A kind of LED chip electrode and manufacturing method thereof

Abstract

The invention discloses a fabrication method of an LED chip electrode. The fabrication method includes the following steps that: dry etching is performed on an epitaxial layer, an N type GaN layer is exposed; an indium tin oxide film conductive layer is fabricated; a chromium layer is formed through evaporation; a nickel layer is formed through evaporation; annealing treatment is performed on the nickel layer under a nitrogen atmosphere, so that the nickel layer can form uniformly-distributed spherical nickel particles on the surface of the chromium layer; with the spherical nickel particles adopted as an etching mask, the chromium layer is etched, so that nanoscale recessed rectangular pits can be formed on the surface of the chromium layer through etching; the spherical nickel particles are removed through corrosion; an aluminized layer, a titanium layer, a platinum layer and a gold layer are formed sequentially through evaporation; and glue is removed through peeling, and as a result, the LED chip electrode can be obtained. The invention also discloses an LED chip electrode; the LED chip electrode includes a chromium layer, an aluminum layer, an evaporation aluminum, a titanium layer, a platinum layer and a gold layer which are distributed sequentially from bottom to top; and nanoscale recessed rectangular pits can be formed on the surface of the chromium layer through etching. According to the LED chip electrode and the fabrication method thereof of the invention, the nanoscale lumpy structures can be formed on the surface of the chromium layer, so that the exitance of light on the surface of the chromium layer can be increased; light that is reflected into the chip by the aluminum layer and is further reflected out can be increased, and therefore, the luminous efficiency of an LED can be obviously improved.

Description

technical field [0001] The invention relates to the field of optoelectronic devices, in particular to an LED chip electrode and a manufacturing method thereof. Background technique [0002] LED is a solid light source, which is a light-emitting device made of semiconductor P-N junction. During forward conduction, the minority carriers in the semiconductor recombine with the majority carriers, and the released energy is emitted in the form of photons or partly in the form of photons. Semiconductor LED lighting has significant advantages such as high efficiency, energy saving, environmental protection, long service life, etc., and has been widely used in various fields such as street lamps, display screens, indoor lighting, and automobile lights. How to improve luminous efficiency is the main problem that LED needs to solve. [0003] At present, most LED electrodes use a reflective electrode structure containing an aluminum layer. The aluminum layer in the electrode can refl...

AI Technical Summary

Problems solved by technology

The Al layer is directly in contact with the surface of the GaN epitaxial layer. Although the luminous efficiency of the LED can be guaranteed, there are two problems: one is that the adhesion between the entire electrode and GaN will be poor, and the electrode will be damaged during the subsequent wire bonding and bonding process. Easy to fall off; Second, the voltage will increase

In the existing electrode structure, a metal thin film, such as a chromium layer, is designed between the aluminum layer and the surface of the GaN epitaxial layer, which can not only ensure the adhesion of the electrode, but also reduce the voltage, but this thin film will generate light. Absorption, which affects the luminous efficiency of the LED

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