JP2010141115A - Method of manufacturing nitride semiconductor light emitting element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a nitride semiconductor light emitting element for suppressing deterioration of luminous efficiency. <P>SOLUTION: This method of manufacturing the nitride semiconductor light emitting element includes a process to form a ridge part 22 extending in the Y direction, and a process to form groove parts 33a and 33b extending in the Y direction so as to hold a region corresponding to the ridge part 22 between them in the X direction perpendicular to the Y direction. The process to form the groove parts 33a and 33b includes a process to form the groove part 33a in a region apart from the region corresponding to the ridge part 22 by a prescribed distance, and to form the groove part 33b in a region apart from a region corresponding to the ridge part 22 by a distance smaller than the prescribed distance, the groove part 33a is formed by scribing treatment by laser light, and the groove part 33b is formed by mechanical scribing treatment. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a nitride semiconductor light emitting device.

  Conventionally, a nitride semiconductor laser element including at least a semiconductor element layer having an elongated ridge portion extending in a predetermined direction is known as a nitride semiconductor light emitting element (see, for example, Patent Document 1). Hereinafter, an example of a conventional nitride semiconductor laser device will be briefly described.

  In a conventional nitride semiconductor laser element, a semiconductor element layer having an elongated ridge extending in the first direction is formed on a semiconductor substrate. The semiconductor element layer on the semiconductor substrate has a structure in which an n-side semiconductor layer, an active layer, and a p-side semiconductor layer are stacked in this order from the semiconductor substrate side. And the elongate convex part extended in a 1st direction is provided in the p side semiconductor layer, and the ridge part is comprised by the convex part. A p-side electrode is formed on the p-side semiconductor layer, and an n-side electrode is formed on the back surface of the semiconductor substrate.

  The conventional nitride semiconductor laser element described above is manufactured through the following process, for example.

  That is, first, an n-side semiconductor layer, an active layer, and a p-side semiconductor layer are epitaxially grown in this order on a wafer (semiconductor substrate) using a metal organic chemical vapor deposition (MOCVD) method or the like. Then, a predetermined portion of the p-side semiconductor layer is removed by etching using a photolithography technique and an etching technique. Thereby, stripe-shaped convex portions (portions that become ridge portions) extending in the first direction are formed in the p-side semiconductor layer. Further, a p-side electrode is formed on the p-side semiconductor layer and an n-side electrode is formed on the back surface of the semiconductor substrate by using a vacuum deposition method or the like. In this way, a structure is obtained in which element portions (portions that become nitride semiconductor laser elements) are arranged in a matrix.

Next, the structure in which the element portions are arranged in a matrix is cleaved along a second direction orthogonal to the direction in which the ridge portion extends. That is, the structure in which the element portions are arranged in a matrix is divided into bars, and a structure in which the element portions are arranged in a line in the second direction is formed. Thereafter, by irradiating the bar-shaped structure with laser light, a groove for separating the bar-shaped structure for each element portion is formed to extend in the first direction. Then, the bar-shaped structure is divided for each element portion along the groove for element separation.
JP 2006-229171 A

  Conventionally, in the configuration described above, the formation position of the ridge portion is shifted from the center of the element in the second direction (a direction orthogonal to the direction in which the ridge portion extends), that is, the ridge portion is on one end side of the element. Some have been sent. However, if such a nitride semiconductor laser device is to be manufactured by a conventional method, the region corresponding to the ridge portion is formed in the region corresponding to the ridge portion when the device isolation groove is formed on the side where the ridge portion is approached. It will be heated and deteriorated. As a result, there arises a problem that the luminous efficiency is lowered.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method for manufacturing a nitride semiconductor light-emitting element capable of suppressing a decrease in light emission efficiency. is there.

