A kind of preparation method of nitride light-emitting diode

Abstract

A method for manufacturing a nitride light emitting diode. A PVD method is used to deposit an AlN film layer (2) on a patterned substrate (1) having a larger depth; a CVD method is used to deposit a nitride epitaxial layer (3) having a small thickness on the AlN film layer; and a doped active layer (4) and a p-type layer (5) are formed on the nitride epitaxial layer. The thickness of an epitaxial layer is decreased to reduce stress so as to improve warping of an epitaxial wafer, and then improve electrical property uniformity of a single epitaxial wafer; a patterned substrate having a large depth is used to improve light extraction efficiency; and a high-concentration impurity is doped in an active layer, so that voltage characteristics can be effectively reduced without affecting current leakage, so as to improve overall yield of the light emitting diode.

Description

technical field [0001] The invention relates to a method for preparing a light-emitting diode, which belongs to the technical field of light-emitting diode manufacture. Background technique [0002] Physical vapor deposition (Physical Vapor Deposition, PVD) technology refers to the use of physical methods under vacuum conditions to vaporize the material source—solid or liquid surface into gaseous atoms, molecules or parts of ionization into ions, and through low-pressure gas (or plasma) Body) process, the technology of depositing a thin film with a certain special function on the surface of the substrate. Physical vapor deposition methods mainly include: vacuum evaporation, sputtering coating, arc plasma plating, ion coating, and molecular beam epitaxy, etc.; it can not only deposit metal films, alloy films, but also deposit compounds, ceramics, semiconductors, polymers, etc. Membranes, etc.; this technology has a simple process, less environmental pollution, less consumpti...

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Problems solved by technology

[0004] However, when the conventional metal-organic chemical vapor deposition method (MOCVD method) is used to epitaxially grow LED materials on the surface of the patterned substrate, the depth of the pattern on the surface of the patterned substrate is required to be less than 2 microns. When the depth value is greater than this value, The MOCVD method cannot obtain a good-quality epitaxial film layer; in addition, due to the uneven surface characteristics of the patterned substrate, it is necessary to laminate a thicker buffer layer between the n-type layer and the substrate in the LED structure to make the n-type layer grow. The surface of the previous epitaxial layer reaches the required smooth structure, which is beneficial to the lamination of the subsequent epitaxial layer. However, the thicker underlying structure produces greater stress, which causes the warped LED structure to be larger, which is not conducive to the implementation of subsequent processes (such as subsequent cracks in the manufacturing process), and cause significant differences in the electrical properties of each part of the monolithic LED structure, affecting the growth yield; and due to the quality of the bottom layer, the doping concentration of the active layer is also limited by it, and a higher doping level cannot be obtained , thus limiting the further improvement of the voltage equielectricity

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