submount member to an element body for performing a light emitting action and a method for manufacturing the same.
[0002]
[Prior art]
In recent years, by using metalorganic chemical vapor deposition (hereinafter referred to as MOCVD method), a crystal of a gallium nitride compound semiconductor is grown on a sapphire substrate. Semiconductor light emitting devices have been developed.
[0003]
As shown in FIG. 9, the high-luminance blue light-emitting semiconductor light-emitting device has a GaN buffer layer 71 grown on a transparent sapphire substrate 70, and an N-type semiconductor layer 72 ( A GaN layer, an AlGaN layer), a light emitting layer 73 (InGaN layer), and a P-type semiconductor layer 74 (AlGaN layer, GaN layer) are grown in a laminated form. An N-side electrode 75 and a P-side electrode 76 are formed on the GaN layer in the N-type semiconductor layer 72 and the GaN layer in the P-type semiconductor layer 74, respectively.
[0004]
On the other hand, in the mounting structure of the semiconductor light emitting element to the lead frame 77 of the illustrated example which is a mounted member, both the N side electrode 75 and the P side electrode 76 are connected to the N side of the lead frame 77 using wires 78 and 79. The terminal portion 77a and the P-side terminal portion 77b are bonded to each other. The semiconductor light emitting element attached in this way is configured to emit light from the surface on the side where the electrode 76 is disposed, as indicated by an arrow in FIG.
[0005]
[Problems to be solved by the invention]
By the way, the conventional semiconductor light emitting element needs to be wire-bonded at two places on a mounted member such as a lead frame, and the number of steps for mounting or connecting is increased. The reality is that it has been forced to become complicated and complicated.
[0006]
In addition, since this type of semiconductor light emitting element emits light from the electrode mounting surface side, an electrode 76 exists in the light emitting region A as shown in FIG. The arrangement location is a non-light emitting portion. Therefore, the substantial light emitting region is narrowed by an amount corresponding to the electrode 76, and in the example shown in the drawing, the substantial light emitting region occupying the entire element is 1/2 or less of the total surface area. As a result, a sufficient amount of light emission cannot be obtained in spite of having the high luminance characteristics as described above, and it becomes difficult to meet the demand for high brightness when used for various display boards. Has the problem.
[0007]
The invention of the present application has been conceived under the above circumstances, and the number of wire bondings to a mounted member of a semiconductor light-emitting element can be reduced so that the connection work can be easily performed, and a semiconductor It is an object of the present invention to increase a substantial light-emitting region in a light-emitting element as much as possible to secure a sufficient light emission amount and improve brightness.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention takes the following technical means.
[0009]
That is, according to the first aspect of the present invention, an N-type semiconductor layer, a light emitting layer, and a P-type semiconductor layer are formed on the surface of a transparent sapphire substrate, and a P-side electrode is formed on the surface of the P-type semiconductor layer. And an element main body formed by forming an N-side electrode on the exposed surface portion of the N-type semiconductor layer, and an N-side electrode formed so as to be insulated from the surface of the conductive substrate. And an auxiliary N-side electrode layer that is formed directly and planarly so as to be conductive with respect to the surface of the conductive substrate and that has an auxiliary P-side electrode layer that faces the P-side electrode. A mounting member, arranged so that the surface sides of both the submount member and the element body face each other, and between the auxiliary N-side electrode layer and the N-side electrode, and the auxiliary P-side electrode layer and P-side power The auxiliary P-side electrode layer reflects light emitted from the light emitting layer of the element body by integrating the submount member and the element body so that each of the submount member and the element body is in a conductive state. and it functions as a surface, is characterized in that as light is emitted from the back side of the transparent sapphire substrate.
[0011]
On the other hand, the invention described in claim 2 of the present application is a method for manufacturing a semiconductor light emitting device according to claim 1, in which the element body and the submount member are separately manufactured, and then the element body. The auxiliary N-side electrode layer and the N-side electrode, and the auxiliary P-side electrode layer and the P-side electrode are directly connected to each other in a state where the surface side and the surface side of the submount member are opposed to each other. It is characterized by being glued.
[0013]
Operation and effect of the invention
The semiconductor light-emitting device according to the first aspect is integrated with the device main body mounted on the submount. Therefore, this semiconductor light emitting device can be easily mounted by bonding a submount member of the semiconductor light emitting device to a lead frame or the like.
