A LED flip chip and a manufacturing method thereof

Abstract

The invention relates to the technical field of semiconductors and in particular provides an LED flip chip and a manufacturing method thereof. The method comprises the steps of: A) providing a substrate on which an N-type gallium nitride layer, multiple quantum well layers and a P-type gallium nitride layer are sequentially formed; B, forming an ohmic contact layer on the surface of the substrate;C, forming a mirror dielectric layer on the ohmic contact layer; D, forming a mirror metal layer; E, etching the exposed P-type gallium nitride layer and the quantum well layers to form an N-electrode contact hole; F, forming an isolation layer; G, forming an N electrode in thr N electrode contact hole and forming a P electrode on a mirror metal layer covering the exposed ohmic contact layer; H,thinning the back surface of the sapphire substrate and forming a coarse alumina lay on the back surface of the sapphire substrate. The manufacturing method of the invention can improve the light emitting efficiency of the LED flip chip, thereby improving the photoelectric conversion efficiency of the LED flip chip, avoiding the influence on the front side of the chip and reducing the manufacturing cost.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to an LED flip 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 of cu...

AI Technical Summary

Problems solved by technology

[0005] The light emitting layer added between the PN junction and the P electrode of the flip-chip LED chip is a metal structure, which relies on the high reflectivity of Ag, Al, Rh and other metals to complete the reflection of the light emitted by the quantum well layer to the bottom of the chip. There are many metal reflections. Disadvantages: There are different degrees of light absorption for each light incident angle, and there is a limit to the reflectivity, for example, the reflectivity of the mirror is lower than 90%

Therefore, it still restricts the quality of flip-chip LED chips