TW200814366A - Light emitting diode body with sub micron light correcting pillar and the method of making the same - Google Patents

Abstract

The invention provides a light emitting diode body with sub micron light correcting pillar and the method of making the same. The light emitting diode body includes: a planar substrate ; a quantum unit formed on the substrate for emitting light by the photo-electric effect; and two pieces of electrodes for providing electrical energy to the said quantum unit. During the patterning process for the mesa area, plural light correcting pillars rising straight upward from the first type cladding layer are etched deeply in the region of non-mesa area simultaneously. By the difference of diffraction indices between the light correction pillars with height of sub micron scale and the surrounding regions, the propagation direction for light emitted from the quantum unit through the side walls of mesa area can be changed to the upward direction. Therefore the brightness and light emitting area of light emitting diode body is increased.

Description

200814366 IX. Description of the Invention: [Technical Field of the Invention] θ The present invention relates to a solid-state light-emitting element and a method of manufacturing the same, and in particular to a light-emitting diode and a method of manufacturing the same. [Prior Art]

Since the solid-state light-emitting element has a low life span, a fast reaction rate, and one of the types of recognition rates, especially in the life of a light-emitting diode. The advantages of long life, power saving, small size, high driving, etc., are the new-generation light source that has been widely used in the surrounding common meals. Figure 2, the general 'light-emitting diode i contains _ block substrate i, at least A layer of insect crystals forms a quantum unit 该 on the substrate U, a layer of a pen layer 13, and two electrodes 14 that provide electrical energy. The block substrate 11 is composed of a lattice constant matching the quantum unit. For example, when the layer quantum unit 12 is a gallium nitride-based semi-conductive material, the block substrate n is Easy to epitaxial sapphire.

The layer of quantum cells 12 is formed from the top surface of the substrate u, and the diseased layer includes a bottom portion 124 connected to the substrate U and an extension portion 125 extending integrally from the central portion of the bottom plate 124. a cladding layer 121, a layer of active layer m formed from the top surface of the first type of cladding layer i2i, 125 (a layer formed from the top surface of the poetic layer 123) a coating layer 122, and a conductive layer 126 formed upward from the plastic cladding layer 122, the first and second type cladding layers 121, 122 form a quantum energy barrier with respect to the active layer 123 to generate light by photoelectric effect, and The extension portion 125 of the first type of cladding layer 121, the active layer 5 200814366 123, the second type cladding layer 122 and the conductive layer 126 constitute a mesa platform called the industry. The conductive layer 126 is transparent and can evenly distribute current. The material composition, such as indium tin oxide (known in the industry as ITO), allows the current to flow laterally and uniformly, thereby improving the efficiency of the first and second type of cladding layers 121, 122 and the active layer 123 to generate light by photoelectric effect. .

The two electrodes 14 are arranged diagonally opposite to each other, and one of the electrodes 14 is connected to the top corner of the bottom 124 of the first type of cladding layer 121 and is in ohmic contact with the first type of cladding layer 121. Another electrode 14 is connected to the conductive layer 126 and is in ohmic contact with the second type of cladding layer 122 via the conductive layer 126, and the quantum unit 12 can be supplied with electricity. When power is applied from the two electrodes 14 The current flows through the conductive > 126 laterally diffused and circulates, and generates light after passing through the first and second type cladding layers 122 and 122 and the active layer 123; the light generated by the quantum unit 12 is partially vertical from the mesa platform 100 The surface of the conductive layer i26 is emitted toward the positive direction, and the portion is emitted from the surface of the mesa. The amount of light, intensity, and brightness of the mesa platform 100 are sufficient, so the lateral light is added. Guide the fairy, let it waste; however, if you can effectively move the lateral light guide vertically forward, you can further increase the light-emitting diode! The inherent degree = (4) and (4) may also increase the luminous dipole (four) product.

