TW424338B - Blue light LED with sapphire substrate and the manufacturing method thereof - Google Patents

Abstract

The present invention relates to a blue light LED and the manufacturing method thereof, in particular to a blue light LED using sapphire as the substrate which is to etch at least a channel in the sapphire substrate and forming a gallium nitride thin film layer with approximately the same thickness on the upper and lower layers of the substrate respectively and making the gallium nitride material of the upper and lower layers to contact within the substrate channel; the positive pole and the negative pole are independently formed on the lower bottom of the gallium nitride thin film and on the top epitaxial layer of the light emitting diode on the substrate. Because the channel configuration can provide a channel for the current passing through the substrate between the positive and negative poles, it can become vertical light emitting diode die. Thereby, the present invention not only can greatly reduce the operation area of the dies, but also can simplify the following substrate polishing procedure so as to increase the production yield.

Description

424338 V. Description of the invention (l) The present invention relates to a blue light emitting diode and a manufacturing method thereof, particularly a blue light emitting diode using sapphire as a substrate material, which is mainly provided with at least one in a sapphire substrate. The channel is for the electric current to pass through the pipe, and a gallium nitride thin film layer of similar thickness is formed on the upper and lower layers of the substrate, respectively, to form a vertical blue light-emitting diode with a substantially reduced thickness and active area. Since the development of the light-emitting diode (LED; Light-Emitting Diode) since the 1970s, it has the characteristics and advantages of long life, small size, low heat generation, low power consumption, fast response, and unisex light emission. ， 户 # In the past few decades, light-emitting diodes have been used in a variety of daily life products and instruments, such as computer peripherals, clock displays, advertising signs, traffic lights, communications, or consumer electronics A lot of evidence can be found in the use of light-emitting diodes, and the wide range of applications of this product has to be staggering. Especially when the blue light-emitting diodes are marketed, the red, green, and blue two-color light have been developed and produced successively, so it can be combined into a complete basic structure of full color, which is not only more colorful in color. It is hereby inspiring even if it is used to replace the traditional incandescent light source. Today, in the production of blue light-emitting diodes, it can be divided into two types: sapphire substrate (Sapphire) or silicon carbide substrate (SiC). Large spindle, but due to the physical properties such as brightness and contrast of sapphire substrates or electrical properties such as conductivity

These are all superior to silicon carbide substrates. Of course, their predictability and future development are also relatively higher than silicon carbide substrates D! Please refer to Figure 1, which is the blue light emission used for sapphire substrates.

