Flip LED chip and manufacturing method thereof

Abstract

The invention discloses a flip LED chip and a manufacturing method thereof. A front-end structure containing a sapphire substrate, an N type gallium nitride layer, a quantum well layer, and a P type gallium nitride layer is provided, wherein the N type gallium nitride layer, the quantum well layer, and the P type gallium nitride layer are formed on the front side of the sapphire substrate; an ohmic contact layer and a reflecting layer are formed on the front-end structure; a first electrode connecting the N type gallium nitride layer and a second electrode connecting the reflecting layer are formed; and reduction processing is carried out on the back side of the sapphire substrate and a rough aluminium oxide layer is formed. Compared with the prior art, because of the aluminium oxide layer with the rough surface and the material consistent with the substrate material, an effect of improvement of the luminous efficiency based on surface roughening is realized; and defects of great influence on the front side and high cost in the prior art can be overcome. Therefore, the preparation cost is low; the process complexity is low; and the large-scale mass production can be realized easily.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a flip-chip LED chip and a manufacturing method thereof. Background technique [0002] For traditional front-mounted LED chips, P-type GaN is difficult to dope, resulting in low hole carrier concentration and difficulty in growing thick, resulting in difficult diffusion of current. At present, the method of preparing ultra-thin metal film or ITO film on the surface of P-type GaN is generally used to achieve The current has to spread evenly. However, the metal thin film electrode layer has to absorb part of the light to reduce the light extraction efficiency, and if the thickness is reduced, it will in turn limit the current diffusion layer to achieve uniform and reliable current diffusion on the surface of the P-type GaN layer. Although the light transmittance of ITO is as high as 90%, the electrical conductivity is not as good as that of metal, and the diffusion effect o...

AI Technical Summary

Problems solved by technology

Difficulties mainly include the need to protect the front structure of the chip, the need to prepare additional masks, and strict control of process conditions. Therefore, the degree of difficulty is relatively high

In addition, the flip-chip LED chip prepared by thinning the sapphire substrate does not roughen the light-emitting surface.

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