TW201517304A - Pattern substrate with light-cone structures and method for manufacturing the same - Google Patents

Abstract

The invention relates to a pattern substrate with light-cone structures and a method for manufacturing the same. Primarily, it comprises a substrate, a plurality of light cones, and a thin film of group III nitride. A plurality of conical light cones having lower refractive index than substrate are formed on the substrate with lithography and dry etching process, and then they are uniformly covered with a thin film of group III nitride to form a pattern substrate with light-cone structures suitable for LED. Accordingly, in accordance with the non-planarity of the light cones formed on the substrate and the buffer characteristic of the thin film of group III nitride, a light extraction efficiency of LED and a dislocation caused by lattice mismatch can be improved to effectively increase the yield of subsequent epitaxial process.

Description

Graphic substrate with light-transmissive cone structure and manufacturing method thereof

The invention relates to a patterned substrate with a light-transmissive cone structure and a manufacturing method thereof, in particular to an improved substrate suitable for a light-emitting diode, which can change the light traveling by the light-transmissive cone structure on the surface of the substrate. The direction converges the light angle to increase the directivity of the light, and effectively achieves the light extraction efficiency of the light-emitting diode.

In recent years, the application of III-Nitride High Brightness Light Emission Diode (HB-LED) has become more and more widely used and has been widely used in traffic signs and LCDs. The backlight of the display, as well as various illuminations, are important components in daily life; because of its small size, no mercury pollution, high luminous efficiency, and long life, especially the wavelength of the light covers almost visible light. The range makes it a highly promising light-emitting diode material.

A conventional III-nitride light-emitting diode structure is formed by sequentially forming an n-type semiconductor layer, an active light-emitting layer, and a p-type semiconductor layer on a substrate, and in order to improve the current spreading effect of the device. And improving the light extraction efficiency, generally a transparent conductive layer, such as Indium Tin Oxide (ITO), is finally disposed on the p-type semiconductor layer, and finally, on the p-type semiconductor layer and the n-type semiconductor layer. A p-type electrode pad and an n-type electrode pad are respectively disposed, and the p-type electrode pad and the n-type electrode pad are respectively in ohmic contact with the p-type semiconductor layer and the n-type semiconductor layer, and in the ideal light-emitting diode When the carriers in the active light-emitting layer are combined into photons, if the photons are all radiated to the outside, the luminous efficiency of the light-emitting diode is 100%. However, when the light-emitting diode is actually implemented, the active light is emitted. The photons generated by the layer may not be transmitted to the outside world with 100% luminous efficiency due to various loss mechanisms.

For example, a gallium nitride light emitting diode (GaN LED) is grown on a sapphire substrate in an epitaxial manner due to the lattice constant of the epitaxial gallium nitride and the bottom sapphire substrate (Lattice Constant) and the coefficient of thermal expansion (CTE) are very different, so it will cause misfit Dislocation. Some of the misalignment will extend to the crystal surface, which is called Thread Dislocation. ), the value can reach 108 ~ 1010 / cm 2 , such high density difference will lead to poor crystal quality of the active light-emitting layer, thus reducing the internal quantum efficiency of the GaN LED, thereby reducing its luminance and generating heat, making GaN The temperature of the LED rises, affecting its luminous efficiency; therefore, the above There is an optical diode on factors such as: a current congestion (current crowding) or dislocation defects (dislocations), etc., affect the luminous efficiency.