SUMMARY OF THE INVENTION W 6 200814366 Therefore, it is an object of the present invention to provide a light-emitting diode having a high light-emitting luminance and a large light-emitting area. Moreover, another object of the present invention is to provide a method of manufacturing a light-emitting diode having high light-emitting luminance and a large light-emitting area. Thus, a light-emitting diode of the present invention having a sub-micron optical correction column comprises a substrate, a quantum unit, and two electrodes. The substrate is in the form of a plate. The 忒 layer quantum unit has a first type of cladding layer including a bottom portion connected to the substrate and an extending portion extending upward from a central portion of the bottom portion, and a layer extending from the top surface of the first type of cladding layer An active layer formed thereon, a second type of coating layer formed from a top surface of the active layer, and a plurality of light-correcting columns formed from a top surface of the bottom of the first type of coating layer, the first type of coating The layer forms a quantum energy barrier with respect to the active layer to generate light by a photoelectric effect, and the extension portion of the first type of the first layer and the active layer and the second type of slope layer together form a downward supply light from the top surface and The platform that is laterally emitted from the side surface, the difference in refractive index between the plurality of light-correcting columns and the surrounding medium changes the traveling direction of the light emitted laterally from the side of the platform, and can travel substantially in the forward direction. ▲The two electrodes are respectively placed on the top surface of the top layer of the top layer of the top layer of the top layer of the top layer of the top layer and the ohmic layer of the first and second type cladding layers respectively. The quantum unit can be supplied with electrical energy by contact. Further, the method for fabricating a light-emitting diode having a submicron optical correction column of the present invention comprises the following steps. Firstly, a quantum material having a first type of coating layer of 7 200814366, a second type of cladding layer, and an active layer between the first and second type cladding layers is formed upward from the semiconductor material from the plate-shaped substrate, and The first and second type batch layers form a quantum energy barrier with respect to the active layer and can generate light by a photoelectric effect, and then define a top surface of the quantum unit into a first electrode region, a ring = a central region of the first electrode region, and a block a second electrode region spaced from the central region, and an outer ring region surrounding the central region and the second electrode region.

