TWI241727B - Light emitting diode structure and manufacturing method of the same - Google Patents

Abstract

A light emitting diode (LED) structure comprises an substrate, a N-type epitaxy layer formed on the substrate, a light emitting layer formed on the N-type epitaxy layer, a P-type epitaxy layer formed on the light emitting layer, a nano-meter conductive layer formed on the P-type epitaxy layer, a transparent conductive layer formed on the nano-meter conductive layer, a first electrode formed on the transparent conductive layer to be a P-type bonding pad, and a second electrode formed on the N-type epitaxy layer to be a N-type bonding pad.

Description

1241727 V. Description of the invention α) Technical field to which the invention belongs: The present invention relates to a light-emitting diode (LED), and in particular to a method for forming a nano-conductive layer between a transparent conductive layer and a P-type epitaxial layer ( Nano-conductive layer) and its manufacturing method. Prior technology: The shortage of energy in the world is an indisputable fact. All countries in the world are actively investing in the development of energy-saving products. The advent of energy-saving light bulbs is the product of this trend. However, with the advancement of light-emitting diode (LED) technology, the application of white light-emitting diodes has also gradually developed, including: indicator lights, portable flashlights, LCD backlight panels, ground lights / escape lights / medical equipment light sources, automobiles Meters and built-in lights, auxiliary lighting, main lighting ... etc. In short, it is the current main application of backlight and lighting. So the next generation of lighting market will be the world of light-emitting diodes. Because the light-emitting diode has the advantages of lightness, power saving and long life, it conforms to the trend of the world. The United States, Japan and other countries have invested in development with their national strength, and China's light-emitting diode industry also plays a pivotal role in the world market. Therefore, in the next generation of development in this field, Taiwan Will also play an important role.

1241727 V. Description of the invention (2) At present, the application of light-emitting diodes in the white light market has brought the small-scale lighting market to another realm. The backlight of mobile phones has been replaced by light-emitting diodes. From the early yellow and green light-emitting diodes to the current white or blue-white light-emitting diodes', mobile phones have been decorated with colorful colors. As for the backlight sources of personal digital assistants (PDAs) and liquid crystal display panels (TFT-LCDs) in the future, they will also become the world of light-emitting diodes. Its thin, thin, and power-saving advantages will give it a non-replacement status.

As far as the current stage is concerned, there is still a long way to go before the era of white light-emitting diode lighting. If white light-emitting diodes are to replace the current lighting field, the luminous efficiency must be at least 100 lm / w or more. This goal will also become the goal of the efforts of all countries. Therefore, based on the above-mentioned needs, and in response to the needs of the trend, the present invention will propose a light-emitting diode structure and a method for manufacturing the same. The bean can improve the light-emitting efficiency of the light-emitting diode and reduce the operating voltage of the light-emitting diode. SUMMARY OF THE INVENTION The object of the present invention is to provide a light emitting diode structure and a manufacturing method thereof.

Page 7 1241727 V. Description of the invention (3) Light-emitting diode with contact resistance between P-type epitaxial layer. Another object of the present invention is to provide a light emitting diode which can reduce the operating voltage of the light emitting diode. Another object of the present invention is to provide a light emitting diode capable of improving light emitting efficiency. A light emitting diode structure includes: a substrate; an N-type epitaxial layer formed on the substrate; a light-emitting layer formed on the N-type epitaxial layer; a P-type stupid crystal layer formed on On the light-emitting layer; a nano-conductive layer formed on the P-type epitaxial layer; a transparent conductive layer formed on the nano-conductive layer; a first electrode formed on the transparent conductive layer for use As a P-type contact; and, a second electrode is formed on the N-type epitaxial layer to serve as an N-type contact. A method for manufacturing a light emitting diode includes: first, a substrate is provided, and then an N-type stupid crystal layer is formed on the substrate, and then a light-emitting layer is formed on the N-type epitaxial layer; A P-type epitaxial layer is formed on the light-emitting layer; then, a nano-conductive layer is formed on the P-type epitaxial layer; then, a transparent conductive layer is formed on the nano-conductive layer; after that, a first The electrode is used as a P-type contact on the transparent conductive layer; finally, a second electrode is formed on the N-type epitaxial layer as an N-type contact.