Theoretically, the luminous efficiency of a light-emitting diode depends on external quantum efficiency, internal quantum efficiency, and light extraction efficiency; the so-called internal quantum efficiency is determined by material properties and material quality, and the light extraction efficiency is from the inside of the component. The proportion of radiation emitted to the surrounding air, the light extraction efficiency is dependent on the loss that occurs when the radiation leaves the inside of the element, one of the main causes of the above loss is due to the high refractive index of the semiconductor material forming the surface layer of the element, resulting in light The surface of the material produces Total Internal Reflection and cannot be emitted. For example, in the case of a semiconductor with high refractive index, the critical angle is very small. When the refractive index is 3.3, the total internal reflection angle is about Only 17 degrees, so most of the light emitted from the active light-emitting layer will be trapped inside the semiconductor; if the light extraction efficiency can be improved, the external quantum efficiency of the semiconductor light-emitting element will also increase; internal Sub-efficiency and light extraction efficiency have been developed in recent years, such as the use of indium tin oxide (ITO) as a current transport layer, Flip-chip, and a patterned sapphire substrate (Pattern Sapphire Substrate) , referred to as PSS), and the use of Current Block Layer (CBL), etc., so that the crystal quality of the active light-emitting layer of the light-emitting diode caused by the reduction of the through-type difference is effectively achieved, and the light-emitting diode is The decrease in illuminance caused by insufficient directivity is still a problem that system developers and researchers of illuminating diodes need to continuously overcome and solve.

Nowadays, the inventor is in view of the fact that the above-mentioned light-emitting diode element has many defects such as poor crystal quality of the active light-emitting layer and insufficient light directivity, and thus is a tireless spirit and borrows It is improved by its rich professional knowledge and years of practical experience, and the present invention has been developed based on this.

The main object of the present invention is to provide a patterned substrate with a light-transmissive cone structure and a manufacturing method thereof, and more particularly to an improved substrate suitable for a light-emitting diode, which can be changed by a light-transmitting cone structure on the surface of the substrate. The direction of travel and convergence of the light angle to increase the directivity of the light, effectively improving the light extraction efficiency of the light-emitting diode.

In order to achieve the above-mentioned implementation, the inventors have proposed a patterned substrate having a light-transmissive cone structure, comprising a substrate, a plurality of light-transmitting cones, and a group III nitride film; the material of the substrate is selected from the group consisting of sapphire and tantalum carbide , bismuth, gallium arsenide, zinc oxide, and a material having a hexagonal system of crystalline materials; a plurality of light-transmissive cones formed of a light-transmissive material formed on the surface of the substrate, wherein The refractive index of the light transmissive material is lower than that of the substrate; the III nitride film is coated on the light transmitting cone by vapor deposition or sputtering.

In one embodiment of the present invention, the material of the light-transmitting cone is formed from a material selected from the group consisting of cerium oxide, cerium oxynitride, and magnesium fluoride, and the heat-resistant temperature of the material of the light-transmitting cone is not Less than 1000 ° C.

In one embodiment of the present invention, the material of the light transmitting cone may also be composed of a group consisting of a low refractive index dielectric layer formed on the surface of the substrate and a low refractive index dielectric layer formed on the substrate. a high refractive index dielectric layer on the surface, a low refractive index dielectric layer formed on the surface of the substrate, and a metal reflective layer formed on the surface of the dielectric layer.

In an embodiment of the invention, the light transmission cone has a bottom surface connected to the surface of the substrate, and a height from the bottom surface to the top of the light transmission cone, wherein the ratio of the height to the maximum width of the bottom surface is not less than 0.6. Moreover, the light-transmitting cones are periodically distributed, and the adjacent light-transmitting cones have the same distance, and the pitch is not more than 1 micrometer.

In one embodiment of the present invention, the group III nitride film is formed from a material selected from the group consisting of aluminum nitride and gallium nitride, and has a thickness of between 100 angstroms (Angstron) and 1000 angstroms. .

In addition, in order to achieve the purpose of implementing a patterned substrate having a light-transmissive cone structure, the inventors have studied the following implementation techniques. First, a light-transmitting layer and a photoresist layer are sequentially formed on a substrate, wherein the light-transmitting layer is formed. It is composed of a light transmissive material having a lower refractive index than the substrate; secondly, a mask pattern is developed on the photoresist layer using a photolithography process; further, a mask pattern is used as a mask, and a dry etching process is used. The light transmissive layer forms a plurality of light-transmitting cones which are periodically spaced apart from each other and have a tapered shape; and subsequently, the photoresist layer of the mask pattern is removed by photoresist removal; and then, electron gun vacuum evaporation (Electron-Gun Evaporation) is performed. A group III nitride film is correspondingly coated on the light-transmitting cone by evaporation or sputtering; finally, the patterned substrate is heated by a high-temperature tempering process to complete the method for fabricating the patterned substrate with the light-transmissive cone structure.