8. Afterwards, a block depth is removed from the outer ring zone of the die unit to a block domain of the upper half of the first type of cladding layer, so that the structure corresponding to the outer ring zone is formed into a plurality of individual light Correction column, „, the structure that is reserved for the central area constitutes a platform for the internal photoelectric effect to be emitted from the top surface and from the side side. The light formed by the corresponding second electrode area is removed. Correcting the column. _ Finally, in the position corresponding to the first electrode region of the page of the quantum cell and the exposed top of the first type of cladding layer facing the second electrode region, the conductive material is divided into two electrodes. That is, the light-emitting diode having the sub-micron light-correcting column is obtained. The effect of the present invention is that in the process of patterning the mesa platform, the step of forming a plurality of roots rises from the bottom of the first type of coating layer. The light = column 'by the height of the sub-micron-scale light-corrected column and the refractive index difference of its surrounding mass' can be made corresponding to the side of the mesa platform: the direction of travel of light changes 'substantially vertical forward Travel, which in turn increases the p-pole The above-mentioned and other technical contents, features and effects of the present invention will be apparent from the following detailed description of the preferred embodiments of the accompanying drawings. Before the present invention is described in detail, it is noted that in the following description, 'like elements are denoted by the same reference numerals. " Referring to Figures 3 and 4, the present invention has a sub-micron optical correction column. A first preferred embodiment of the light-emitting diode 2 is a quantum unit 22 comprising a substrate 2, a layer of house crystals formed on the substrate 21, and two electrodes 23 for supplying electrical energy. The substrate 21 is formed of a material having a lattice constant matched with the quantum unit 22, and is formed into a plate shape. For example, when the quantum unit 22 is a gallium nitride-based semiconductor material, the substrate 21 is easy to be polished. Crystal sapphire. The quantum unit 22 has a layer 224 including a bottom portion 224 connected to the substrate 21 and an extension portion 25 extending upward from the central portion of the bottom portion 22, and a layer from the first type The active layer 223 formed by the top surface of the extension portion 225 of the cladding layer 225, a second type of cladding layer 222 formed from the top surface of the active layer 223, and a plurality of roots 224 from the bottom of the first type of the rear layer 221 The first and second type cladding layers 221 and 222 are formed into a quantum energy barrier with respect to the active layer 223 to generate light by a photoelectric effect, and the extension portion 225 of the first type cladding layer 221 and the active layer are formed. The first type of cladding layer 222 of the first type 223 forms a platform for the light to be emitted from the top surface and the side surface of the side surface (that is, the mesa platform referred to in the industry). Referring to FIG. 5 and FIG. 6, the average height of the plurality of light-correcting columns 3 is between 9 200814366 1x10-~2〇χ1〇-, and the average diameter is between 〇1χ1〇_7~9χΐ〇Λη, and the distribution density is Each of the optical correction columns 3 includes a section identical to that of the first-type cladding layer 221 and protrudes upwardly from the top surface of the bottom portion 224 of the first-type cladding layer 221 at 1 to 2·5χ103 (−2). The bottom section 31, the middle section 32 which is identical in structure to the active layer 223 and protrudes upward from the top surface of the bottom section 31, and the section structure is the same as that of the second type cladding layer 222 and The top section of the middle section 32 is upwardly convex, but is limited by the actual process (please be described later), and each of the light correction columns 3 may have only one or a portion of the bottom section 31, or Having a truncated bottom section 31 and a section of the complete/and or partial section 32, or having a truncated bottom section 31, a section of midsection 32 and a section of complete/and or partial section 33, however, regardless of the majority of the light Correcting the actual structure of the column 3, the difference in refractive index from the surrounding medium (i.e., air) may be from the extension 225 of the first type of cladding layer 221 The traveling direction of the lateral light emitted from the outer side of the platform side of the active layer 223 and the second type of cladding layer 222 is changed, and proceeds substantially in the forward direction. Referring to FIG. 3 and FIG. 4, the two electrodes 23 are relatively far away from each other. Diagonally arranged, wherein a piece of the electrode 23 is connected to a corner of the top surface of the bottom portion 224 of the first type of cladding layer 221, and is in ohmic contact with the first type of cladding layer 221, and the other electrode 23 is connected thereto. The corner of the top surface of the second type of cladding layer 222 is in ohmic contact with the second type of cladding layer 222, and the quantum unit 22 can be supplied with electrical energy. When electrical energy is applied from the two electrodes 23, the current dispersion flow passes. The quantum unit 22 causes the quantum unit 22 to generate photons by photoelectric effect, thereby causing the light-emitting diode 2 to emit light; the light generated by the quantum unit 22 is partially emitted from the 10 200814366 corresponding to the mesa platform 100; Corresponding to the (4) (10) side of the platform 100 side of the circumferential surface of the lateral light, and because the majority of the light repair iMi 3 # surrounding air medium to form an effect similar to the waveguide resonator cavity and path 'to make these lateral light According to the principle of spectroscopic refraction, the incident angle and the reflection angle are continuously