  In order to achieve the above object, a method of manufacturing a nitride semiconductor light emitting device according to one aspect of the present invention includes a step of forming a semiconductor device layer having a ridge portion extending in a first direction on a substrate, and the semiconductor device Forming a first electrode on the layer and forming a second electrode on the back surface of the substrate opposite to the surface on which the semiconductor element layer is formed; and a ridge portion in a second direction orthogonal to the first direction Forming a first groove portion and a second groove portion for element isolation extending in the first direction so as to sandwich a region corresponding to, and a step of dividing the element along the first groove portion and the second groove portion. Yes. In the step of forming the first groove portion and the second groove portion, the first groove portion is formed in a region separated from the region corresponding to the ridge portion by a predetermined distance, and is smaller than the predetermined distance from the region corresponding to the ridge portion. Including a step of forming the second groove portion in a region separated from the distance, the first groove portion is formed by a scribing process using a laser beam, and the second groove portion is formed by a mechanical scribing process.

  In the method of manufacturing a nitride semiconductor light emitting device according to this one aspect, as described above, the second groove portion for element isolation (the groove portion having a smaller distance from the region corresponding to the ridge portion) is mechanically scribed. By forming, even if the formation position of the second groove portion is close to the region corresponding to the ridge portion, the region corresponding to the ridge portion can be prevented from being heated when the second groove portion is formed. As a result, since deterioration due to heat in the region corresponding to the ridge portion is reduced, it is possible to suppress a decrease in light emission efficiency. In addition, by forming the first groove portion for element isolation (the groove portion with the larger distance from the region corresponding to the ridge portion) by a scribing process using laser light, the scribing process using laser light requires a wear member such as a blade. Therefore, the manufacturing cost can be reduced. Even if the first groove portion is formed by the scribing process using the laser beam, the formation position of the first groove portion is large from the region corresponding to the ridge portion, so that heat that causes deterioration during the formation of the first groove portion is obtained. Can be prevented from being applied to the region corresponding to the ridge portion. That is, there is no inconvenience that the luminous efficiency is greatly reduced by forming the first groove portion by the scribing process using the laser beam.

  In the method for manufacturing a nitride semiconductor light emitting device according to the aforementioned aspect, the first groove portion and the second groove portion are preferably formed from the second electrode side. In this case, it is difficult to apply heat to the region corresponding to the ridge portion of the second electrode, and it is possible to suppress an increase in resistance. Thereby, the fall of luminous efficiency is suppressed. Moreover, since the formation position of the 1st groove part and the 2nd groove part can be kept away from a ridge part, it can suppress that a ridge part is damaged. For this reason, the fall of luminous efficiency can be suppressed more.

  In the method for manufacturing a nitride semiconductor light emitting device according to the aforementioned aspect, it is preferable to concentrate defects in the formation region of the first groove. In this way, the defect concentration region is moved away from the ridge portion, and the occurrence of defects in the ridge portion can be suppressed. Thereby, the further suppression of the fall of luminous efficiency can be aimed at.

  As described above, according to the present invention, it is possible to easily obtain a method for manufacturing a nitride semiconductor light emitting device capable of suppressing a decrease in light emission efficiency.

  FIG. 1 is a cross-sectional view of a nitride semiconductor light emitting device manufactured using a method for manufacturing a nitride semiconductor light emitting device according to an embodiment of the present invention, and FIG. 2 is a nitride semiconductor light emitting device shown in FIG. It is an expanded sectional view of an active layer. Hereinafter, a configuration of a nitride semiconductor light emitting device manufactured using the method for manufacturing a nitride semiconductor light emitting device according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  The nitride semiconductor light emitting device manufactured using the method for manufacturing a nitride semiconductor light emitting device of this embodiment is a nitride semiconductor laser device 20, and is formed on an n-type GaN substrate 1 as shown in FIG. At least a semiconductor element layer 21 is provided. The n-type GaN substrate 1 is an example of the “substrate” in the present invention.

More specifically, a buffer layer 2 made of undoped Al _0.01 Ga _0.99 N is formed on the n-type GaN substrate 1 with a thickness of about 0.8 μm. An n-type cladding layer 3 made of n-type Al _0.07 Ga _0.93 N doped with Ge is formed on the buffer layer 2 with a thickness of about 1.8 μm.