In an embodiment of the present invention, the electron gun vacuum evaporation method is to impinge on the target of the group III element with nitrogen plasma, and to cause the group III nitride particles to be sputtered at a temperature of not lower than 600 ° C. Covered on the light-transmitting cone.

In one embodiment of the invention, the Group III nitride film has a thickness between 100 Angstroms and 1000 Angstroms.

In an embodiment of the invention, the high temperature tempering process uses one of a rapid thermal processing (RTP) and a high temperature furnace (Furnace) process, not less than 1000 ° C. The temperature corrects the properties and process results of the Group III nitride film.

Therefore, the present invention reduces the light emission of the active light-emitting layer of the subsequently prepared light-emitting diode by forming a plurality of light-conducting cones having a conical shape and a lower refractive index than the substrate on the surface of the substrate to achieve non-flatness of the surface of the substrate. The total reflection angle, and the difference in refractive index between the light-transmitting cone and the substrate, so that the light emitted by the light-emitting diode contacts the light-transmitting cone and the substrate, and effectively enhances the light-emitting diode through secondary refraction and reflection. In addition, the present invention can control the light-transmitting cone to have a conical shape, so that the active light-emitting layer from the light-emitting diode emits light toward the substrate, after contacting the light-transmitting cone and the substrate, The light extraction efficiency of the light-emitting diode is effectively improved by the secondary refraction and reflection, and the light extraction efficiency of the light-emitting diode obtained by etching the substrate to obtain the epitaxial substrate having the roughened structure is known. In contrast, the light extraction efficiency of the light-emitting diode having the light-transmitting cone of the present invention can be improved by about 20%; further, the light-transmitting cone of the present invention is etched on the substrate via an anisotropic dry etching process. The optical layer is prepared, has a simple process, and is easier to control the size, density and uniformity of the light-transmitting cone, thereby effectively improving the light-emitting uniformity of the light-emitting diode; finally, the present invention improves the conventional substrate by the III-nitride film. And the misalignment phenomenon caused by the lattice mismatch between the epitaxial films of the subsequent light-emitting diodes can effectively reduce the difference density, avoiding the abnormal phenomena such as stress accumulation and misalignment, and effectively increasing the subsequent epitaxy. The luminous efficiency of the process, and the combination of the group III nitride film and the light-transmitting cone, the light extraction efficiency and the light-emitting diode having only the light-transmitting cone can be increased by about 15% to 20%.

(1)‧‧‧Substrate (2)‧‧‧Lighting cone

(21) ‧ ‧ bottom (22) ‧ ‧ height

(200)‧‧‧Transparent layer (3)‧‧‧III nitride film

(4) ‧ ‧ photoresist layer (41) ‧ ‧ mask pattern

(400) ‧‧‧Photomask (5)‧‧‧n type semiconductor layer

(S1) ‧ ‧ Step 1 (S2) ‧ ‧ Step 2

(S3) ‧ ‧ Step 3 (S4) ‧ ‧ Step 4

(S5) ‧ ‧ Step 5 (S6) ‧ ‧ Step 6

(W) ‧ ‧ Width (H) ‧ ‧ height

(S) ‧ ‧ spacing (P) ‧ ‧ pitch

First: a schematic cross-sectional view of a patterned substrate of a preferred embodiment of the present invention

The second figure: a schematic diagram of a light-transmissive cone of a preferred embodiment of the present invention

FIG. 3(A) and FIG. 3(B) are comparative diagrams of scanning electron micrographs of a nitride nitride film of a preferred embodiment of the present invention.