Page 8 1241727 V. Description of the invention (4) The method for manufacturing the light-emitting diode further includes a step of forming a buffer layer on the substrate. Implementation method: The present invention discloses a structure of a light emitting diode and a manufacturing method thereof. Please refer to FIG. 1, which is a cross-sectional view of a light emitting diode structure according to the present invention. The above light emitting diode structure includes: a substrate 100; and an N-type stupid crystal layer 102, which is formed on a buffer layer 101. For one embodiment, the material of the buffer layer 101 may be gallium nitride (GaN), aluminum nitride (A1N), or vaporized dope (GaAIN). In addition, a light emitting layer 103 is formed on the N-type worm crystal layer 102. The light-emitting layer 103 is an active layer, which may be formed by alternately stacking a plurality of well layers and a plurality of barrier layers (barr ier 1 ay er). A P-type stupid crystal layer 104 is formed on the light-emitting layer 103. The material of the P-type epitaxial layer 104 can be selected from gallium nitride (GaN), indium gallium nitride (InGaN), or one of the gallium nitride-based nano-conductive layers 105, and is formed on the P-type epitaxial layer. Level 1 0 4. For one embodiment, the thickness of the nanometer conductive layer 105 is 5 to 100 Angstroms (A), and the nanometer conductive layer 105 may be an N-type nanometer conductive layer or a P-type nanometer. Conductive layer or N-type / P-type nano-conductive layer combination. Nanometer conductive layer

1241727 V. Description of the invention (5) 1 0 5 can be formed by a method of planar doping (6 doping) using a metal organic chemical vapor deposition (MOCVD). The purpose of the nanometer conductive layer is to do plane doping (( The 5 nanometer conductive layer has a high impurity carrier (> 1 0 2 0 cm-l), which has a higher conductivity than ordinary semiconductors. It can effectively reduce the interface between the transparent conductive layer and P-type epitaxy. The contact resistance reduces the operating voltage. In addition, a transparent conductive layer 106 is formed on the nano-conductive layer 105. The material of the transparent conductive layer 106 can be selected from (1, 0), (120), (human) 20), (CTO), (TiWN), or (Ni / Au). A first electrode 107 is formed on the transparent conductive layer 106 and is used as a P-type contact. In addition, A second electrode 108 is formed on the N-type stupid crystal layer 102, and is used as an N-type contact. The second electrode 108 is an N-type electrode, and its material can be selected from titanium / One of aluminum (T i A 1), titanium / aluminum / titanium / gold (Ti / Al / Ti / Au) and titanium / aluminum / nickel / gold (Ti / Al / Ni / Au) alloy. Polar body The manufacturing method includes the following steps. First, a substrate 100 is provided. Next, a buffer layer 101 is formed on the substrate 100. For example, the buffer layer 101 is described above. The material can be gallium nitride (GaN), aluminum nitride (A 1 N), or aluminum gallium nitride (GaA 1 N). Then, an N-type epitaxial layer 10 is formed on the buffer layer 101. The material of the P-type epitaxial layer 104 may be selected from one of gallium nitride (G a N), indium gallium nitride (I nGaN), or gallium nitride.