An active layer 4 having a multiple quantum well (MQW) structure is formed on the n-type cladding layer 3. As shown in FIG. 2, the active layer 4 includes four barrier layers 4a made of undoped In _0.02 Ga _0.98 N and three well layers 4b made of undoped In _0.15 Ga _0.85 N. The barrier layer 4a and the well layer 4b have a thickness of about 20 nm and a thickness of about 3.5 nm, respectively, and are stacked alternately one by one. The active layer 4 may have a single quantum well (SQW) structure.

As shown in FIG. 1, a p-type cladding layer 5 made of p-type Al _0.07 Ga _0.93 N doped with Mg is formed on the active layer 4. The p-type cladding layer 5 is provided with a convex portion, and the thickness of the convex portion is about 0.45 μm, and the thickness of the flat portion other than the convex portion is about 0.05 μm. It has become. Further, a p-side contact layer 6 made of undoped In _0.07 Ga _0.93 N is formed on the convex portion of the p-type cladding layer 5 with a thickness of about 3 nm. A portion including the convex portion of the p-type cladding layer 5 and the p-side contact layer 6 functions as the ridge portion 22. The ridge portion 22 has an elongated shape extending in the resonator direction (perpendicular to the paper surface), and the width in the X direction (direction perpendicular to the direction in which the ridge portion 22 extends) is about 1.5 μm. It has become.

Although not shown, an n-side carrier block layer made of undoped Al _0.2 Ga _0.8 N is formed between the n-type cladding layer 3 and the active layer 4 with a thickness of about 20 nm. Between the mold clad layer 5, a p-side light guide layer and a p-side carrier block layer are formed in this order from the active layer 4 side. The p-side light guide layer is made of undoped In _0.01 Ga _0.99 N and has a thickness of about 0.1 μm. The p-side carrier block layer is made of undoped Al _0.2 Ga _0.8 N and has a thickness of about 20 nm.

  The semiconductor element layer 21 formed on the GaN substrate 1 includes the various nitride semiconductor layers (2 to 6) described above. The width in the X direction is about 200 μm.

  In the present embodiment, the defect concentration region 23 is provided on one end side (left side in FIG. 1) of the element, thereby reducing defects generated in other regions. The ridge portion 22 is moved away from the defect concentration region 23 by shifting the formation position of the ridge portion 22 to the other end side (right side in FIG. 1) opposite to the one end side of the element.

  On the ridge portion 22, a Pt layer having a thickness of about 1 nm and a Pd layer having a thickness of about 10 nm are sequentially formed. A stacked body including the Pt layer and the Pd layer is the p-side ohmic electrode 7. The p-side ohmic electrode 7 is an example of the “first electrode” in the present invention.

A current blocking layer 8 is formed on the flat portion of the p-type cladding layer 5, and the side surface of the ridge portion 22 is covered with the current blocking layer 8. The current blocking layer 8 is made of SiO ₂ and has a thickness of about 0.2 μm.

  A p-side pad electrode 9 connected to the p-side ohmic electrode 7 through the opening of the current blocking layer 8 is formed on the current blocking layer 8. The p-side pad electrode 9 is composed of a laminate including a Ti layer having a thickness of about 30 nm, a Pd layer having a thickness of about 150 nm, and an Au layer having a thickness of about 3 μm. The layers are stacked in the order of Pd layer and Au layer from the lower layer to the upper layer. The p-side pad electrode 9 is an example of the “first electrode” in the present invention.

  Further, an Al layer having a thickness of about 6 nm and a thickness of about 10 nm are sequentially formed from the n-type GaN substrate 1 side on the back surface of the n-type GaN substrate 1 opposite to the surface on which the semiconductor element layer 21 is formed. And a Au layer having a thickness of about 300 nm. A stacked body including the Al layer, the Pd layer, and the Au layer is an n-side electrode (n-side ohmic electrode and n-side pad electrode) 10. The n-side electrode 10 is an example of the “second electrode” in the present invention.

  In the nitride semiconductor light emitting device manufacturing method of the present embodiment, the nitride semiconductor laser device 20 having the above-described configuration can be manufactured.