4243 3 8 V. Description of the invention (2) Cross-sectional view of the structure of the diode; on the sapphire substrate = (-face 12, and then on the gallium nitride thin film layer " 蒸 or steam = Ϊ 4 'can emit blue due to resident The light emitting diode (LED) epitaxial layer of the light source is an insulator on the LED epitaxial layer 'Gem Substrate 10', so you can only choose the top layer of C © " VI / 4 and then individually plate the first in the same plane. The electrode parent and the second electrode (negative electrode ...) become: even the sapphire substrate has its own problems and difficulties. J 丄: The sapphire substrate 10 itself is an insulator material and does not have the same plane. The positive and negative electrodes of the light-emitting diodes 16 and 18 must be coated with a volume that is difficult to shrink. T: The large size makes the light-emitting diodes (U & The sapphire substrate 10 itself is an insulator material, which is in the yield rate; it plays a role in static electricity, and it is relatively easy to cause the GaN thin film layer 12 (thickness H11) on the sapphire substrate 10 during production. The substrate 10 is broken, which is troublesome in the manufacturing process, so its basic The thickness H1 of the board must not be less than 280 micrometers (um). Generally, in mass production, the substrate thickness H1 is approximately higher than 300 micrometers, and HI 1 is about 3 to 4 micrometers, so the thickness ratio of H1 to 酊 1 About ι〇〇_ "'The substrate of such a high thickness will encounter great difficulties in the process of cutting into a die; 4243 3 8 V. Description of the invention (3) (4) It is feasible to facilitate subsequent diamond or lightning cutting After the beans are made, it is necessary to grind the second substrate 100 with a high hardness material such as diamonds about 200 microns or more, which not only causes an increase in cost, but also increases the trouble in the manufacturing process. The reason for this rise is how to address the above problems. Propose a novel solution and not only make the blue light-emitting diode with sapphire as the substrate can be the light-emitting diode, but also greatly reduce the size of the sapphire degree1 In addition to saving costs and expenses, it can also increase its y chemical system. , Has long been the user ’s eager hope and 12 to do = here, and the inventor is based on many years of experience in research, development, and sales of semiconductor elements: practical experience, thinking and improving the winter Personal expertise Knowledge 'has been researched, designed, and thought about in many ways: In order to develop a blue light emitting diode with sapphire as the substrate | = and ,,,, and methods to solve the above problems. It is the main purpose of the invention and its production Provided is a sapphire monitor light-emitting diode and a manufacturing method thereof. The sapphire substrate has two channels on the second and second plates, and the current flow between the two positive and negative electrodes of the upper and lower layers can be turned into a vertical photovoltaic diode crystal. The second purpose of the present invention is to provide a sapphire blue light-emitting diode and a method for manufacturing the same. A sapphire substrate is formed on the same thickness as the substrate. The gallium nitride thin film layer, and the stresses that can be formed in the annealed layer can offset each other, so the required substrate thickness can be 150 μm or even less than 100 μm, which not only prevents Sapphire ^ Reduced to stone substrate

Page 6 424338: V. Description of the invention (4) --- One ^ one ^ Can rupture, but also saves the use of substrate material resources and relatively simplifies the process steps of polishing the substrate afterwards. Yet another object of the present invention is to provide a blue light-emitting diode with sapphire as a substrate and a method for manufacturing the same. Product Yield. | In order to make your reviewing committee understand the structural features of the present invention and what they have achieved | Gongzheng has a better understanding and understanding, I would like to refer to the preferred embodiment diagram and | with detailed explanations' description is as follows: 丨 First, please Refer to FIG. 2, which is a schematic structural diagram of a preferred embodiment when making a sapphire substrate according to the present invention. As mentioned above, a gallium nitride film conventionally formed on a sapphire substrate will form a small stress when annealing and cooling. And acting on the sapphire substrate, it is easy to cause the substrate to be broken. Therefore, it is customary to increase the thickness of the sapphire substrate to improve its stress resistance and prevent the sapphire substrate from being broken. In the present invention, when preparing the sapphire substrate 20, gasification film layers 222 and 224 having thicknesses (H3, H4) and similar or identical operating areas can be formed on the upper and lower sides of the sapphire substrate 20 respectively, so they can be cooled by annealing. At this time, although the stress on the sapphire substrate 20 is still not small, but because the stresses on the upper and lower sides will offset each other, it will not cause damage to the sapphire, so the thickness (H2) of the sapphire substrate 20 is also There is no need to use such a high level. According to the experimental results, the thickness can be less than 150 micrometers (ujn), and even less than 100 micrometers. Therefore, it can be obtained not only in terms of the amount of material used or the process of polishing the substrate afterwards. Great effect.丨

