JP2005203737A - Method of manufacturing semiconductor light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor light-emitting device whereby light can be efficiently captured from the semiconductor light-emitting device and a damage on the semiconductor light-emitting device can be prevented during manufacturing. <P>SOLUTION: The method of manufacturing the semiconductor light-emitting device includes (1) a step of stacking a layer containing polycarbodiimide on a light-capturing surface of the semiconductor light-emitting device, and (2) a step of forming asperities on the layer containing polycarbodiimide. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

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

  In order to increase the light extraction efficiency of the semiconductor light emitting device, it has been reported that a concavo-convex structure is formed on the light extraction surface of the semiconductor light emitting device (see, for example, Patent Document 1).

  However, in order to process the concavo-convex shape on the semiconductor surface as described above, it is necessary to perform etching by a method of RIE (reactive ion etching) or ion milling, which requires labor and cost for the process.

Therefore, the light extraction efficiency is improved by forming an antireflection film by adding TiO ₂ to polyimide resin on the light extraction surface of the semiconductor light emitting device, and further forming irregularities on the film using a mold press. It is known to do (see, for example, Patent Document 2).
JP 2000-196152 A Japanese Patent Application No. 2003-174191

  However, since polyimide is used for the film, it is usually necessary to apply a pressure greater than 1 MPa to the semiconductor light emitting element at 300 ° C. or higher in order to form irregularities using a mold press on the film. is there. At such high temperature and pressure, the semiconductor light emitting device may be damaged.

  Accordingly, an object of the present invention is to provide a method for manufacturing a semiconductor light emitting device that has good light extraction efficiency from the semiconductor light emitting device and can prevent damage to the semiconductor light emitting device during manufacturing.

That is, the present invention
(A) (a) a step of laminating a layer containing polycarbodiimide on the light extraction surface side of the semiconductor light-emitting device, and (b) a method of manufacturing a semiconductor light-emitting device comprising the step of forming irregularities on the layer containing polycarbodiimide,
(B) The polycarbodiimide is represented by the general formula (1):

(Wherein R represents a diisocyanate residue, R ¹ represents a monoisocyanate residue, and n is an integer of 1 to 100)
(A) The manufacturing method of the semiconductor light-emitting device according to (A), and (C) the thickness of the polycarbodiimide layer before unevenness formation is 0.5 to 10 μm ( The present invention relates to a method for producing a semiconductor light emitting device according to A) or (B).

  ADVANTAGE OF THE INVENTION According to this invention, the damage of the semiconductor light-emitting device under manufacture can be prevented, and a semiconductor light-emitting device with high light extraction efficiency can be manufactured.

The method for producing a semiconductor light emitting device of the present invention includes:
(1) a step of laminating a layer containing polycarbodiimide (sometimes referred to as a polycarbodiimide layer in the present specification) on the light extraction surface side of the semiconductor light emitting device; and
(2) including a step of forming irregularities in the layer containing the polycarbodiimide.

  An example of a semiconductor light emitting device manufactured by the manufacturing method of the present invention is shown in FIG. The substrate 1 has a structure in which one or more semiconductor layers 2 are stacked on one side. On the semiconductor layer 2, an electrode 4 is formed, and a polycarbodiimide layer 3 processed into an uneven shape is laminated. Further, the polycarbodiimide layer 3 and a part of the semiconductor layer 2 are selectively removed by etching to form an electrode 5. Light emission from the semiconductor light emitting element is observed from the surface opposite to the substrate 1, that is, the surface on which the semiconductor layer 2 and the polycarbodiimide layer 3 are stacked (in this specification, sometimes referred to as a light extraction surface). .

  By laminating a polycarbodiimide layer (refractive index = about 1.7 to 1.8) on the semiconductor layer, the semiconductor layer (refractive index = about 2.5 to 3.5) and the ambient atmosphere (for example, air ( Refractive index difference of about 1), epoxy resin (refractive index = about 1.54), etc. is relaxed. As a result, the critical angle between each layer widens, and light is extracted from the semiconductor light emitting device. By applying uneven processing to the polycarbodiimide layer, the surface uneven structure increases the amount of incident light within the critical angle between the two layers, so that the effect of improving the light extraction efficiency is exhibited. . Furthermore, the use of the polycarbodiimide layer can also prevent damage to the semiconductor light emitting device during manufacture.

