Ultraviolet light emitting diode epitaxial wafer and method of making the same

Abstract

The invention discloses a UVLED (ultraviolet light emitting diode) epitaxial wafer and a manufacturing method thereof and belongs to the technical field of semiconductors. The UVLED epitaxial wafer comprises a substrate as well as a buffer layer, an undoped GaN layer, an N-type layer, a multiple quantum well layer, an electron barrier layer, a P-type layer and a P-type contact layer which are sequentially stacked on the substrate, wherein the multiple quantum well layer consists of superlattice structures with multiple cycles, and each superlattice structure comprises a GaN well layer and a BAlN barrier layer which are sequentially stacked. Compared with existing GaN / AlGaN heterojunctions, a GaN / BAlN heterojunction has smaller valence-band offset and larger conduction band offset, can better limit electrons in the GaN well layer and can improve hole migration; and a GaN / BAlN heterojunction interface has high-concentration two-dimensional electron gas, can improve the lateral transfer capability of carriers and finally improves the radiative recombination efficiency of electrons and holes, so that the light emitting efficiency of the UVLED is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to an epitaxial wafer of an ultraviolet light emitting diode and a manufacturing method thereof. Background technique [0002] UV Light Emitting Diode (UVLED for short) is a solid-state ultraviolet light source. It has many advantages such as no pollution, small size, low energy consumption, and long life. It is widely used in medical and health (such as sterilization, cancer detection, skin disease treatment, etc.) ), environmental protection (such as the rapid decomposition of pollutants such as dioxins, polychlorinated biphenyls, and pesticides, and the purification of water and air), lighting (such as white light-emitting diodes with high color rendering index) and other fields. [0003] Epitaxial wafers are an important component in the manufacture of LEDs. The existing ultraviolet light-emitting diode epitaxial wafer includes a substrate, and an undoped GaN layer, an N...

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Problems solved by technology

[0005] The energy band difference between GaN and AlGaN is small, which will lead to the weakening of the carrier confinement ability of the multi-quantum well layer, which will reduce the luminous efficiency of the LED

At the same time, the valence band shift of GaN / AlGaN heterojunction is relatively large (about 0.5eV), and the conduction band shift is small (about 1.4eV). The small shift is not conducive to confining electrons, which will lead to low internal quantum efficiency of UV LEDs

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