Page 10 1241727 5. Description of the invention (6), a light-emitting layer 103 is formed on the above N-type stupid crystal layer 102. The light-emitting layer 103 is an active layer, which may be formed by stacking a plurality of well layers and a plurality of barrier layers (barrier 1 a y e r) alternately. Next, a P-type stupid crystal layer 104 is formed on the light-emitting layer 103. Then, a nano conductive layer 105 is formed on the P-type epitaxial layer 104. For example, the thickness of the nano-conductive layer 105 is 5 to 100 Angstroms (A), and the nano-conductive layer 105 may be an N-type nano-conductive layer or a P-type nano-conductive layer. Or N-type / P-type nanometer conductive layer combination. The nano conductive layer 105 can be formed by a planar organic impurity (5 impurity) method using a metal organic chemical vapor deposition (MOCVD) method. After that, a transparent conductive layer 106 is formed on the nano-conductive layer 105. The material of the transparent conductive layer 106 can be selected from one of 0, 120, 20, Z η 0, T i W N, or Ni / A u. A platform is formed on the N-shaped stupid crystal layer. Next, a first electrode 107 is formed on the transparent conductive layer 106, which is used as a P-type contact. Finally, a second electrode 108 is formed on the N-type epitaxial layer platform region 102, which is used as an N-type contact. The second electrode 108 is an N-type electrode, and its material can be selected from titanium / aluminum (Ti i 1), titanium / aluminum / titanium / gold (Ti / Al / Ti / Au), and titanium / aluminum / record / One of gold (Ti / Al / Ni / Au) alloys ~ ° The main advantages of the present invention are as follows: 1. The manufacturing process of the light emitting diode of the present invention is simple.

1241727 V. Description of the invention (7) 2. The light emitting diode of the present invention can reduce the contact resistance between the transparent conductive layer and the P-type epitaxial layer. 3. The light emitting diode of the present invention can reduce the operating voltage of the light emitting diode. 4. The light emitting diode of the present invention can improve the light emitting efficiency of the light emitting diode.

The present invention has been described above with reference to the preferred embodiments, but it is not intended to limit the scope of patent rights claimed by the present invention. The scope of patent protection depends on the scope of patent application and its equivalent fields. Anyone skilled in this field can make changes or modifications without departing from the spirit or scope of this patent, which are all equivalent changes or designs made in the spirit disclosed by the present invention, and should be included in the scope of patent application described below. Inside.

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Claims (1)