  Examples of the substrate used in the present invention include a sapphire substrate, a silicon carbide substrate, a silicon substrate, and the like, and a sapphire substrate is preferable from the viewpoints of securing light transmittance and refractive index and supply stability to the market. The thickness of the substrate is preferably 50 to 500 μm, more preferably 50 to 80 μm.

  Examples of the semiconductor layer used in the present invention include semiconductor layers usually used in the field such as a GaN layer, a GaP layer, a GaS layer, and a GaAs layer, and are appropriately selected depending on the emission color. The semiconductor layer may be formed by a known method. For example, the entire semiconductor layer is formed on the substrate by the MOVCD method and includes all of the buffer layer, p layer, light emitting layer, n layer, and the like formed on the substrate. The thickness of is preferably 1 to 5 μm.

  Examples of the material for the electrode used in the present invention include gold, silver, nickel, chromium, copper, and the like. Gold is preferable from the viewpoint of securing the bondability and surface stability in the post-mounting process.

  The electrode may be formed on the semiconductor layer before the formation of the polycarbodiimide layer by a known method such as vapor deposition, or may be formed on the semiconductor layer after the formation of the polycarbodiimide layer. In the former case, a polycarbodiimide layer is laminated on the electrode. After forming the polycarbodiimide layer, a resist mask is formed on the polycarbodiimide layer, and the polycarbodiimide layer on the electrode is removed by RIE or the like. Then, the electrode may be exposed. In the latter case, a resist mask is formed on the polycarbodiimide layer, the polycarbodiimide layer in the electrode forming portion is removed by RIE, and then an electrode is formed in the electrode forming portion by vapor deposition or the like.

  Examples of the polycarbodiimide used in the present invention include various polycarbodiimides. From the viewpoint of obtaining a high refractive index, the formula (1):

(Wherein R represents a diisocyanate residue, R ¹ represents a monoisocyanate residue, and n is an integer of 1 to 100)
The polycarbodiimide represented by these is preferable.

  In the present invention, the polycarbodiimide represented by the formula (1) is obtained by subjecting one or more diisocyanates to a condensation reaction and end-capping with monoisocyanate.

In the formula (1), R represents a diisocyanate residue used as a raw material, and R ¹ represents a monoisocyanate residue similarly used as a raw material. Moreover, n is an integer of 1-100.

  The diisocyanate and monoisocyanate as raw materials may be either aromatic or aliphatic, and aromatic or aliphatic can be used alone or in combination. In the present invention, aromatic ones are preferably used from the viewpoint of increasing the refractive index of polycarbodiimide. That is, it is preferable that at least one of diisocyanate and monoisocyanate includes an aromatic one or an aromatic one, or both are aromatic. Among them, it is more preferable that the diisocyanate is aliphatic and aromatic, and the monoisocyanate is more aromatic, and it is particularly preferable that both the diisocyanate and the monoisocyanate are aromatic. preferable.

  Examples of the diisocyanate used in the present invention include hexamethylene diisocyanate, dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, Isophorone diisocyanate, cyclohexyl diisocyanate, lysine diisocyanate, methylcyclohexane-2,4′-diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyl ether diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate Naphthalene diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, 3, '-Dimethoxy-4,4'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate, 2,2-bis [4- (4-isocyanatophenoxy) phenyl ] Hexafluoropropane, 2,2-bis [4- (4-isocyanatophenoxy) phenyl] propane and the like.

  Among them, at least one selected from the group consisting of tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate and naphthalene diisocyanate, hexamethylene diisocyanate and dodecamethylene diisocyanate is preferably used from the point of obtaining a high refractive index, and naphthalene diisocyanate. Are more preferably used.

  These diisocyanates can be used alone or in admixture of two or more, but from the viewpoint of heat resistance, it is preferable to use a mixture of two or three.

  As the diisocyanate as the raw material, those containing 10 mol% or more (upper limit of 100 mol%) of aromatic diisocyanate in the total diisocyanate used are suitable. As the diisocyanate, it is desirable to use the preferred ones.