modified in the cavity and the path, and finally the material is forwardly oriented in a direction perpendicular to the top surface of the A type; 222, so that the light emitting diode The light-emitting area of 2 not only includes the area corresponding to the top surface of the platform (10), but also increases the area of the top surface of the bottom portion 224 of the first type of cladding layer 221, and at the same time, the light-emitting brightness of the light-emitting diode 2 not only includes the original Corresponding to the positive light intensity emitted from the top surface of the mesa platform, and also increasing the brightness of the forward light which is originally directed to the lateral light but guided forward, see Figure 7, after comparison, the light is emitted The luminance of the polar body 2 is effectively increased by about 5/4 times or more under the conditions of different emission wavelengths. The above-described light-emitting diode 2 of the present invention having the sub-micron optical correction column 3 can be more clearly understood after the following description of the process. Referring to FIG. 8, when the above-mentioned light-emitting diode 2 is prepared, step 71 is first performed to form a first-type cladding layer 221 from a plate-shaped sapphire substrate 21 by a gallium nitride germanium semiconductor material. The layer 223 and the first type of cladding layer 222 are formed such that the first and second type cladding layers 221 and 222 form a quantum energy barrier with respect to the active layer 223 to form a dendrite unit 21 which can generate light by photoelectric effect, and then step 72 a first electrode region, a central region surrounding the first electrode region, and a second portion spaced from the central region are defined on a top surface of the quantum unit 21 (ie, a surface of the second layer of the resist layer 222) 11 200814366 - The block encircles the outer ring zone of the central zone and the second electrode zone. (10) One. After step-by-step 73, the yellow light lithography technique is applied to cover the central region of the quantum early 疋21 and the first and second electrode regions, and then the top surface of the outer ring region is face-to-face, except for the block depth to the _ type The block domain of the upper half of the blanket layer (2), the structure corresponding to the retained area of the j-cloth area is the light-correcting column of the plurality of roots, and the structure of the light-correcting column 3 5 constituting the remaining area of the central area is formed from the top surface and from the side. The platform that is launched (ie the mesa platform 100). This step can be applied to dry etching techniques well known in the art, such as nitrogen (n2), decane (Ch4), argon (helium, chlorine ((8), chlorinated (BC13), carbon fluoride (Cp4)). , single or mixed J, ionic residual, inductive surface-type plasma, or inductive ion engraving, or use hydrochloric acid (HC1), nitric acid (HN03), potassium hydroxide ( Wet etching technique of single or mixed liquid such as K0H), sodium hydroxide (Na0H), sulfuric acid (H2S〇4), phosphoric acid (H3P04), etc., because these etching techniques are well known in the industry, and are not the focus of the present invention. Therefore, the detailed description is not repeated here, and then step 74 is performed. The yellow light lithography technique is also applied to cover the central region 224, the outer ring region and the first electrode region, and then the top surface of the second electrode region is removed downward. The majority of the light correction column 3 in this area is finally step 75, in the position of the first electrode region and the first type of cladding layer 221 corresponding to the second electrode region, two pieces of conductive material are respectively formed with v Xuandi The first type of batch layer 222 is ohmic to the first type of cladding layer 221 Touching the electrode 23, and in a passive atmosphere, 1 〇〇 to 8 〇 (rc treatment 〇. 5~8 〇 minutes, the conductive material of the formed two electrodes 23 is fused, that is, the completion of the device 12 200814366 has Preparation of the light-emitting diode 2 of the sub-micron optical correction column 3. Referring to Figures 9, 10, a second preferred embodiment of the light-emitting diode 2 having the sub-micron optical correction column 3 of the present invention is The light-emitting diode 2 of the first preferred embodiment is similar except that the layer of quantum cells 22 further has a conductive layer 4 formed on the second type of cladding layer 222, which is light-receivable and The fourth current is uniformly dispersed, for example, steel tin oxide (known in the industry), and when the electric energy is applied to the electrode 23, the current is uniformly diffused laterally, thereby increasing the internal quantum efficiency of the quantum unit 22, due to other The structure is similar to that described in the first preferred embodiment, and details are not described herein again. Referring to FIG. 11, the light-emitting diode 2 is prepared by first performing step 81 to a gallium nitride germanium semiconductor material. From a plate-shaped sapphire substrate 21 upwards The crystal forms a first type of cladding layer 221, an active layer, and a first type of cladding layer 222, and causes the first and second type cladding layers 221 and 222 to form a quantum energy barrier with respect to the active layer 223 to generate light by a photoelectric effect. Proceeding to step 82, in 8xl (T3T 〇rr vacuum ambient pressure, sub-in the atmosphere of a predetermined oxygen-containing mixed gas atmosphere, using a highly mature technique such as vapor deposition of a quasi-knife laser coating, bismuth tin oxide Forming a conductive layer 4 on the second type of cladding layer 222 to complete the fabrication of the quantum unit 22. Then proceeding to step 83, defining a first electrode region on the surface of the top surface of the quantum unit 22 (ie, the surface of the conductive layer 4), A central region surrounding the first electrode region, a second electrode region spaced apart from the central region, and an outer ring region surrounding the central region and the second electrode region. 13 200814366