[0014]
Further, light emission from the element body is performed from the back surface of the sapphire substrate, which is the surface opposite to the surface on which both electrodes are disposed, and the P-side electrode does not hinder light emission as in the conventional case. . Thereby, most of the back surface of the sapphire substrate becomes a substantial light emitting region, and a sufficient amount of light emission can be secured, and it is possible to meet a demand for high brightness when using this type of semiconductor light emitting element.
[0015]
Further, light emitted to the submount member side from the light-emitting layer of the device body, so it will be reflected by the auxiliary electrode layer of the surface of the submount member, from the rear surface of the sapphire board in the device body The total light emission amount further increases including the above reflected light, and higher brightness can be obtained.
[0017]
On the other hand, according to the invention described in claim 2 , after the element body and the submount member are separately manufactured, both the auxiliary electrodes and the electrodes are bonded to each other with the surface sides facing each other. Thus, the semiconductor light-emitting device described in claim 1 is obtained. According to such a method, mass production is promoted at the stage where both of the above are separately manufactured, and the manufacturing is performed despite the addition of a submount member which is a new component to this type of semiconductor light emitting device. Work complexity is effectively avoided.
[0019]
[Explanation of Examples]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
[0020]
1 is a schematic longitudinal front view showing an element body which is a component of a semiconductor light emitting element according to a first embodiment of the present invention, FIG. 2 is a schematic plan view thereof, and FIG. 3 is a sub view which is a component of the semiconductor light emitting element. FIG. 4 is a schematic plan view showing the mount member, FIG. 4 is a schematic plan view thereof, and FIG. 5 is a schematic vertical cross-sectional view showing the overall configuration of the semiconductor light emitting device and the state of attachment to the lead frame.
[0021]
As shown in FIG. 1, the element body 2 of the semiconductor light emitting element 1 according to the first embodiment basically includes an N-type semiconductor layer 4 and a light emitting layer on a sapphire substrate 3 which is a transparent insulating substrate. 5 and a P-type semiconductor layer 6 are formed. More specifically, the stacked unit 7 grows a gallium nitride (GaN) buffer layer 8 on the surface of a transparent or semi-transparent sapphire substrate 3, and an N-type GaN layer sequentially from the lower layer portion on the surface side. 41, an N-type Al _0.2 Ga _0.8 N layer 42, an In _0.15 Ga _0.85 N layer 5 as a light emitting layer, a P-type Al _0.2 Ga _0.8 N layer 61, and a P-type GaN layer 62. Formed. The light emitting layer 5 emits light having a wavelength corresponding to blue (preferably 470 nm).
[0022]
In addition, Si is added to the N-type GaN layer 41 and the N-type Al _0.2 Ga _0.8 N layer 42, and the P-type Al _0.2 Ga _0.8 N layer 61 and the P-type GaN layer 62 include Mg. In addition, Zn is added to the In _0.15 Ga _0.85 N layer 5. Then, the case of increasing the composition ratio Ga of In in the layer 5 of the In _0.15 Ga _0.85 N (the composition ratio), together with the wavelength of light emitted from the layer 5 is increased, the amount of the Zn When the ratio is increased, the wavelength of light becomes longer than when the composition ratio is increased. In addition, the thickness of each said layer is set to 3 micrometers, 300 nm, 50 nm, 300 nm, 150 nm in order of each layer 41, 42, 5, 61, 62 from the lower layer side, for example.
[0023]
The element body 2 in the illustrated example is a square shape finally obtained as a single chip, for example, having a square shape with a side of 0.5 mm in plan view. However, in actual manufacturing, the structure of the illustrated example is formed by MOCVD. Can be obtained by dividing the wafer into a single chip by dicing.
[0024]
An N-side electrode 9 is formed on the exposed surface portion removed by etching of the GaN layer 41 in the N-type semiconductor layer 4, and a P-side electrode 10 is formed on the surface portion of the GaN layer in the P-type semiconductor layer 6. . The N-side electrode 9 and the P-side electrode 10 are generally arranged in a plan view as shown in FIG.
[0025]
On the other hand, as shown in FIG. 3, the submount member 11 of the semiconductor light emitting device 1 according to the first embodiment has an insulating oxide film 13 made of SiO ₂ formed on the surface of an opaque conductive silicon substrate 12. The auxiliary P-side electrode layer 14 is formed by removing the central portion by etching, and the auxiliary N-side electrode layer 15 is formed on the surface portion of the oxide film 13 on the outer peripheral side. Both the auxiliary electrode layers 14 and 15 are formed by vapor deposition using an alloy of Au and Sn or an indium-based alloy. As will be described later, both the electrode and the solder metal are used. .