  Examples of the monoisocyanate used in the present invention include cyclohexyl isocyanate, phenyl isocyanate, p-nitrophenyl isocyanate, p- and m-tolyl isocyanate, p-formylphenyl isocyanate, p-isopropylphenyl isocyanate, 1-naphthyl isocyanate and the like. Is mentioned.

  As the monoisocyanate, aromatic monoisocyanate is preferably used, and 1-naphthyl isocyanate is more preferably used from the viewpoint that reaction between monoisocyanates does not occur and end-capping of polycarbodiimide proceeds efficiently. Is done.

  These monoisocyanates can be used alone or in admixture of two or more.

  The monoisocyanate used for end-capping is preferably used in the range of 1 to 10 moles with respect to 100 moles of the diisocyanate component used from the viewpoint of storage stability.

  The polycarbodiimide used in the present invention is produced by subjecting diisocyanate as a raw material to carbodiimidization by a condensation reaction in a predetermined solvent in the presence of a carbodiimidization catalyst and end-capping with monoisocyanate.

  The reaction temperature for the condensation reaction of diisocyanate is usually 0 to 150 ° C., preferably 10 to 120 ° C.

  When aliphatic diisocyanate and aromatic diisocyanate are used in combination with the raw material diisocyanate, it is preferably reacted at a low temperature. As reaction temperature, 0-50 degreeC is preferable and 10-40 degreeC is more preferable. A reaction temperature within such a range is preferable because the condensation reaction between the aliphatic diisocyanate and the aromatic diisocyanate proceeds sufficiently.

  When it is desired to further react the aromatic diisocyanate present in excess in the reaction solution with respect to the polycarbodiimide composed of aliphatic diisocyanate and aromatic diisocyanate, the reaction temperature is preferably 40 to 150 ° C., 50 to 120 ° C is more preferred. A reaction temperature within such a range is preferable because the reaction can be smoothly advanced using an arbitrary solvent.

  The diisocyanate concentration in the reaction solution is preferably 5 to 80% by weight. A diisocyanate concentration within this range is preferable because carbodiimidization proceeds sufficiently and the reaction can be easily controlled.

  End-capping with monoisocyanate can be carried out by adding monoisocyanate to the reaction solution throughout the initial, intermediate, final or general stages of carbodiimidization of diisocyanate. The monoisocyanate is preferably an aromatic monoisocyanate.

  Any known phosphorus-based catalyst is preferably used as the carbodiimidization catalyst. For example, 1-phenyl-2-phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, 3-methyl-1-phenyl-2-phospholene- Examples include 2-oxides or phospholene oxides such as 3-phospholene isomers thereof.

  As the solvent (organic solvent) used for the production of polycarbodiimide, known solvents are used. Specifically, halogenated hydrocarbons such as tetrachloroethylene, 1,2-dichloroethane, chloroform, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, cyclic ether solvents such as tetrahydrofuran and dioxane, toluene, xylene, and the like And aromatic hydrocarbon-based solvents. These solvents can be used alone or in admixture of two or more. These solvents are also used when dissolving the obtained polycarbodiimide.

The end point of the reaction is confirmed by observation of absorption (2140 cm ⁻¹ ) derived from a carbodiimide structure (N═C═N) by infrared spectroscopic analysis (IR measurement) and disappearance of absorption derived from isocyanate (2280 cm ⁻¹ ). be able to.

  After completion of the carbodiimidization reaction, polycarbodiimide is usually obtained as a solution, but further, a solution obtained in a poor solvent such as methanol, ethanol, isopropyl alcohol, hexane or the like is added, polycarbodiimide is precipitated as a precipitate, and unreacted The monomer or catalyst may be removed.

  In order to prepare a solution of polycarbodiimide recovered as a precipitate, the precipitate is washed by a predetermined operation, dried, and dissolved again in an organic solvent. By performing such an operation, the storage stability of the polycarbodiimide solution can be improved.

  Furthermore, when a by-product is contained in the polycarbodiimide solution, for example, by using an appropriate adsorbent, the by-product may be adsorbed and removed for purification. Examples of the adsorbent include alumina gel, silica gel, activated carbon, zeolite, activated magnesium oxide, activated bauxite, fruct earth, activated clay, and molecular sieve carbon. These adsorbents may be used alone or in combination of two or more. can do.