  By the way, when the method for manufacturing a nitride semiconductor light emitting device of this embodiment is used, the n-type GaN substrate 1 has a depth halfway from the n-side electrode 10 on each of one end side and the other end side in the X direction of the device. Processing traces (cut portions) 20a and 20b that reach the depths remain. The processing mark 20a on the one end side is formed by performing a scribing process using a laser beam during the element isolation process, and the processing mark 20b on the other end side is subjected to a mechanical scribing process during the element isolation process. Is formed. The cut depth of the processing trace 20a on one end side (depth in the thickness direction of the n-type Ga substrate 1) is about 40 μm, and the cut depth of the processing trace 20b on the other end side is about 5 μm.

  3 to 11 are a cross-sectional view and a plan view for explaining a method for manufacturing a nitride semiconductor light emitting device according to an embodiment of the present invention. A method for manufacturing a nitride semiconductor light emitting device according to an embodiment of the present invention (a process for manufacturing a nitride semiconductor laser device) will be described below with reference to FIGS.

  In this embodiment, first, as shown in FIG. 3, various nitride semiconductor layers (2 to 6) are formed on an n-type GaN substrate (wafer) 1 by using a metal organic chemical vapor deposition (MOCVD) method. Epitaxially grow.

Specifically, an n-type GaN substrate 1 provided with a defect concentration region 23 is prepared and set in an MOCVD apparatus. Then, while maintaining the substrate temperature at about 1160 ° C., H ₂ gas as a carrier gas and NH ₃ gas, trimethyl gallium (TMGa) gas, and trimethyl aluminum (TMAl) gas as source gases are supplied, and about 1 Epitaxial growth is performed at a speed of 1 μm / h. Thereby, the buffer layer 2 (thickness: about 0.8 μm) made of undoped Al _0.01 Ga _0.99 N is formed on the n-type GaN substrate 1.

Thereafter, a monogermane (GeH ₄ ) gas containing Ge as an n-type dopant is newly added as a source gas, and epitaxial growth is performed at a rate of about 1.1 μm / h, whereby Ge is formed on the buffer layer 2. An n-type cladding layer 3 (thickness: about 1.8 μm) made of doped n-type Al _0.07 Ga _0.93 N is formed. Then, by stopping the supply of GeH ₄ gas and performing epitaxial growth at a rate of about 1 μm / h, an n-side carrier block layer (thickness: about 20 nm) made of undoped Al _0.2 Ga _0.8 N is formed on the n-type cladding layer 3. Form. For simplification of the drawing, the n-side carrier block layer is not shown.

Next, the substrate temperature is lowered from about 1160 ° C. to about 850 ° C. Then, by supplying N ₂ gas as a carrier gas and NH ₃ gas, triethyl gallium (TEGa) gas and trimethyl indium (TMIn) gas as source gases, an n-side carrier block layer (not shown) is provided. _{Furthermore, the} four barrier layers 4a (see FIG. 2) made of undoped In _0.02 Ga _0.98 N and the three well layers 4b (see FIG. 2) made of undoped In _0.15 Ga _0.85 N have a speed of about 0.25 μm / h. Are alternately epitaxially grown one by one. As a result, the active layer 4 having the MQW structure including the four barrier layers 4a (thickness: about 20 nm) and the three well layers 4b (thickness: about 3.5 nm) is formed.

Subsequently, a p-side light guide layer (thickness: about 0.1 μm) made of undoped In _0.01 Ga _0.99 N is formed on the active layer 4 by performing epitaxial growth under the same conditions. Thereafter, the raw material gas is changed to NH ₃ gas, TMGa gas, and TMAl gas, and epitaxial growth is performed at a rate of about 1.2 μm / h, whereby the p-side light guide layer is made of undoped Al _0.2 Ga _0.8 N. A p-side carrier block layer (thickness: about 20 nm) is formed. For simplification of the drawing, the p-side light guide layer and the p-side carrier block layer are not shown.