Fourth: Flow chart of steps of a method for manufacturing a patterned substrate with a light-transmissive cone structure of the present invention

Fig. 5 is a flow chart showing the steps of the method for manufacturing a patterned substrate having a light-transmissive cone structure of the present invention

The object of the present invention and its structural design and advantages will be apparent from the following detailed description of the preferred embodiments.

In the following description of the embodiments, it should be understood that when a layer (or film) or a structure is disposed on another substrate, another layer (or film), or another structure "on" or "down", "Directly" is located on another substrate, layer (or film), or another structure, or more than one intermediate layer between the two is disposed in an "indirect" manner. The reviewer may describe the location of each layer with reference to the drawings.

Referring to the first figure, a schematic cross-sectional view of a patterned substrate of a preferred embodiment of the present invention has a transparent substrate structure, including:

a substrate (1);

a plurality of light-transmitting cones (2) formed by a tapered body made of a light-transmitting material on a surface of the substrate (1), wherein the light-transmitting material has a lower refractive index than the substrate (1);

A group III nitride film (3) is coated on the light-transmitting cone (2) by vapor deposition or sputtering.

In addition, please refer to the second figure, which is an enlarged schematic view of a light-transmissive cone of a preferred embodiment of the patterned substrate with a light-transmissive cone structure, wherein the material of the light-transmitting cone (2) is selected from the group consisting of yttrium oxide ( a material of a group consisting of SiO x ), yttrium oxynitride (SiON x ), and magnesium fluoride (MgF 2 ), and the heat-resistant temperature of the light-transmitting cone (2) is not less than 1000 ° C to withstand The film deposition high temperature in the subsequent light-emitting diode film forming process; the light-transmitting cone (2) has a bottom surface (21) connected to the surface of the substrate (1), the bottom surface (21) has a width W, and The height (22) from the bottom surface (21) to the top of the light-transmitting cone (2) is denoted by H. When the ratio of the height (22) of the light-transmitting cone (2) to the width of the bottom surface (21) is too small, the light-transmitting cone (2) The height (22) is insufficient to cause the incident angle of the light to contact the light-transmitting cone (2) to be too large to reduce the light extraction efficiency. Therefore, the preferred embodiment of the present invention is designed to have the height of the light-transmitting cone (2). (2 The ratio (H∕W) to the maximum width of the bottom surface (21) is not less than 0.6, and the optimum ratio is between 0.61 and 0.65. Therefore, the light transmission cone can be controlled by 2) The conical design makes it easier to change the path of light after contacting the light-transmitting cone (2), thereby improving the light extraction efficiency of the light-emitting diode. The main purpose is to make the active light-emitting layer from the light-emitting diode ( The light emitted toward the substrate (1), after contacting the light-transmitting cone (2) and the substrate (1), can be substantially emitted outward after secondary refraction and reflection, thereby effectively enhancing the light-emitting diode. The light extraction efficiency is compared with the light extraction efficiency of the light-emitting diode obtained by etching the substrate to obtain the epitaxial substrate having the roughened structure, and the light-emitting diode of the present invention has the light-emitting diode (2) The extraction efficiency can be increased by about 20%; in addition, the two adjacent light-transmitting cones (2) are not connected to each other and are periodically distributed, and the substrate (1) can be adjusted by the distance between the light-transmitting cones (2). Larger in unit area The light-transmitting cone (2) density, to achieve better reflection and refraction effect, the two adjacent light-transmitting cones (2) spacing S of the preferred embodiment of the present invention is no more than 1 micrometer, and two light-transmitting cones ( 2) The distance between the tops has the same pitch P (Pitch) of 3 microns, however, it must be noted that the pitch of the above-mentioned light-transmitting cones (2) is 3 micrometers, which is a preferred embodiment for convenience of description, rather than It is to be understood by the example, and those skilled in the art know that the pitch of the light-transmitting cone (2) of the present invention may have different pitch ranges due to the characteristics of the solar cell and the process conditions, and does not affect the present invention. The actual implementation.