  From the above, the polycarbodiimide used in the present invention is obtained. From the viewpoint of increasing the light extraction efficiency, it is preferable that the main chain structure is composed of aromatic and aliphatic diisocyanates and the end capping is composed of aromatic monoisocyanates, and the main chain structure is composed of aromatic diisocyanates. More preferably, the end capping is made of aromatic monoisocyanate.

Specifically, the polycarbodiimide is preferably an aromatic diisocyanate residue in which 10 mol% or more (upper limit is 100 mol%) of the diisocyanate residue represented by R in the formula (1), What the monoisocyanate residue represented by R < ¹ > of Formula (1) is an aromatic monoisocyanate residue is preferable. The diisocyanate residue may be at least one selected from the group consisting of tolylene diisocyanate residue, 4,4′-diphenylmethane diisocyanate residue, naphthalene diisocyanate residue, hexamethylene diisocyanate residue and dodecamethylene diisocyanate residue. A naphthalene diisocyanate residue is more preferable, and the aromatic monoisocyanate residue is preferably a 1-naphthyl isocyanate residue.

  Further, for the purpose of increasing the refractive index, metal oxide fine particles such as titanium oxide and zirconium oxide may be added to the polycarbodiimide layer. The average particle diameter of the metal oxide fine particles is preferably 2 to 100 nm from the viewpoint of ensuring transparency. The content of the metal oxide fine particles in the polycarbodiimide layer is preferably 20 to 50% by volume, more preferably 22 to 30% by volume with respect to the solid content of the polycarbodiimide. Thus, the refractive index of a polycarbodiimide layer can be made into about 1.8-2.1 by adding metal oxide microparticles | fine-particles to a polycarbodiimide layer.

  The polycarbodiimide layer can be formed, for example, as follows. A solution obtained by dissolving the polycarbodiimide represented by the general formula (1) in a solvent such as cyclohexanone or toluene, and optionally adding and dispersing metal oxide fine particles, is a known method such as casting or spin coating. Is applied to the surface of the semiconductor layer and dried to form a polycarbodiimide layer. The application to the surface of the semiconductor layer may be performed before cutting into individual elements as described above, or may be performed after cutting.

  Drying of the polycarbodiimide solution applied to the surface of the semiconductor layer is preferably performed at a temperature and a time at which the solvent can be removed so that the polycarbodiimide is dried without allowing the curing reaction of the polycarbodiimide to proceed so much. The specific drying temperature is preferably 20 to 200 ° C, more preferably 50 to 150 ° C. The time is preferably 5 to 60 minutes, more preferably 10 to 20 minutes.

  The polycarbodiimide layer can be stacked on the semiconductor light-emitting element by directly forming on the surface of the semiconductor layer as described above. However, as described below, a polycarbodiimide sheet is prepared in advance, and the sheet is formed on the semiconductor layer. It can also be stacked on a semiconductor light emitting device by being arranged on the surface.

  The polycarbodiimide sheet can be formed, for example, as follows. A solution obtained by dissolving the polycarbodiimide represented by the general formula (1) in a solvent such as cyclohexanone or toluene, and optionally adding and dispersing metal oxide fine particles, is a known method such as casting or spin coating. For example, a polycarbodiimide sheet is formed by applying to the surface of a separator treated with silicone and drying. Next, the sheet is disposed on the semiconductor layer to form a polycarbodiimide layer. The separator may be removed before the polycarbodiimide sheet is stacked on the semiconductor light emitting element, or may be removed after being stacked on the semiconductor light emitting element.

  It is preferable to dry the polycarbodiimide sheet applied to the surface of the separator at a temperature and a time at which the solvent can be removed so that the polycarbodiimide sheet is dried without causing the curing reaction of the polycarbodiimide to proceed so much. The specific drying temperature is preferably 20 to 350 ° C, more preferably 50 to 200 ° C. The time is preferably 30 seconds to 3 minutes.

