A light-emitting diode epitaxial wafer and its manufacturing method

Abstract

The invention discloses a light-emitting diode (LED) epitaxial wafer and a manufacturing method thereof and belongs to the technical field of semiconductors. The light-emitting diode epitaxial wafer comprises a substrate and also comprises a low-temperature buffer layer, an undoped GaN layer, an N-type layer, a multiple-quantum well layer, an electron blocking layer and a P-type GaN layer which are sequentially stacked on the substrate, and the light-emitting diode epitaxial wafer further comprises an AlN layer arranged on the P-type GaN layer. The forbidden bandwidth of the AlN material is larger than that of the GaN material. After the AlN layer is grown on an upper surface of the P-type GaN layer, the Fermi levels of two materials are aligned, an energy band on the upper surface of theP-type GaN layer is regulated, the bending direction of the upper surface of the P-type GaN layer changes from upward to downward, an original hole potential energy valley at that position disappears,the hole is not limited to the surface anymore, therefore, the movement of the hole to the direction of a multiple-quantum well is promoted, the injection efficiency of the hole is improved, and therefore, the luminous efficiency of an LED is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a light-emitting diode epitaxial wafer and a manufacturing method thereof. Background technique [0002] LED (Light Emitting Diode, Light Emitting Diode) is a semiconductor electronic component that can emit light. As an efficient, environmentally friendly and green new solid-state lighting source, it is being rapidly and widely used, such as traffic lights, car interior and exterior lights, urban landscape lighting, mobile phone backlights, etc. [0003] Epitaxial wafers are the main components of LEDs. The existing GaN-based LED epitaxial wafers include substrates and low-temperature buffer layers stacked on the substrates, undoped GaN layers, N-type layers, multiple quantum well layers, electronic barrier layer and P-type layer. The N-type layer is a GaN layer doped with Si, which can provide electrons, and the P-type layer is a GaN layer doped with Mg, which can prov...

AI Technical Summary

Problems solved by technology

[0005] Due to the spontaneous polarization inside the GaN material, induced negative charges will appear on the upper surface of GaN, and these induced negative charges will cause the energy band on the GaN surface to bend upwards. In the LED epitaxial wafer, the upward-bent valence band on the upper surface of the P-type GaN layer For holes, it is a "potential energy valley". Part of the holes will be confined in this "potential energy valley". It is difficult to inject into the multi-quantum well light-emitting area, which reduces the hole injection efficiency, thereby reducing the luminous efficiency of the LED.

Images