High-luminous-efficiency LED epitaxial wafer and preparation method thereof

Abstract

A high-luminous-efficiency LED epitaxial wafer comprises a sapphire substrate, a low-temperature nucleating layer, a high-temperature non-doped GaN layer, a high-temperature n type GaN layer, a surface recovery layer, a multi-quantum-well luminescent layer structure and a p type GaN layer, wherein the low-temperature nucleating layer is prepared on the sapphire substrate, the high-temperature non-doped GaN layer is prepared on the low-temperature nucleating layer, the high-temperature n type GaN layer is prepared on the high-temperature non-doped GaN layer, the surface recovery layer is prepared on the high-temperature n type GaN layer, the multi-quantum-well luminescent layer structure is prepared on the surface recovery layer, and the p type GaN layer is prepared on the multi-quantum-well luminescent layer structure. According to the invention, the GaN surface recovery layer is inserted, the growth parameter of the surface recovery layer is optimized, and surface damage caused by GaN decomposition in the cooling process is recovered; and thus, quantum wells grown on the smooth GaN surface, the interface quality of the quantum wells is improved, and the defect density of the multi quantum well region is reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices, in particular to a high-luminous-efficiency LED epitaxial wafer and a preparation method thereof. Background technique [0002] GaN-based materials are also known as Group III nitride materials (including InN, GaN, AlN, InGaN, AlGaN, etc., and their forbidden band width ranges from 0.7-6.2eV), and their spectra cover the near-infrared to deep ultraviolet bands, which are considered to be The third-generation semiconductor after Si and GaAs has important application value in the field of optoelectronics, especially GaN-based semiconductor lasers with InGaN low-dimensional structure as the active region can realize violet, blue and green laser emission, with unique Advantage. InGaN / GaN multiple quantum wells are used as the light-emitting layer and are the core structure of light-emitting devices. In order to improve the luminous efficiency of GaN-based semiconductor lasers and ligh...

AI Technical Summary

Problems solved by technology

However, this temperature is much higher than the growth temperature of the InGaN / GaN multi-quantum well region, so before growing the quantum wells, the sample needs to undergo a process of cooling from 1000 °C, and this process generally interrupts the growth, which will inevitably lead to n-type GaN Decomposition of the layer increases the surface roughness and may form more defects

According to material growth experience, whether it is the poor interface of InGaN / GaN multi-quantum wells or the many defects near the quantum well region, the luminous efficiency will be significantly reduced.

Images