  The thickness of the polycarbodiimide layer obtained as described above is preferably 0.5 to 30 μm, and preferably 0.5 to 20 μm from the viewpoint of preventing the attenuation of light during light transmission and ensuring the processability of unevenness. More preferably, 0.5-10 micrometers is further more preferable, and 1-5 micrometers is still more preferable. The refractive index is preferably 1.7 or more, more preferably 1.85 or more, from the viewpoint of further increasing the light extraction efficiency. Furthermore, the elastic modulus at 150 ° C. is preferably 0.2 to 3 GPa and more preferably 0.2 to 1 GPa from the viewpoint of ensuring the processability of the unevenness.

  Formation of irregularities on the polycarbodiimide layer formed as described above can be performed, for example, by heating and pressurizing the surface of the polycarbodiimide layer using a mold having predetermined irregularities. In the present invention, as a mold, for example, a polyimide sheet or polycarbonate sheet processed with predetermined irregularities by laser processing can be used as a master, which is produced by electroforming a metal such as nickel. .

  The unevenness is formed by the mold, for example, by aligning the mold 6 as shown in FIG. 2 so that the polycarbodiimide layer can be formed in the unevenness, and further, as shown in FIG. By inserting a semiconductor light emitting element between the hot press plates 7 and performing heating and pressurization, irregularities can be formed in the polycarbodiimide layer laminated in the step (1).

  The heating and pressurizing conditions are preferably 70 to 200 ° C., more preferably 100 to 180 ° C., and preferably 0.1 to 10 MPa, more preferably 0.1 to 3 MPa. The conditions are preferably 5 seconds to 3 minutes, more preferably 10 seconds to 1 minute.

  The shape of the unevenness formed on the surface of the polycarbodiimide layer is not particularly limited as long as it is designed to improve the light extraction efficiency, but from the viewpoint of ensuring the processing accuracy of the mold for obtaining the uneven shape, hemispherical A conical shape or a pyramid shape is preferable. In order to optimize the light extraction efficiency, the distance (height) between the top and bottom of each irregularity is preferably 1 to 5 μm, the width of each convex part is preferably 1 to 5 μm, and the pitch of the top part is convex. The width of the part is preferably 1.0 to 2.0 times, more preferably 1.5 times.

  After forming irregularities in the polycarbodiimide layer, it is preferable to further heat at a temperature of about 120 to 200 ° C. for about 1 to 5 hours in order to completely cure the polycarbodiimide in the layer.

  The semiconductor light-emitting element obtained as described above is cut into individual semiconductor light-emitting elements using, for example, a dicing apparatus.

  By manufacturing the semiconductor light emitting element as described above, it is possible to prevent the semiconductor light emitting element from being damaged when the unevenness is formed, and to obtain a semiconductor light emitting element with high light extraction efficiency.

  In addition, as a manufacturing method of this invention, after laminating | stacking a polycarbodiimide layer on a semiconductor layer as mentioned above, the method of forming an unevenness | corrugation in a polycarbodiimide layer is also mentioned, However, The polycarbodiimide layer by which the unevenness | corrugation was formed previously is also mentioned. A method of stacking on a semiconductor layer is also encompassed by the present invention.

  The semiconductor light emitting device manufactured by the manufacturing method of the present invention is used for manufacturing a light emitting diode (LED) according to a known method. For example, when manufacturing a bullet-type LED, a semiconductor light-emitting element is bonded to the flat part in the cup as a function of the reflector with a silver paste or the like, and then wire bonding is performed using a gold wire between the electrode terminal and the lead frame. Connect. Thereafter, a bullet-type LED is manufactured by resin sealing with a conventionally used epoxy resin by transfer molding or the like.

  Next, although an Example demonstrates this invention concretely, this invention is not limited only to the said Example.

  In the following, all synthesis reactions were carried out under a nitrogen stream. The IR measurement was performed using FT / IR-230 (manufactured by JASCO Corporation).

Production Example 1 Production of polycarbodiimide 29.89 g of tolylene diisocyanate (isomer mixture: T-80 manufactured by Mitsui Takeda Chemical Co., Ltd.) in a 500 mL four-necked flask equipped with a stirring device, a dropping funnel, a reflux condenser, and a thermometer. 171.6 mmol), 94.48 g (377.52 mmol) of 4,4′-diphenylmethane diisocyanate, 64.92 g (308.88 mmol) of naphthalene diisocyanate, and 184.59 g of toluene were mixed.