Then, in step 84, the yellow light lithography technique is applied to cover the central region and the first and first electrode regions, and then remove a depth from the top surface of the outer ring region to the upper half of the first type of cladding layer 221. The block domain is such that the structure corresponding to the outer ring region 225 is such that the majority of the light-correcting columns 3' at the same time are corresponding to the central region, and the light can be emitted from the top surface and from the side. The platform (ie, the mesa platform); after that, under the pressure of the vacuum environment, the semi-finished product is placed in a passive atmosphere, and the surface of the transparent conductive layer 4 is modified by a high-temperature diffusion furnace or a rapid heating furnace. After that, step 85 is performed, and the yellow light lithography technique is also applied. After the central region, the outer ring region and the first electrode region of the block are covered, the light correction column 3 corresponding to the region is removed from the top surface of the second electrode region. . Finally, in step 86, two electrodes which are in ohmic contact with the conductive layer* and the first-type cladding layer 221 are respectively formed at positions where the first electrode region and the first-type cladding layer 221 correspond to the second electrode region. 23, and in a pure atmosphere with 100~80 (rc treatment 〇 5~8 〇 minutes, the conductive material of the two electrodes 23 is fused) to complete the light-emitting diode with the sub-micron light-correcting column 3 Preparation of the body 2. As can be seen from the above description, the present invention mainly forms a mesa:1〇〇 while forming a plurality of roots in the non-mesa platform region. The 31st batch 221 bottom 224 top face-up body The light-correcting column 3 which is towering and highly microscopically, by which the refractive index difference between the light-correcting column 3 and its surrounding medium is different, forms a cavity-like cavity and only the effect 'and can be guided From the side of the plane that is just out of the side of the platform, the side that is projected outwards is constantly corrected in the cavity and the way 14 200814366 to change the incident angle and the reflection angle, and finally to be substantially perpendicular to the top surface of the bottom 224. The direction is going forward and forward, not only To increase the light emitting area of the light emitting diode 2, also increases the amount of light traveling forward, and enhanced emission luminance intensity light-emitting diode 2, as indeed hit a purpose of the present invention. The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a conventional light-emitting diode; FIG. 2 is a plan view for explaining the light-emitting diode of FIG. 1; FIG. 3 is a cross-sectional view showing the present invention. A first preferred embodiment of the invention has a light-emitting diode having a sub-micron optical correction column; FIG. 4 is a top view of the light-emitting diode of FIG. 3; FIG. 5 is a SEM photograph showing the light of FIG. Figure 6 is a cross-sectional view showing the majority of the light-correcting column of Figure 5 in combination with the surrounding air medium to correct the travel of the light; Figure 7 is an experimental line diagram illustrating Figure 3 FIG. 8 is a flow chart illustrating the manufacturing process of the light-emitting diode of FIG. 3 . FIG. 9 is a cross-sectional view of the light-emitting diode of the present invention having a sub-micron optical correction column and a general light-emitting diode. FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 10 is a plan view of a light-emitting diode of FIG. 8 for assistance in explaining a light-emitting diode of FIG. 8; FIG. 11 is a flow chart illustrating the second preferred embodiment of the present invention; The LED of Figure 8 has been fabricated

