Light-emitting diode and method of making the same

Abstract

The invention discloses a light emitting diode (LED) and a manufacturing method thereof. The LED comprises a substrate, a buffer layer, an unintentional doping layer, a first doping layer, a first heavy doping layer, a first ohmic contact layer, a first high doping layer, a first isolation layer, a second doping layer, a first current blocking layer, an active region, a second current blocking layer, a third doping layer, a second ohmic contact layer, a transparent conductive layer, a first electrode, a second electrode and a third electrode, wherein the second doping layer comprises a first platform, the first high doping layer comprises a second platform, the first ohmic contact layer comprises a third platform, the first platform, the second platform and the third platform are differentin surface roughness, the first electrode directly contacts with the first platform, the second platform and the third platform, and the first electrode and the second electrode realize electrical isolation through a second protection layer. The LED is advantaged in that the manufacturing process is simple, manufacturing cost of chips is reduced, and a current congestion problem of the LED is effectively solved.

Description

technical field [0001] The present invention relates to light-emitting diodes, and more specifically, to a light-emitting diode and a manufacturing method thereof. Background technique [0002] A light emitting diode (Light Emitting Diode, LED) is an optoelectronic semiconductor element that can convert current into a specific wavelength range. It has the advantages of low power consumption, small size, high brightness, easy matching with integrated circuits, and high reliability, and is widely used as a light source. [0003] Current blue-green light-emitting diodes have the problem of current crowding, especially for high-power light-emitting diodes, which causes a significant drop in saturation current to a large extent, thereby reducing light efficiency. The inventors found that the reason for the current crowding is that the structure of blue-green light-emitting diodes is mostly epitaxial multi-layer gallium nitride-based material structure on a sapphire substrate, an...

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Problems solved by technology

[0003] The current blue-green light-emitting diodes have the problem of current crowding, especially for high-power light-emitting diodes.

The inventors found that the reason for the current crowding is that the structure of blue-green light-emitting diodes is mostly epitaxial multi-layer gallium nitride-based material structure on a sapphire substrate, and the sapphire substrate is a non-conductive material, so the light-emitting diode formed The two electrodes are distributed horizontally, and the horizontally distributed electrodes are at the same level, which leads to current crowding, especially for high-power flip-chip LEDs. Due to the large driving current, current crowding is more likely to occur, resulting in a significant drop in saturation current. , resulting in a significant reduction in luminous efficacy

[0004] In the prior art, in order to improve the current crowding phenomenon, one solution is to design a complex electrode structure that cooperates with each other. Multiple isolation layers are used between the two electrodes to isolate the unnecessary contact between the electrode and the epitaxial material, but the complex electrode structure, It leads to complex manufacturing process, and also sacrifices the area of ​​the active area

Another solution is to adopt a vertical chip structure, but the substrate lift-off process and silicon substrate bonding process are required in the production process

Both of the above two solutions lead to an increase in the production cost of the chip and a decrease in the chip yield.

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