1241727 6. Scope of patent application Patent scope: 1. A light-emitting diode structure including: a substrate; a first-type stupid crystal layer formed on the substrate; and a light-emitting layer formed on the first-type semiconductor. A crystal layer; a second-type epitaxial layer formed on the light-emitting layer; a nano-conductive layer formed on the second-type epitaxial layer; a transparent conductive layer formed on the nano-conductive layer; A first electrode is formed on the transparent conductive layer to serve as a second-type contact; and a second electrode is formed on the platform region of the first-type epitaxial layer to serve as a first-type contact. 2. If the structure of the light emitting diode of item 1 of the patent application scope further includes a buffer layer formed on the substrate. 3. The structure of the light emitting diode according to item 2 of the patent application scope, wherein the material of the buffer layer is gallium nitride (GaN), aluminum nitride (A1N) or aluminum gallium nitride (GaAIN). The structure of the light-emitting diode of the first scope of the patent application, wherein the thickness of the nano-conductive layer is 5 to 100 angstroms (A). 1241727 6. Application for patent scope 5. For the structure of the light-emitting diode in item 4 of the patent application scope, wherein the nanometer conductive layer is a first type nanometer conductive layer, a second type nanometer conductive layer, or a first type / A second type of nano-conductive layer combination. 6. The structure of the light-emitting diode according to item 4 of the application, wherein the nano-conductive layer is formed by a metal organic chemical vapor deposition (MOCVD) planar doping (5 doping) method. 7. For the structure of the light-emitting diode of item 1 of the patent application, wherein the material of the second type epitaxial layer may be selected from gallium nitride (GaN), indium gallium nitride (I nGaN), or gallium nitride system one. 8. For the structure of the light-emitting diode in item 1 of the scope of patent application, the material of the transparent conductive layer may be selected from ITO (indium tin oxide), IZO (indium zinc oxide), AZO (zinc aluminum oxide), TiWN ( Titanium tungsten nitride), ZnO (zinc oxide) or Ni / Au (nickel / gold) or a combination thereof. 9. For the structure of the light-emitting diode of item 1 of the patent application, wherein the first electrode is a second type electrode, the material can be selected from titanium / aluminum (T i / A 1), titanium / gold (Ti / Au), titanium / aluminum / titanium / gold (Ti / Al / Ti / Au) and titanium / aluminum / nickel / gold (Ti / Al / Ni / Au) alloys. 10. The structure of the light emitting diode according to item 1 of the scope of patent application, wherein the second electrode is a first type electrode, and the material can be selected from titanium / aluminum (T i A 1), 1241727 6. Scope of patent application One of the alloys of Ti / Al / Ti / Au and Ti / Al / Ni / Au. 1 1. The structure of the light-emitting diode according to item 1 of the scope of patent application, wherein the first type described above is an N-type and the second type is a P-type. 1 2. A method for manufacturing a light emitting diode, comprising: providing a substrate; forming a first-type stupid crystal layer on the substrate, and forming a first electrode on a platform region of the first-type epitaxial layer; Used as a first type contact; and forming a light emitting layer on the first type epitaxial layer; forming a second type epitaxial layer on the light emitting layer; forming a nanometer conductive layer on the second type Forming an epitaxial layer; forming a transparent conductive layer on the nano conductive layer; and forming a second electrode on the transparent conductive layer for use as a second type contact. 13. The method for manufacturing a light-emitting diode according to item 12 of the scope of patent application, further comprising the step of forming a buffer layer on the substrate. 14. The method for manufacturing a light-emitting diode according to item 12 of the scope of patent application, wherein the material of the buffer layer is gallium nitride (GaN), aluminum nitride (A1N), or aluminum gallium nitride (GaA 1N). Page 16 1241727 VI. Application scope of patent 15. The manufacturing method of the light-emitting diode according to item 12 of the scope of patent application, wherein the thickness of the nano-conductive layer is 5 to 100 angstroms (A). 16. The method for manufacturing a light-emitting diode according to item 12 of the application, wherein the nano-conductive layer is a first-type nano-conductive layer, a second-type nano-conductive layer, or a first-type / second-type. Nano conductive layer combination. 17. The method for manufacturing a light emitting diode according to item 12 of the scope of patent application, wherein the nanometer conductive layer is a method of planar doping ((5 doping) using a metal organic chemical vapor deposition (MOCVD) method. 18. The manufacturing method of the light-emitting diode according to item 13 of the patent application scope, wherein the material of the second-type epitaxial layer can be selected from gallium nitride (GaN), indium gallium nitride (I n G a N) or one of the nitrided nitride systems. 19. The method for manufacturing a light emitting diode according to item 12 of the patent application scope, wherein the material of the transparent conductive layer can be selected from ITO (indium tin oxide), IZO ( Indium oxide), AZO (zinc aluminum oxide), TiWN (titanium tungsten nitride), ZnO (zinc oxide), or Ni / Au (nickel / gold) or a combination thereof. 2 0. Such as the scope of patent application 1 2 The method for manufacturing a light-emitting diode according to the item, wherein the first electrode is a second-type electrode, and the material is titanium / aluminum (T i / A 1), titanium / gold (1 ^ 7 ^ 10, titanium / aluminum / Titanium / gold (1 ^ / eight 1/11 丨 / ^ 11) and titanium / aluminum / record / gold Page 17 1241727 VI. One of the patent applications (Ti / Al / Ni / Au) alloys. 2 1. The method for manufacturing a light emitting diode according to item 12 of the scope of patent application, wherein the first electrode is formed by a sputtering vapor deposition method. 2 2. The method for manufacturing a light emitting diode according to item 12 of the patent application scope, wherein the second electrode is a first type electrode, and the material can be selected from titanium / aluminum (TiAl), titanium / aluminum / titanium / gold (Ti / Al / Ti / Au) and titanium / aluminum / nickel / gold (Ti / Al / Ni / Au) alloys. 2 3. The method for manufacturing a light emitting diode according to item 12 of the scope of patent application, wherein the first type described above is an N type and the second type is a P type.