Page 7 4243 3b 5. Description of the invention (5) Furthermore, the main manufacturing steps of the photodiode Step 1: (Sapphire) Set at least one step 3 A shown in Figure 2: Method (MOVPE) and make the nitride In step 3, a part of the empty film 3 made of a conductive material 3 2 2 is made of electrical material, so the figure C is shown; Step 4: The formula to form a 4, of course; and I .; Step 5 :! Figures 3A through 3E of the first phase of the ore bed are sectional views of the structure of the blue light emission process of the present invention; as shown in the figure, the steps include: + ί a < 30 micron-sized sapphire substrates ^ f uses chemical etching or mask engraving to open a channel 3 that runs through the substrate 30 and has a slope, such as the top layer of the plate 30, with an organic metal vapor phase epitaxial day A gallium nitride thin film layer 322 is formed in the following formula. Part of the material of the gallium thin film 3 2 2 is stored as shown in FIG. 3B;: Π: ί 板 3 〇 The bottom layer uses epitaxial or sputtering methods, layer 32 6, the conductive Layer 3 26 can be made of non-metal conductive μ & and 7 忒 conductive layer 3 2 6 material also exists in the channel 3, and is the same as previously existing in channel 3 The gallium nitrides in τ are connected to each other. Since the gallium nitride film 3 2 2 itself is conductive, the connection will form a complete conductive path, such as the third in the gallium nitride film drawer. The top layer has a P-η interface and can emit a blue light source by sputtering or evaporation.]) The epitaxial layer 3 can be an np interface, as shown by the scratch mark, as shown in Figure 3d, respectively, in the LED epitaxial. Layer 34 top layer and conductive layer 3 2 6 bottom pair of the first electrode 36 and the second electrode; " " 424338 V. Description of the invention (6) " ^--forming a vertical light-emitting diode grain material , As shown in Figure 3 5; Since the LED epitaxial layer 34, the gallium nitride thin film layer 3 2 2 and the conductive layer 3 2 6 are all conductive materials, the two electrodes 3 6 and 38 can pass through the above-mentioned element and the passage 31 reference. A complete electrical channel is provided, as shown by the dotted line. Therefore, this upright blue light-emitting diode crystal can be completed after the post-segmentation. Because the positive and negative electrodes 3 6, 3 8 are located on different planes, the LED epitaxial layer 3 4 is reduced in size. ; With area, not only can save material use, but also meet the goal of short and thin products.丨 Finally, please refer to FIG. 4, which is a structure of another embodiment of the present invention! As shown in the figure, in this embodiment, the technology disclosed in FIG. 2 is combined with the conductive layer 3 2 6 The non-metallic conductive material is optional! The same material as the GaN thin film layer 3 2 2 and the thick production of the upper and lower layers | Bu H3, H4) are approximate 'even relative', which can not only offset GaN: | The stress generated by the film layers 3 2 2 and 3 24 during annealing and cooling to maintain the blue: sapphire substrate 30 is not damaged, and the thickness of the sapphire substrate 30 can be greatly reduced, even in material management It is also more convenient.

丨 In addition, the sloped channel 3 i 'mentioned in step 1 above is mainly used to form the thin gallium nitride layer 322 and the conductive layer 326 in steps 2 and 3 to ensure that it is in the channel. The contact j within 3 丄 is considered, but if it is convenient for the process, in fact, a straight channel can also be opened. 31, the same applies to the present invention. The current can flow between the two electrodes on the front and back sides (as shown by the dotted line) By). Of course, the first electrode 3 6 located on the LED epitaxial layer 3 4 can also use transparent materials for consideration of light emission.

4243 3 8 V. Description of the Invention (7)-One is made to form a transparent electrode. In addition, since the conductive layer 3 2 6 or the gallium nitride thin film layer 3 2 4 itself is made of a conductive material, the second electrode 3 8 may also be replaced by the conductive layer 3 2 6 or the gallium nitride thin film layer 3 2 4 Not established. In summary, the present invention relates to a blue light emitting diode and a manufacturing method thereof, particularly a blue light emitting diode using sapphire as a substrate material, which is mainly provided with at least one channel in a sapphire substrate for power supply. | Flow through the pipeline, and two thin layers of gallium vaporized with the same thickness are formed on the two layers above and below the substrate, respectively. It is a vertical light-emitting diode with a thickness and active area that can be greatly reduced. Therefore, the present invention is really a novel, progressive, and industrially usable person, and should meet the patents stipulated by the Chinese Patent Law. The application requirements are undoubtedly, the invention patent application is submitted in accordance with the law. , I feel the prayer. However, the above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. For example, an impurity layer may be added between the LED epitaxial layer and the gallium nitride thin film layer, such as Indium aluminum gallium phosphide layer, or adding other WSiC, ain, SiO2, InGaN, Sn02, AlInGaP layers, etc. on top of other thin film layers, for example, according to the shape, structure, characteristics and spirit described in the scope of the patent application of the present invention Equal changes and modifications shall be included in the scope of patent application of this | invention. (—) Brief description of the diagram: Figure 1: is a sectional view of the structure of a blue light-emitting diode used to use sapphire as a substrate. 丨 view;