Furthermore, the material of the light-transmitting cone (2) may also be composed of the following group: a low-refractive-index dielectric layer (not shown) formed on the surface of the substrate (1), and a layer formed thereon a high refractive index dielectric layer (not shown) on the surface of the low refractive index dielectric layer, a low refractive index dielectric layer (not shown) formed on the surface of the substrate (1), and a dielectric layer formed on the substrate a metal reflective layer (not shown) of the surface of the layer, that is, in another preferred embodiment of the present invention, the light-transmitting cone (2) can be formed by a type of cerium oxide (SiO 2 ) formed on the surface of the substrate (1). a layer consisting of a layer of zinc dioxide (TiO 2 ) formed in the ceria layer, the ceria layer and the zinc dioxide layer functioning as a Distributed Bragg Reflector (DBR), In order to cause reflection of photons, the light extraction efficiency of the light-emitting diode is effectively improved.

Furthermore, the substrate (1) used in the present invention is selected from the group consisting of sapphire (Al 2 O 3 ), tantalum carbide (SiC), bismuth (Si), gallium arsenide (GaAs), zinc oxide (ZnO), and Formed with one of a group of Hexagonal crystalline materials; it is worth noting that when the substrate (1) is formed of sapphire, and the light-transmitting cone (2) is different from the substrate (1) When the material is formed, for example, the preferred material of the light-transmitting cone (2) is cerium oxide (SiO 2 ), a contact surface of the substrate (1) and the light-transmitting cone (2) may be formed with a void structure. Such a structure can increase the degree of light scattering, thereby improving the light extraction efficiency of the light-emitting diode element.

Further, the group III nitride film (3) is formed by one material selected from the group consisting of aluminum nitride (AlN) and gallium nitride (GaN), and the group III nitride film (3) of the present invention is more The preferred embodiment is a film of aluminum nitride. If the thickness of the aluminum nitride is less than 100 angstroms, the aluminum nitride may be in the form of particles and cannot form an effective film. If the thickness of the aluminum nitride is more than 1000 angstroms, then In the case of a light-emitting diode film formation process, cracks are likely to occur. Therefore, the optimum thickness of the group III nitride film (3) is between 100 angstroms and 1000 angstroms; further, please refer to the third figure (A). And (B) is a comparative diagram of a Group III nitride thin film scanning electron microscope (SEM) according to a preferred embodiment of the patterned substrate having a light-transmissive cone structure, wherein the present invention A preferred embodiment of the Group III nitride film (3) is a film of aluminum nitride (AlN), and a light-transmitting cone (2) The embodiment is cerium oxide (SiO 2 ), and the third figure (A) is a partial SEM photograph of a conventional luminescent diode without a group III nitride film (3), and the third figure (B) is Partial SEM photograph of a light-emitting diode of a group III nitride film (3) of aluminum nitride, comprising a light-transmitting cone (2) and a light-emitting diode n-type semiconductor layer (5), a preferred embodiment of N-GaN The interface between the two shows that the light-emitting diode having the aluminum nitride film structure has a flat and dense interface characteristic, which can effectively improve the light extraction efficiency of the light-emitting diode, and therefore, has a group III nitride film according to the present invention (3). The light-emitting diode composed of the light-transmitting cone (2) can increase the light extraction efficiency by about 15% to 20% compared with the light-emitting diode having only the light-transmitting cone (2); The light-transmitting cone (2) disposed under the group III nitride film (3) under aluminum nitride (AlN) is made of cerium oxide (SiO 2 ), which is a preferred embodiment for convenience of description. Not in this case And the skilled artisan knows that the light-transmitting cone (2) constituent material of the present invention may be formed by one of a group consisting of cerium oxynitride (SiON x ) or magnesium fluoride (MgF 2 ), or A decentralized Bragg mirror (DBR) structure composed of cerium oxide (SiO 2 ) and zinc dioxide (TiO 2 ) does not affect the actual implementation of the present invention.