  Further, 8.71 g (51.48 mmol) of 1-naphthyl isocyanate and 0.82 g (4.29 mmol) of 3-methyl-1-phenyl-2-phospholene-2-oxide were added and the temperature was raised to 100 ° C. with stirring. Warm and hold for 2 hours.

  The end point of the reaction was confirmed by IR measurement, and the reaction solution was cooled to room temperature to obtain a polycarbodiimide solution. In addition, 100 mol% of the diisocyanate residue of polycarbodiimide was an aromatic diisocyanate residue. Moreover, n in the said Formula (1) was distributed by 15-77.

  The obtained polycarbodiimide solution was diluted with cyclohexanone so that the solid content was 20% by weight to prepare a solution, and titanium oxide (average particle diameter: 100 nm, manufactured by Dainippon Ink Co., Ltd.) was added and titanium oxide was dispersed to obtain a polycarbodiimide coating solution. It was 75 mPa * s when the viscosity was measured using the viscometer (the Tokimec company make: EC-100S).

  The obtained coating solution was applied to a glass substrate by spin coating, dried at 150 ° C. for 1 hour to form a 2 μm-thick polycarbodiimide layer, and a spectrophotometer (manufactured by Hitachi, Ltd .: V-3000) was used. When the refractive index was measured at a wavelength of 550 nm and a temperature of 25 ° C., it was 2.05, and the elastic modulus at 150 ° C. was measured using a viscoelasticity measuring device (manufactured by Seiko Instruments Inc .: DMS120). there were.

Production Example 2 Production of Polycarbodiimide Sheet The polycarbodiimide solution obtained in Production Example 1 was coated on a separator (thickness 50 μm) (made by Toray Industries, Inc.) made of polyethylene terephthalate treated with a release agent (fluorinated silicone). This was heated at 130 ° C. for 1 minute and then heated at 150 ° C. for 1 minute to remove the separator and obtain a temporarily cured polycarbodiimide sheet (thickness 20 μm).

Example 1 Production of a semiconductor light emitting device

  An element (diameter 100 mm, thickness 100 μm) in which a GaN layer was formed on a sapphire wafer substrate and an electrode (gold electrode) was formed on the GaN layer was prepared.

  The coating liquid produced in Production Example 1 was applied to the surface of the device by spin coating (5000 rpm, 60 seconds) and dried at 120 ° C. for 30 minutes using a non-air dryer to form a polycarbodiimide layer having a thickness of 2 μm. Formed.

  Next, a nickel mold (110 mm × 110 mm) having hemispherical recesses with a width of 4 μm and a height of 2 μm as shown in FIG. 2 at a pitch of 6 μm was prepared.

  As shown in FIG. 3, the mold 6 and the semiconductor light emitting device are set on a hot press plate 7 of a pressure type vacuum laminator (manufactured by Nichigo Morton: V130), and the surface of the polycarbodiimide layer 3 at 150 ° C. and 0.3 MPa. Were heated and pressurized for 1 minute to form irregularities.

  Next, a resist mask was formed on the polycarbodiimide layer, the polycarbodiimide layer on the electrode was removed by RIE, and the electrode 4 was exposed.

  Thereafter, in order to completely cure the polycarbodiimide in the polycarbodiimide layer, the semiconductor light emitting device was further heated at 175 ° C. for 5 hours. Next, the semiconductor light emitting element was cut into a size of 0.4 mm × 0.4 mm with a dicer to obtain individual semiconductor light emitting elements.

Example 2 Production of Semiconductor Light-Emitting Element An element (diameter: 100 mm, thickness: 100 μm) in which a GaN layer was formed on a sapphire wafer substrate and an electrode (gold electrode) was formed on the GaN layer was prepared.

  The polycarbodiimide sheet prepared in Production Example 2 is placed on the surface of the element on the surface where the GaN layer and the electrode of the semiconductor light emitting element are formed to form a polycarbodiimide layer, and then the same nickel mold as in Example 1 is stacked. Then, by applying pressure / pressure laminator (manufactured by Nichigo Morton: V130) at 150 ° C., 0.3 MPa for 1 minute, the polycarbodiimide sheet layer is adhered to the semiconductor light emitting element surface and the polycarbodiimide sheet layer is Irregularities were formed on the surface.