Next, the substrate temperature is increased from about 850 ° C. to about 1160 ° C. Then, a cyclopentadienylmagnesium (Mg (C ₅ H ₅ ) ₂ ) gas containing Mg as a p-type dopant is newly added as a source gas, and epitaxial growth is performed at a rate of about 1.1 μm / h, A p-type cladding layer 5 (thickness: about 0.45 μm) made of p-type Al _0.07 Ga _0.93 N doped with Mg is formed on a p-side carrier block layer (not shown). Further, the substrate temperature is lowered from about 1160 ° C. to about 850 ° C., the supply of Mg (C ₅ H ₅ ) ₂ gas is stopped, and epitaxial growth is performed at a rate of about 0.25 μm / h, whereby the p-type cladding layer 5 A p-side contact layer 6 (thickness: about 3 nm) made of undoped In _0.07 Ga _0.93 N is formed thereon.

  As described above, the semiconductor element layer 21 composed of various nitride semiconductor layers (2 to 6) is formed on the n-type GaN substrate 1. Note that defects of the n-type GaN substrate 1 propagate to the semiconductor element layer 21. That is, the defect concentration region 23 is also provided in the semiconductor element layer 21.

Next, as shown in FIG. 4, after forming an etching mask (SiO ₂ film) 30 in a region corresponding to the ridge portion 22 on the p-side contact layer 6, a reactive ion etching method using Cl ₂ gas is used. Then, etching is removed from the upper surface of the p-side contact layer 6 to a depth in the middle of the p-type cladding layer 5 (a depth of about 0.4 μm from the upper surface of the p-type cladding layer 5). Subsequently, the etching mask 30 is removed. As a result, as shown in FIG. 5, the semiconductor element layer 21 has a striped ridge portion extending in the Y direction (first direction) (a portion including the convex portion of the p-type cladding layer 5 and the p-side contact layer 6). 22 is formed. When the ridge portion 22 is formed in the semiconductor element layer 21, the ridge portion 22 is moved away from the defect concentration region 23. For this reason, a part with a large space | interval of the adjacent ridge part 22 and a small part will be mixed.

Thereafter, as shown in FIG. 6, a SiO ₂ film having a thickness of about 0.2 μm is formed on the entire surface by plasma CVD, and then the region corresponding to the ridge portion 22 of the SiO ₂ film is removed. As a result, a current blocking layer (SiO ₂ film having a thickness of about 0.2 μm) 8 having an opening in a region corresponding to the ridge portion 22 and covering the side surface of the ridge portion 22 is flattened on the p-type cladding layer 5. Form on the part.

  Then, a Pt layer having a thickness of about 1 nm and a Pd layer having a thickness of about 10 nm are stacked in this order on the ridge portion 22 using an electron beam evaporation method. Thereby, the p-side ohmic electrode 7 which consists of a laminated body containing a Pt layer and a Pd layer is formed. Subsequently, a Ti layer having a thickness of about 30 nm, a Pd layer having a thickness of about 150 nm, and an Au layer having a thickness of about 3 μm are formed in this order on the current blocking layer 8 by using an electron beam evaporation method. Laminate with. Thereby, the p-side pad electrode 9 made of a laminate including the Ti layer, the Pd layer, and the Au layer is formed. When the p-side pad electrode 9 is formed, the p-side pad electrode 9 is connected to the p-side ohmic electrode 7 through the opening of the current blocking layer 8.

  Further, after polishing the n-type GaN substrate 1 from the back surface side to a predetermined thickness, an Al layer having a thickness of about 6 nm is formed on the back surface of the n-type GaN substrate 1 using an electron beam evaporation method, A Pd layer having a thickness of 10 nm and an Au layer having a thickness of about 300 nm are formed in this order. In this way, as shown in FIGS. 7 and 8, the n-side electrode 10 made of a laminate including the Al layer, the Pd layer, and the Au layer is formed, and the element portion (the portion that becomes the nitride semiconductor laser element 20) ) Is obtained in a matrix.

  Next, a groove (not shown) for cleaving the structure 31 is formed so as to extend in the X direction, and the structure 31 is cleaved along the cleavage groove. In this way, as shown in FIG. 9, a bar-shaped structure 32 in which the element portions are arranged in a line in the X direction is obtained. The cleavage surface 32a of the structure 32 is a resonator surface. Thereafter, although not shown, an end face coating film is formed on the cleavage surface 32 a of the structure 32.