[0026]
The auxiliary P-side electrode layer 14 and the auxiliary N-side electrode layer 15 are roughly arranged in a plan view as shown in FIG. In addition, as shown in the figure, a band-shaped auxiliary N-side electrode layer 15 a that is electrically connected to two auxiliary N-side electrode layers 15 is provided on one side of the silicon substrate 12. It is formed in the part.
[0027]
Next, a method for manufacturing the semiconductor light emitting device 1 by joining and integrating the device body 2 and the submount member 11 having the above configuration, and the configuration of the semiconductor light emitting device 1 obtained thereby will be described.
[0028]
First, after the element body 2 and the submount member 11 are separately manufactured, the surface sides of the two are opposed to each other, and the N-side electrode 9 and the P-side electrode 10 of the element body 2 are respectively disposed. The auxiliary N-side electrode layer 15 and the auxiliary P-side electrode layer 14 of the submount member 11 are soldered. This soldering operation is performed by appropriately melting and solidifying these auxiliary electrode layers 15 and 14 since both auxiliary electrode layers 15 and 14 of the submount member 11 also serve as solder metal.
[0029]
As a result, as shown in FIG. 5, light is emitted from the back surface 3 a of the sapphire substrate 3 of the element body 2 as indicated by an arrow. In addition, the two P-side electrodes 10 of the element body are electrically connected to the silicon substrate 12 of the submount member 11, while the N-side electrode 9 of the element body 2 is insulated from the silicon substrate 12. In addition, the height dimension of the lamination | stacking part 7 of the element main body 2 shown in FIG. 1 is long compared with the height dimension of the lamination | stacking part 7 shown in FIG. 5 for convenience of explanation.
[0030]
In order to mount the semiconductor light emitting device 1 obtained as described above on the lead frame 17, the submount member 11 is formed on the upper surface of the P-side terminal portion 16a of the lead frame 16, as shown in FIG. Bonding is performed so that the lower surface of the submount member 11 is in a conductive state, and wire bonding 17 is applied between the band-shaped auxiliary N-side electrode layer 15 a of the submount member 11 and the N-side terminal portion 16 b of the lead frame 16.
[0031]
As a result, the P-side electrode 10 of the element body 2 is brought into conduction with the P-side terminal portion 16 a of the lead frame 16 through the conductive silicon substrate 12, and the N-side electrode 9 of the element body 2 is passed through the wire 17. The N-side terminal portion 16b of the lead frame 16 is brought into conduction. Thereafter, an LED lamp for blue light emission is obtained by resin sealing the outer peripheral portion of the semiconductor light emitting element 1.
[0032]
By adopting such a configuration, a region other than the formation position of the N-side electrode 9 on the back surface 3a of the transparent sapphire substrate 3 of the element body 2 becomes a light emitting region, and about 75% of the total area of the back surface 3a is a light emitting region. Used. Therefore, the light emission inhibition by the electrodes is drastically reduced as in the prior art, and a light emitting device having a sufficient light emission amount and high brightness can be obtained.
[0033]
In addition, the light emitted downward from the light emitting layer 5 of the element body 2 is reflected by the opaque submount member 11 (auxiliary electrode layers 14 and 15), and then is emitted from the back surface 3a of the sapphire substrate 3. Therefore, there is an advantage that the light use efficiency is improved.
[0034]
Furthermore, the use of the submount member 11 eliminates the need for wire bonding to the P-side electrode 10 and simplifies the wiring work and facilitates production.
[0035]
Next, a second embodiment of the semiconductor light emitting device 1 according to the present invention will be described with reference to FIGS. In the following description of the second embodiment, the same constituent elements as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.
[0036]
The semiconductor light emitting device 1 according to the second embodiment is different from the first embodiment described above in that, as shown in FIGS. 6 and 7, the entire surface of the device body 2 is made of SiO ₂ or Si ₃ by using the CVD method. The insulating layer 18 is covered with an insulating layer 18 made of N ₄ or the like, and through holes 19 and 20 are formed in the insulating layer 18 so as to communicate with the N-side electrode 9 and the P-side electrode 10, respectively. The metal layers 21 and 22 made of an alloy with Sn or an indium alloy are formed independently of each other. In this case, since the metal layers 21 and 22 are embedded in the through holes 19 and 20, the one metal layer 21 is brought into conduction with the N-side electrode 9, and the other The metal layer 22 is brought into conduction with the P-side electrode 10.