In order to enable the reviewing committee to have a more in-depth and specific understanding of the present invention, please refer to the fourth and fifth figures, which are schematic flowcharts of the steps and steps of the method for manufacturing the patterned substrate with the light-transmitting cone structure of the present invention. Including the following steps:

Step 1 (S1): sequentially forming a light transmissive layer (200) and a photoresist layer (4) on a substrate (1), wherein the light transmissive layer (200) has a lower refractive index than the substrate (1) The light-transmitting material is formed of, for example, one of a group consisting of yttrium oxide (SiO x ), yttrium oxynitride (SiON x ), and magnesium fluoride (MgF 2 ), and is used for the subsequent light-emitting diode. In the film forming high temperature process, the light transmissive layer (200) is preferably selected from materials having a heat resistance of not less than 1000 ° C. In addition, the photoresist layer (4) may be selected from a positive photoresist or a negative photoresist material according to the requirements of the process. Wait for one of them;

Step 2 (S2): developing a mask pattern (41) on the photoresist layer (4) by using a photolithography process; wherein the photolithography process is combined with a photomask (400) having a predetermined pattern. The predetermined portion of the photoresist layer (4) is removed by a lithography process, so that the residual photoresist layer (4) forms a mask pattern (41), so that the light-transmissive layer (200) covered by the photoresist-free layer (4) is not covered. Naked

Step 3 (S3): using a mask pattern (41) as a mask, using a dry etching process to form a plurality of light-transmitting cones (2) which are periodically spaced apart from each other and have a tapered shape in the light-transmitting layer (200); wherein the dry etching is performed It is a radio frequency power between 200 watts and 400 watts, and is a fluorine-containing gas such as carbon tetrafluoride (CF 4 ), sulfur hexafluoride (SF 6 ), and trifluoromethane (CHF 3 ). The non-isotropic etching etches the light transmissive layer (200) to form the light transmissive layer (200) into a plurality of conical light-conducting cones (2), which are dry-etched on the substrate in accordance with a preferred embodiment of the present invention ( 1) the etching selectivity ratio of the light transmissive layer (200) is between 1:0.5 and 1:1.5;

Step 4 (S4): removing the photoresist layer (4) of the mask pattern (41) by using a photoresist removal method;

Step 5 (S5): coating a group III nitride film (3) correspondingly on the light-transmitting cone (2) by electron gun vacuum evaporation evaporation or sputtering;

Step 6 (S6): heating the patterned substrate using a high temperature tempering process to complete the method of fabricating the patterned substrate having the light transmissive cone (2) structure.

In addition, before the photoresist layer (4) is formed in the first step (S1), a high refractive index dielectric layer (not shown) or a metal reflective layer may be further formed on the surface of the light transmissive layer (200) (not shown) One of them plays the role of a decentralized Bragg reflector (DBR), which causes reflection of photons, effectively improving the light extraction efficiency of the light-emitting diode.

In addition, the electron gun vacuum evaporation method is to impinge the group III nitride particles on the light-transmitting cone (2) by spraying the target of the group III element with nitrogen plasma at a temperature of not lower than 600 ° C; The preferred embodiment of the present invention uses an electron gun vacuum evaporation method to deposit an aluminum nitride film of 100 angstroms to 1000 angstroms on a light-transmitting cone (2) composed of a cerium oxide component, because an electron gun vacuum evaporation method can be used. The aluminum nitride film is evenly and completely covered on the light-transmitting cone (2). The present invention is capable of buffering the light-transmitting cone (2) and the subsequent light-emitting diode film by a thin group III nitride film (3). The lattice difference between the n-type semiconductor layers (5) in the process effectively reduces the difference in the discharge density, so as to avoid the occurrence of abnormalities such as stress accumulation and misfit dislocation, and effectively increase the yield of the subsequent epitaxial process; In addition, the above description refers to the distance S between the light-transmitting cones (2) being no more than 1 micrometer. In the preferred embodiment of the invention, the pitch of the two light-transmitting cones (2) is P. 3 micrometers, when the width of the light-transmitting cone (2) is 2.8 micrometers to 2.9 micrometers, the spacing S is 0.2 micrometers to 0.1 micrometers. Therefore, the present invention uses an electron gun vacuum evaporation method to steam. The plated III nitride film (3) has a good Gap Filling Ability, which can effectively fill the minimum pitch of the light-transmitting cone (2) to improve the extraction efficiency of light, however, it must be noted that The pitch of the light-transmitting cone (2) is 3 micrometers, which is a preferred embodiment for convenience of description, and is not limited to the example, and those skilled in the art will know the light-transmitting cone (2) section of the present invention. The distance may vary depending on the characteristics of the solar cell and the process conditions, and does not affect the actual implementation of the present invention.