  Next, a resist mask was formed on the polycarbodiimide layer, the polycarbodiimide layer on the electrode was removed by RIE, and the electrode 4 was exposed.

  Thereafter, in order to completely cure the polycarbodiimide in the polycarbodiimide layer, the semiconductor light emitting device was further heated at 175 ° C. for 5 hours. Next, the semiconductor light emitting element was cut into a size of 0.4 mm × 0.4 mm with a dicer to obtain individual semiconductor light emitting elements.

Comparative Example 1
Using the polycarbodiimide coating solution produced in Production Example 1, a semiconductor element was produced in the same manner as in Example 1 except that the unevenness was not formed on the polycarbodiimide layer.

Comparative Example 2
A polyimide solution (manufactured by Nitto Denko Corporation: JR-200) was applied to a glass substrate by spin coating, dried at 150 ° C. for 1 hour to form a polyimide layer having a thickness of 2 μm, and a spectrophotometer (manufactured by Hitachi, Ltd .: V-3000) was used to measure the refractive index at a wavelength of 550 nm and a temperature of 25 ° C., which was 1.68, and the elastic modulus at 150 ° C. was measured using a viscoelasticity measuring device (Seiko Instruments Inc .: DMS120). , 23 GPa.

  An attempt was made to produce a semiconductor element using a polyimide solution under the same pressure and temperature conditions as in Example 1, but the polyimide layer could not be formed with irregularities, and a semiconductor element was produced with irregularities on the polyimide layer. I couldn't.

Test Example A semiconductor light-emitting device obtained in Example 1, Example 2 and Comparative Example 1, and a semiconductor light-emitting device not subjected to unevenness processing in Comparative Example 2 were silver-based on a thermoplastic resin in a lead frame with a cup. The paste was mounted on the cup portion and fixed by heat drying. Thereafter, a gold wire was used, and the semiconductor light emitting element electrode portion and the lead frame were connected to each other by a wire bonder. Thereafter, a bullet-type LED sealing molding cup was used, and it was sealed into a bullet-shaped shape with an epoxy resin to obtain a bullet-type LED. The obtained bullet-type LED was energized and the amount of luminescence was measured. The amount of luminescence was measured by using an integrating sphere and measuring the amount of total luminescence with MCPD-3000 (manufactured by Otsuka Electronics Co., Ltd.). The results are shown in Table 1.

  Based on the above results, an LED manufactured using a semiconductor light emitting device in which a polycarbodiimide layer is laminated on a semiconductor layer and unevenness is formed on the polycarbodiimide layer is an LED manufactured using the semiconductor light emitting device of the comparative example. In contrast to this, an increase in the amount of light emission is observed, indicating that the light extraction efficiency is high.

  The manufacturing method of this invention can be utilized for manufacture of the semiconductor light-emitting device used for light emitting diodes, such as a bullet-type LED.

It is sectional drawing of the one aspect | mode of the semiconductor light-emitting device manufactured by the manufacturing method of this invention. It is sectional drawing of the one aspect | mode of the metal mold | die used for the manufacturing method of this invention. It is a figure which shows the formation process of the unevenness | corrugation in the manufacturing method of this invention.

Explanation of symbols

1 Substrate 2 Semiconductor layer 3 Polycarbodiimide layer 4 Electrode 5 Electrode 6 Mold 7 Hot press plate

Claims (4)

(1) A method for manufacturing a semiconductor light emitting device, comprising: laminating a layer containing polycarbodiimide on the light extraction surface side of the semiconductor light emitting device; and (2) forming irregularities on the layer containing polycarbodiimide. The polycarbodiimide has the general formula (1):

(Wherein R represents a diisocyanate residue, R ¹ represents a monoisocyanate residue, and n is an integer of 1 to 100)
The method of manufacturing a semiconductor light emitting device according to claim 1, wherein   The method of manufacturing a semiconductor light-emitting element according to claim 1, wherein a thickness of the polycarbodiimide layer before formation of irregularities is 0.5 to 30 μm.   The method of manufacturing a semiconductor light-emitting element according to claim 1, wherein a thickness of the polycarbodiimide layer before formation of irregularities is 0.5 to 10 μm.

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