[0037]
The submount member 11 is configured such that the auxiliary N-side electrode layer 15 and the auxiliary P-side electrode layer 14 are formed corresponding to the shape and arrangement state of the metal layers 21 and 22 shown in FIG. The other parts, for example, the auxiliary N-side electrode layer 15 is formed through an insulating film 13 such as SiO ₂ are the same as those in the first embodiment.
[0038]
The element body 2 and the submount member 11 are bonded to each other with the metal layers 21 and 22 and the auxiliary electrode layers 15 and 14 as shown in FIG. By being integrated, the semiconductor light emitting element 1 is obtained. Even in the illustrated configuration, the P-side electrode 10 of the element body 2 is brought into conduction with the P-side terminal portion 16a of the lead frame 16 through the conductive silicon substrate 12, and the N-side electrode of the element body 2 is also provided. 9 is brought into conduction with the N-side terminal portion 16 b of the lead frame 16 through the wire 17.
[0039]
In this case, since the alignment between the metal layers 21 and 22 and the auxiliary electrode layers 15 and 14 can be easily performed, the joining work (soldering work) of these two layers, and the element main body 2 as well. The joining work with the submount member 11 can be performed very simply.
[0040]
Needless to say, the second embodiment can secure a sufficient amount of light emission as in the first embodiment.
[Brief description of the drawings]
FIG. 1 is a schematic longitudinal sectional front view showing an element body which is a component of a semiconductor light emitting element according to a first embodiment of the present invention.
FIG. 2 is a schematic plan view of an element body according to the first embodiment.
FIG. 3 is a schematic longitudinal front view of a submount member which is a component of the semiconductor light emitting device according to the first embodiment.
FIG. 4 is a schematic plan view of a submount member according to the first embodiment.
FIG. 5 is a schematic longitudinal sectional side view showing the overall configuration of the semiconductor light emitting device according to the first embodiment and its mounting state on a mounted member.
FIG. 6 is a schematic longitudinal sectional front view showing an element body which is a constituent element of a semiconductor light emitting element according to a second embodiment of the present invention.
FIG. 7 is a schematic plan view of an element body according to the second embodiment.
FIG. 8 is a schematic longitudinal sectional side view showing the overall configuration of the semiconductor light emitting device according to the second embodiment and its mounting state on a mounted member.
FIG. 9 is a schematic longitudinal sectional side view showing an overall configuration of a conventional semiconductor light emitting element and its attached state to a mounted member.
FIG. 10 is a schematic plan view of a conventional semiconductor light emitting device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Semiconductor light-emitting device 2 Element body 3 Transparent insulating substrate (sapphire substrate)
4 N-type semiconductor layer 5 Light emitting layer 6 P-type semiconductor layer 9 N-side electrode 10 P-side electrode 11 Submount member 12 Conductive substrate (silicon substrate)
14 Auxiliary P-side electrode layer 15 Auxiliary N-side electrode layer

Claims (2)

An N-type semiconductor layer, a light emitting layer, and a P-type semiconductor layer are formed on the surface of the transparent sapphire substrate, and a P-side electrode is formed on the surface of the P-type semiconductor layer. An element body formed by forming an N-side electrode on
An auxiliary N-side electrode layer formed so as to be insulative with the surface of the conductive substrate and facing the N-side electrode, and directly and so as to be conductive with respect to the surface of the conductive substrate. A submount member formed in a plane and having an auxiliary P-side electrode layer facing the P-side electrode,
Both the submount member and the element body are disposed so that the surface sides thereof face each other, and between the auxiliary N-side electrode layer and the N-side electrode, and between the auxiliary P-side electrode layer and the P The auxiliary P-side electrode layer reflects the light emitted from the light-emitting layer of the element body by integrating the submount member and the element body so that each side electrode is in a conductive state. A semiconductor light emitting device characterized in that it functions as a reflecting surface and emits light from the back side of the transparent sapphire substrate. A method of manufacturing a semiconductor light emitting device according to claim 1,
After the element body and the submount member are separately manufactured, the auxiliary N-side electrode layer and the N-side are formed in a state where the surface side of the element body and the surface side of the submount member are opposed to each other. A method of manufacturing a semiconductor light emitting device, wherein the electrode and the auxiliary P-side electrode layer and the P-side electrode are directly bonded to each other.

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