  After obtaining the bar-shaped structure 32, as shown in FIGS. 10 and 11, a groove 33 for separating the structure 32 for each element part is formed so as to extend in the Y direction (first direction). . When forming the element isolation trench 33, the back surface side (n side) of the structure 32 is formed so as to be cut through the n side electrode 10 until reaching the middle depth of the n-type GaN substrate 1. A scribing process is performed from the electrode 10 side. Further, one cut is made near the center between regions corresponding to the ridge portions 22 adjacent to each other in the X direction (second direction). As a result, in the X direction (second direction), the groove portion 33 for element isolation sandwiches the region corresponding to the ridge portion 22 and is located in a region where the distance from the region corresponding to the ridge portion 22 is large. A (first groove portion) 33a and a groove portion (second groove portion) 33b located in a region having a small distance from the region corresponding to the ridge portion 22 are provided. The formation region of the one groove portion 33a is a region that is separated from the region corresponding to the ridge portion 22 by a distance of about 125 μm, and where defects are concentrated. In addition, the formation region of the other groove portion 33b is a region that is separated from the region corresponding to the ridge portion 22 by a distance of about 75 μm and has few defects.

  Here, in the present embodiment, when forming the element isolation trench 33 (grooves 33a and 33b), a scribing process using a laser beam and a mechanical scribing process are used in combination. Specifically, one groove 33a is formed by a scribing process using a laser beam, and the other groove 33b is formed by a mechanical scribing process (for example, a scribing process using a diamond cutter). In this case, the groove depths of the one groove 33a obtained by the scribing process using the laser beam and the other groove 33b obtained by the mechanical scribing process are different from each other. That is, the cut depth of one groove 33a obtained by the scribing process using laser light is about 40 μm, and the cut depth of the other groove 33b obtained by the mechanical scribing process is about 5 μm.

  In FIG. 10, one groove portion 33 a obtained by the scribing process with the laser beam is illustrated so as not to reach the cleavage surface 32 a of the structure 32, but the one groove portion 33 a is the cleavage surface 32 a of the structure body 32. You may reach up to. However, debris (n-type GaN substrate 1 and n side) generated by irradiating the laser beam if one groove 33a obtained by the scribing process using the laser beam does not reach the cleavage surface 32a of the structure 32. Adhesion of the constituent material of the electrode 10 in the form of powder by evaporation to the resonator surface is suppressed, and a decrease in emission intensity can be suppressed. Further, in FIG. 10, the other groove 33 b obtained by the mechanical scribing process is illustrated as reaching the cleavage surface 32 a of the structure 32, but the other groove 33 b is the cleavage surface of the structure 32. It does not have to reach 32a.

  Finally, the structure 32 is divided along the element isolation groove 33 so that the structure 33 is separated for each element part. In this way, the nitride semiconductor laser device 20 shown in FIG. 1 is manufactured.

  In the present embodiment, as described above, the groove 33b for element isolation having a smaller distance from the region corresponding to the ridge 22 is formed by a mechanical scribing process, whereby the formation position of the groove 33b is changed to the ridge. Even if it is close to the region corresponding to 22, it is possible to suppress the region corresponding to the ridge portion 22 from being heated when the groove 33 b is formed, and the deterioration of the region corresponding to the ridge portion 22 due to heat is reduced. . Specifically, it is difficult to apply heat to the region corresponding to the ridge portion 22 of the n-side electrode 10 and it is possible to suppress the resistance from increasing. As a result, it is possible to suppress a decrease in luminous efficiency. In addition, since the element isolation groove 33a having a larger distance from the region corresponding to the ridge portion 22 is formed by a scribing process using a laser beam, the laser beam scribing process does not require a wear member such as a blade. The manufacturing cost can be reduced. Even if the groove 33a is formed by a scribing process using a laser beam, the formation position of the groove 33a is large from the region corresponding to the ridge 22, so that heat that causes deterioration during formation of the groove 33a is generated. It is possible to suppress the addition to the region corresponding to the ridge portion 22. That is, there is no inconvenience that the luminous efficiency is greatly reduced by forming the groove 33a by a scribing process using a laser beam.