Page 10 4 2.4 3 3 8 Create a diagram:

V. Description of the invention (8) Figures 3A to 3E: Sectional view of the step construction of the blue light emitting diode of the present invention > (2) Brief description of drawing number: 1 0 sapphire substrate 1 2 GaN thin film layer 1 4 LED crystal layer 1 6 first electrode 1 8 second electrode 2 0 sapphire substrate 2 2 2 GaN thin film layer 2 2 4 GaN thin film layer 3 0 Sapphire substrate 3 1 Channel 3 2 2 GaN thin film layer 3 2 4 GaN thin film layer 3 2 6 Conductive layer 3 4 LED crystal layer 3 6 First electrode 3 8 Second electrode

Claims (1)

42 ^ 3 ^ 8 VI. The scope of the patent application The channel is a straight line 8 • The blue light-emitting diode described in the first item of the patent application scope, wherein the thickness of the sapphire substrate is greater than 0 micrometers but not greater than 150 Micrometer (um). 9. The blue light-emitting diode according to item 1 of the scope of patent application, wherein the first electrode system can be a transparent electrode. 1 〇. The blue light-emitting diode described in item 1 of the patent scope of the application, is still 玎, the second electrode formed on the bottom layer of the side conductive layer, thereby being able to pass through the channel of the blue negative substrate and the first electrode The person forming the current path • A sapphire-based substrate includes at least the following steps: A method for manufacturing a blue light-emitting diode A channel on a sapphire substrate; at least one of the two sides of the substrate is provided (2) (3) the gallium nitride thin film material on the sapphire substrate exists on the sapphire substrate substrate in the channel < the top layer of the gallium nitride thin film material forms a nitrogen The chemical substance exists in the layer of the channel to form a conductive part of the space and is in contact with it; the thin layer of gallium, which makes part of the space; and the conductive material exists in the channel (4) in the gallium nitride film layer Stupid crystal layer; and the page layer forms an LED with a pn interface (5) Bonding on the top layer of the LED crystal layer. As the scope of the patent application, the first electrode is the channel opened in step (1). The manufacturing method described in the item, wherein the system has a slope. 42 43 3 8 • Application scope 1 3 * The manufacturing method described in item 11 of the scope of patent application, wherein in step (2), a gallium nitride thin film layer is formed on the organic metal vapor phase epitaxy method. On top of sapphire substrate. 1 4 · The manufacturing method as described in item 11 of the scope of patent application, wherein the conductive layer formed in step (3) is made of a non-metallic conductive material. 1 5 * The manufacturing method described in item 11 of the scope of patent application, wherein the thickness of the gallium nitride layer formed in step (2) and the thickness of the conductive layer formed in step (3) are similar. 16. The manufacturing method described in item 11 of the scope of patent application, wherein the conductive layer formed in step (3) is optionally made of gallium nitride. The manufacturing method described above, wherein the gallium nitride layers formed in step (2) and step (3) have the same thickness. 18 · The manufacturing method as described in item 11 of the scope of patent application, wherein the thickness of the sapphire substrate selected in step (1) is greater than 0 micrometers but not greater than 150 micrometers (um). 1 9 · The manufacturing method as described in item 11 of the scope of patent application, wherein the first electrode system formed in step (5) may be a transparent material maker 0 2 0 · As the item 11 of scope of patent application The manufacturing method may further include a step (6): forming a second electrode corresponding to the first electrode on the bottom layer of the conductive layer. Page 14