16 200814366

[Main component symbol description] 100 mesa platform 23 electrode 1 light-emitting diode 3 light-correcting column 11 substrate 31 bottom section 12 quantum unit 32 middle section 121 first-type cladding layer 33 top section 122 second-type cladding layer 4 conductive layer 123 Active layer 71 Step 124 Bottom 72 Step 125 Extension 73 Step 13 Conductive layer 74 Step 14 Electrode 75 Step 2 Light-emitting diode 81 Step 21 Substrate 82 Step 22 Quantum unit 83 Step 221 First-type cladding layer 84 Step 222 Second Type batch coating 85 Step 223 Active layer 86 Step 224 Bottom 225 Extension 17

Claims (1)

200814366 X. Patent application scope: 1 · A light-emitting diode having a sub-micron optical correction column, comprising: a plate-shaped substrate; a quantum unit having a layer including a bottom connected to the substrate and a self-contained a first type of the upper portion of the bottom portion of the bottom portion, an active layer formed from the top surface of the extension portion of the first type of cladding layer, and a second type formed from the top surface of the active layer a coating layer, and a plurality of light-correcting columns formed from a top surface of the bottom portion of the first-type cladding layer, the first and second-type cladding layers forming a quantum energy barrier with respect to the active layer to generate light by a photoelectric effect, and the The extension portion of the first type of cladding layer together with the active layer and the second type of cladding layer forms a platform for light to be emitted from the top surface and from the side surface, and the plurality of light correction columns and the surrounding medium are refracted. The difference in coefficient causes the direction of travel of the light emitted laterally from the side of the platform to change, and can travel substantially in the forward direction; and the two electrodes are respectively disposed on the top surface of the bottom portion of the first type of cladding layer and the quantum unit The top surface of the layer structure, but may provide electrical power and respectively the quantum unit and the first and second phase-type ohmic contact layer Pifu. 2. The light-emitting diode having a sub-micron light-correcting column according to the scope of the patent application, wherein the average height of the plurality of light-correcting columns is ΐχΐο_7~2〇xi (r7m, the average diameter is between 〇ΐχΐ〇_7~9χΐ〇·ν, distribution density is between 1~2·5χ1〇3 (# -2. 3. According to the scope of claim 2, the light-emitting diode with sub-micron optical correction column The quantum unit further includes a conductive layer formed of a transparent and electrically conductive material from the top surface of the second type of cladding layer, and the disk 18 200814366 the extension of the first type of cladding layer, the active layer, The two types of coating layers jointly form the light-emitting platform. 4. The light-emitting diode having the sub-micron optical correction enthalpy according to claim 3, wherein each of the light-correcting columns has a section a bottom portion which is identical in structure to the first type of cladding layer and protrudes upwardly from the top surface of the bottom portion of the first type of cladding layer. 5. The luminescence with a sub-micron optical correction column according to item 4 of the patent application scope a diode, wherein each of the light repairs The column further has a middle section which is identical to the structure of the active layer and protrudes upwardly from the top surface of the bottom section. 6. The light-emitting diode having the sub-micron optical correction column according to claim 5 of the patent scope Wherein, each of the light-correcting columns further has a top section which is identical in structure to the second type of cladding layer and protrudes upwardly from the top surface of the middle section. 7· a sub-micron optical correction column The manufacturing method of the light emitting diode comprises: (a) forming a layer of a first type of coating layer and a layer of a second type of coating layer from a plate-shaped substrate with a semi-body material, and one layer is located at the first and second layers. The quantum unit of the active layer between the types of cladding layers and the first and second type of cladding layers form a quantum 旎P with respect to the active layer to generate light by photoelectric effect; (MS means that the top surface of the quantum unit is a first electrode region and a piece a central region surrounding the first electrode region, a first electrode region spaced from the central region, and an outer ring region surrounding the central region and the second electrical region 19 200814366; (C) from the quantum Outside the unit A block depth is removed to the upper half of the first type of cladding layer, so that the structure corresponding to the outer ring area is a plurality of individual light-correcting columns, and at the same time, a structure is reserved for the central area. a light generated by the photoelectric effect from the top surface and from the side of the side; (d) removing the light correction column formed corresponding to the second electrode region; and (e) on the top surface of the quantum unit Corresponding to the position of the first electrode region and the exposed top of the first type of cladding layer facing the second electrode region, respectively forming two electrodes with a conductive material to obtain the light emitting diode with the submicron light correction column 8. The method for manufacturing a light-emitting diode having a sub-micron optical correction column according to claim 7, wherein the step (c) directly forms the block region by etching, and causes the composition The average height of most of the light-correcting columns is between IxlO·7~2〇χ1〇Λη, and the average diameter is between 〇1χ 1〇·7~9xl (T7m, and the distribution density is between ^2 5x^3 ( _2. 9. The method of manufacturing a light-emitting diode having a sub-micron optical correction column according to claim 7, wherein the step (e) is further processed at a temperature of 100 to 800 ° C in a dull atmosphere. For 80 minutes, the conductive materials constituting the two electrodes were fused. 10. The method of manufacturing a light-emitting diode having a sub-micron optical correction column according to claim 7, wherein the step (a) further comprises a transparent and electrically conductive material on the second type of cladding layer. A conductive layer is formed. 20 200814366 The method of claim 10, wherein 'the half is made into 1 to 800 minutes, 11 · The majority of the light-correcting column is made according to the patented range of the light-emitting diode, and the surface crystal is processed at 100 to 800 ° C Granules are modified. There is a sub-micron optical correction column, and the step (c) is formed by placing the product in a passive atmosphere to make the remaining path ^@田廿IV electrical layer of the table 21