Epitaxial wafer of light emitting diode and preparation method thereof

Abstract

The invention provides an epitaxial wafer of a light emitting diode and a preparation method thereof, and belongs to the technical field of photoelectron manufacturing. The preparation method comprises the following steps of: providing a substrate; and sequentially and epitaxially growing a high-temperature AlN buffer layer, a transition layer, an n-type AlGaN layer, a multi-quantum well layer and a p-type layer on the substrate, wherein the transition layer is of a periodic structure, the periodic structure comprises AlN layers and AlGaN layers which are alternately stacked, and the growth pressure of each AlGaN layer is gradually reduced in the growth direction of an epitaxial wafer. The AlN layer in the transition layer can promote dislocation defect bending extending from the high-temperature AlN buffer layer and increase the dislocation annihilation probability, so that the purpose of reducing dislocation defects is achieved, the growth pressure of the first growing AlGaN layer is high, three-dimensional island-shaped growth of the AlGaN layer is promoted, and the growth pressure of the later growing AlGaN layer is low, so that the AlGaN layer is gradually transited to two-dimensional growth from three-dimensional growth, the dislocation density is reduced and the crystal quality is improved.

Description

technical field [0001] The disclosure relates to the technical field of optoelectronic manufacturing, in particular to an epitaxial wafer of a light emitting diode and a preparation method thereof. Background technique [0002] Light Emitting Diode (English: Light Emitting Diode, referred to as: LED), as a very influential new product in the optoelectronics industry, has the characteristics of small size, long service life, colorful colors, and low energy consumption. It is widely used in lighting, display screens , signal lights, backlight, toys and other fields. The core structure of the LED is the epitaxial wafer, and the production of the epitaxial wafer has a great influence on the photoelectric characteristics of the LED. [0003] Epitaxial wafers generally include buffer layers, n-type layers, multiple quantum well layers, and p-type layers. The n-type layer in the epitaxial wafer of the ultraviolet light emitting diode is usually an AlGaN layer. [0004] At presen...

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Problems solved by technology

[0004] At present, the epitaxial growth technology of ultraviolet LED is not mature enough, and there are many dislocation defects in the grown epitaxial wafer, resulting in poor crystal quality and low luminous efficiency.

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