LED (light-emitting diode) epitaxial structure capable of increasing LED backward impedance and preparation method thereof

Abstract

The invention provides an LED (light-emitting diode) structure capable of increasing LED backward impedance and a preparation method. The method comprises the following steps of pretreating a substrate at a high temperature in a hydrogen atmosphere, and sequentially growing a buffer layer, a non-doped GaN layer, an n type GaN layer, a multi-quantum well active layer, a p type GaN layer and a p type contact layer on the surface of the substrate, wherein the multi-quantum well active layer consists of at least two sections of multi-quantum well active layers, and a low-temperature non-doped GaN or AlGaN layer is inserted between the sections of the multi-quantum well active layer. The non-doped GaN or AlGaN layer is inserted into the multi-quantum well active layers, so that the LED backward impedance can be effectively increased, the backward creepage of an LED is reduced, and the reliability of the LED is increased.

Description

technical field [0001] The invention belongs to the field of LED epitaxial technology growth, and in particular relates to an epitaxial structure and a manufacturing method for improving LED brightness. Background technique [0002] Light Emitting Diode (LED, Light Emitting Diode) has the advantages of longevity, energy saving, and environmental protection. In recent years, LED has played an increasingly important role in the fields of large-screen color display, traffic signal lights, and lighting. However, in order to be more widely used in the field of full-color display and lighting, the reverse impedance of LED needs to be further improved. [0003] When a diode is working, it generally has current directionality in both forward and reverse directions. When the applied reverse voltage exceeds a certain value, the reverse current will suddenly increase. This phenomenon is called electrical breakdown. The critical voltage that causes electrical breakdown is called the di...

AI Technical Summary

Problems solved by technology

Studies have shown that V-type defects originate from threading dislocations, and there is an enrichment of In components near the defects. These defects will cause leakage and reduce the impedance of LEDs.

If the LED is working in the forward direction, the leakage is small and has little impact on the electrical performance, but when the LED is working in the reverse direction, the leakage has a greater impact at this time, which seriously affects the reliability of the LED and reduces the reliability of the LED.

[0005] Usually, in order to ensure the brightness of the LED, 3-20 periods of multi-quantum wells are grown. After growing to a certain period of quantum wells, V-type defects appear on the surface. If the multi-quantum well active layer continues to grow, the V-type defects will continue to change. large, which seriously affects the reverse impedance of the LED; the existing patents seldom consider this problem, and they continue to grow the multi-quantum well active region, such as patent 201410369108.8 MQW includes InGaN / InGaN MQW and InGaN / AlGaN MQW, but only Considering that the MQW is divided into two sections to increase the concentration of electrons and holes in the quantum wells, some of the quantum wells use AlGaN barrier layers, as is the case in patent 201310652175.6, which uses AlGaN as the barrier layer to reduce the Droop negative effect of the device, but does not Does not take into account the reverse impedance characteristics of the LED

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