Furthermore, the high-temperature tempering process can use one of the methods of rapid high-temperature treatment and high-temperature furnace control to correct the group III nitrogen prepared by vapor deposition or sputtering of the electron gun by vacuum evaporation at a temperature of not less than 1000 ° C. Film properties and process results of the film (3).

It can be seen from the above description that the patterned substrate with the light-transmitting cone structure of the present invention and the manufacturing method thereof have the following advantages compared with the prior art:

1. The patterned substrate with a light-transmissive cone structure of the present invention and a method for fabricating the same are characterized in that a plurality of conical cones having a conical shape and a refractive index lower than that of the substrate are formed on the surface of the substrate to achieve non-flatness of the surface of the substrate. The total reflection angle of the light emitted by the active light-emitting layer of the subsequently prepared light-emitting diode, and the difference in refractive index between the light-transmitting cone and the substrate is used to make the light emitted by the light-emitting diode contact the light-transmitting cone and the substrate through the second The secondary refraction and reflection function effectively improve the light extraction efficiency of the light-emitting diode.

2. The patterned substrate with the light-transmissive cone structure of the present invention and the manufacturing method thereof are designed to control the light-transmitting cone to have a conical shape, so that the active light-emitting layer from the light-emitting diode emits light, and the light traveling toward the substrate is in contact with After the light cone and the substrate can be substantially outwardly emitted through the secondary refraction and reflection, the light extraction efficiency of the light-emitting diode is effectively improved, and the light obtained by the epitaxial substrate having the roughened structure is obtained by etching the substrate. Compared with the light extraction efficiency of the diode, the light extraction efficiency of the light-emitting diode having the light-transmitting cone can be improved by about 20%.

3. The patterned substrate with a light-transmissive cone structure of the present invention and the light-transmissive cone of the method for manufacturing the same are obtained by etching a light-transmitting layer on a substrate by an anisotropic dry etching process, which has a simple process and is easier to control. The size, density and uniformity of the light-transmitting cone effectively improve the light uniformity of the light-emitting diode.

4. The patterned substrate with the light-transmissive cone structure of the present invention and the method for fabricating the same are used to improve the misalignment caused by lattice mismatch between the epitaxial films of the conventional substrate and the subsequent light-emitting diode by the group III nitride film. Phenomenon, can effectively reduce the difference density, to avoid the accumulation of stress and misalignment, and effectively increase the yield of subsequent epitaxial process, and has a combination of a group III nitride film and a light-emitting cone The light extraction efficiency and the light-emitting diode having only a light-transmitting cone can be increased by about 15% to 20%.

In summary, the patterned substrate having the light-transmissive cone structure of the present invention and the method of manufacturing the same can achieve the intended use efficiency by the above-disclosed embodiments, and the present invention has not been disclosed before the application. Cheng has fully complied with the requirements and requirements of the Patent Law.爰Issuing an application for a patent for invention in accordance with the law, and asking for a review, and granting a patent, is truly sensible.

The illustrations and descriptions of the present invention are merely preferred embodiments of the present invention, and are not intended to limit the scope of the present invention; those skilled in the art, which are characterized by the scope of the present invention, Equivalent variations or modifications are considered to be within the scope of the design of the invention.