  In the present embodiment, as described above, by forming the groove portions 33a and 33b for element isolation from the n-side electrode 10 side, the formation positions of the groove portions 33a and 33b can be moved away from the ridge portion 22. Damage to the ridge portion 22 can be suppressed. Thereby, the fall of luminous efficiency can be suppressed more.

  Further, in the present embodiment, as described above, the defect concentration region 23 is moved away from the ridge portion 22 by concentrating defects in the formation region of the element isolation groove portion 33a, and the ridge portion 22 has a defect. Can be suppressed. Thereby, the further suppression of the fall of luminous efficiency can be aimed at.

  Next, the results of experiments conducted to confirm the above effects will be described.

  In this confirmation experiment, a nitride semiconductor laser device was first manufactured using the manufacturing method of the present embodiment, and the threshold current, operating current, operating voltage, and light emission efficiency were examined. Thereafter, the threshold current, the operating current, the operating voltage in a state where the laser scriber has scratched a region close to the region corresponding to the ridge portion of the nitride semiconductor laser element (a region separated by 40 μm from the ridge portion). And the luminous efficiency was investigated. As a result, if a laser scriber is used to scratch a region close to the region corresponding to the ridge portion of the nitride semiconductor laser device, the threshold current, operating current, and operation are compared to the nitride semiconductor laser device before the scratch is made. It has been found that the voltage and the luminous efficiency are degraded. Specifically, the threshold current deteriorated by 1.7%, the operating current deteriorated by 1.1%, and the operating voltage deteriorated by 1.2%. In addition, the luminous efficiency deteriorated by 0.5%.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

1 is a cross-sectional view of a nitride semiconductor light emitting device manufactured using a method for manufacturing a nitride semiconductor light emitting device according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of an active layer of the nitride semiconductor light emitting device shown in FIG. It is sectional drawing for demonstrating the manufacturing method of the nitride semiconductor light-emitting device by one Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the nitride semiconductor light-emitting device by one Embodiment of this invention. It is a top view for demonstrating the manufacturing method of the nitride semiconductor light-emitting device by one Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the nitride semiconductor light-emitting device by one Embodiment of this invention. It is a top view for demonstrating the manufacturing method of the nitride semiconductor light-emitting device by one Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the nitride semiconductor light-emitting device by one Embodiment of this invention. It is a top view for demonstrating the manufacturing method of the nitride semiconductor light-emitting device by one Embodiment of this invention. It is a top view for demonstrating the manufacturing method of the nitride semiconductor light-emitting device by one Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the nitride semiconductor light-emitting device by one Embodiment of this invention.

Explanation of symbols

1 n-type GaN substrate (substrate)
7 p-side ohmic electrode (first electrode)
9 p-side pad electrode (first electrode)
10 n-side electrode (second electrode)
21 Semiconductor element layer 22 Ridge portion 23 Defect concentration region 33 Groove portion 33a Groove portion (first groove portion)
33b Groove (second groove)

Claims (3)

Forming a semiconductor element layer having a ridge portion extending in the first direction on the substrate;
Forming a first electrode on the semiconductor element layer and forming a second electrode on the back surface of the substrate opposite to the surface on which the semiconductor element layer is formed;
Forming element isolation first and second groove portions extending in the first direction so as to sandwich a region corresponding to the ridge portion in a second direction orthogonal to the first direction;
Dividing the element along the first groove and the second groove,
In the step of forming the first groove portion and the second groove portion, the first groove portion is formed at a predetermined distance from a region corresponding to the ridge portion, and the predetermined groove is formed from the region corresponding to the ridge portion. Forming the second groove portion in a region separated by a distance smaller than the distance,
The method of manufacturing a nitride semiconductor light emitting device, wherein the formation of the first groove is performed by a scribing process using a laser beam, and the formation of the second groove is performed by a mechanical scribing process.   The method for manufacturing a nitride semiconductor light emitting element according to claim 1, wherein the first groove portion and the second groove portion are formed from the second electrode side.   3. The method for manufacturing a nitride semiconductor light emitting element according to claim 1, wherein defects are concentrated in a formation region of the first groove portion.

Images