Gallium nitride based light-emitting diode (LED) epitaxial wafer and growth method thereof

Abstract

The invention provides a gallium nitride based light-emitting diode (LED) epitaxial wafer and a growth method thereof. From down to up, the structure of the epitaxial wafer successively comprises a substrate, a gallium nitride based buffer layer, a non-doped gallium nitride layer, an n type gallium nitride layer, a multi-quantum well layer, a p type AlGaN layer, a p type gallium nitride layer and a contact layer. The epitaxial wafer is characterized in that the contact layer is an n type InxGa1-xN layer, or a p type InxGa1-xN layer, wherein x is a molar coefficient and is more than 0 and less than 1. The modulated doped contact layer epitaxial structure is obtained through adding an In component and a doped layer with gradually changed concentration, thereby relieving the impact of static electricity on a gallium nitride LED and improving the tolerance capability of the LED on the static electricity. According to a standard chip process, the chip with 300*300 mu m<2> is manufactured, and the electronic static discharge (ESD) yield of the chip in reverse 4000 V is above 90%.

Description

technical field [0001] The present invention relates to an LED epitaxial wafer and a growth method thereof, in particular to a gallium nitride-based LED epitaxial wafer and a growth method thereof with improved antistatic capability, belonging to the technical field of semiconductors. Background technique [0002] Gallium nitride-based materials, including InGaN, GaN, and AlGaN alloys, are direct bandgap semiconductors, and the bandgap is continuously adjustable from 1.8 to 6.2eV. It is the preferred material for the production of high-brightness blue, green, and white LEDs, and is widely used in Full-color large-screen display, LCD backlight, signal lights, lighting and other fields. [0003] GaN LED devices generally use ITO as the electrode, because the direct contact between ITO and pGaN is generally poor, which will cause uneven current density and excessive local current density. GaN-based materials are mostly grown on sapphire substrates. Due to the large lattice mis...

AI Technical Summary

Problems solved by technology

In order to improve the ESD of GaN-based LED devices, some institutions have introduced more complex device manufacturing methods (Chinese Patent Publication No. CN 1988119A), which increases the cost of device manufacturing

[0004] Electrostatic discharge will occur very quickly with a very high intensity. When the discharge current flows through the PN junction of the LED, the Joule heat generated will melt the local medium between the PN poles of the chip, causing a short circuit or leakage of the PN junction, resulting in a burst of LED devices. failure or latent failure

Sudden failure causes permanent failure of LED, that is, short circuit

Potential failure can degrade the performance parameters of the LED, such as increased leakage current. Generally, there is no way to cure the hidden dangers of GaN-based LEDs after being damaged by static electricity, and the deterioration of parameters leads to a vicious cycle, which eventually leads to permanent failure.

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