(1) ‧‧‧Substrate

(2) ‧ ‧ light cone

(3) ‧‧‧III nitride film

Claims (13)

A patterned substrate having a light-transmissive cone structure includes at least:
a substrate;
A plurality of light-transmitting cones are formed on the surface of the substrate by a cone-shaped body made of a light-transmitting material, and a group III nitride film is coated on the light-transmitting cone by vapor deposition or sputtering. The patterned substrate having a light-transmissive cone structure according to claim 1, wherein the light-transmitting cone material has a lower refractive index than the substrate, and is selected from the group consisting of cerium oxide, cerium oxynitride, and magnesium fluoride. Group of. The patterned substrate with a light-transmissive cone structure according to claim 1, wherein the material of the light-transmitting cone is composed of the following group: a low refractive index medium formed on the surface of the substrate. And an electrical layer and a high refractive index dielectric layer formed on the surface of the low refractive index dielectric layer, a low refractive index dielectric layer formed on the surface of the substrate, and a metal reflective layer formed on the surface of the dielectric layer. The patterned substrate with a light-transmissive cone structure according to claim 1, wherein the heat-resistant temperature of the material of the light-transmitting cone is not less than 1000 °C. The patterned substrate with a light-transmissive cone structure according to claim 1, wherein the light-transmitting cone has a bottom surface connected to the surface of the substrate, and a height from the bottom surface to the top of the light-transmitting cone. Wherein the ratio of the height to the maximum width of the bottom surface is not less than zero. 6. The patterned substrate with a light-transmissive cone structure according to claim 1, wherein the light-transmitting cone is periodically distributed, and two adjacent light-transmitting cones have the same distance, and the spacing is not greater than 1 micron. The patterned substrate having a light-transmissive cone structure according to claim 1, wherein the group III nitride film is selected from the group consisting of aluminum nitride and gallium nitride. The patterned substrate having a light-transmitting cone structure according to claim 1, wherein the group III nitride film has a thickness of between 100 angstroms and 1000 angstroms. A method for fabricating a patterned substrate having a light-transmissive cone structure, the steps of which include:
Step 1: sequentially forming a light transmissive layer and a photoresist layer on a substrate, wherein the light transmissive layer is composed of a light transmissive material having a lower refractive index than the substrate;
Step 2: using a photolithography process to develop a mask pattern on the photoresist layer;
Step 3: using the mask pattern as a mask, using a dry etching process to form a plurality of light-transmitting cones which are periodically spaced apart from each other and have a tapered shape;
Step 4: removing the photoresist layer of the mask pattern by using a photoresist removal method;
Step 5: correspondingly coating a group III nitride film on the light-transmitting cone by electron gun vacuum evaporation evaporation or sputtering; and step 6: heating the patterned substrate using a high-temperature tempering process to complete the tool A method for fabricating a patterned substrate of a light transmissive cone structure. The method for fabricating a patterned substrate having a light-transmissive cone structure according to claim 9, wherein a high-refractive-index dielectric layer or metal is further formed on the surface of the light-transmitting layer before the step of forming the photoresist layer. One of the reflective layers. The method for fabricating a patterned substrate having a light-transmitting cone structure according to claim 9, wherein the electron gun vacuum evaporation method is to impinge a target of a group III element with a nitrogen plasma to a temperature of not lower than 600 ° C. The group III nitride particles are sputter-coated on the light-transmitting cone. The method for fabricating a patterned substrate having a light-transmissive cone structure according to claim 9, wherein the group III nitride film has a thickness of between 100 angstroms and 1000 angstroms. The method for fabricating a patterned substrate having a light-transmitting cone structure according to claim 9, wherein the high-temperature tempering process uses one of a rapid high-temperature treatment and a high-temperature furnace tube, and is corrected at a temperature not lower than 1000 ° C. The properties and process results of the III-nitride film.