Light emitting diode shallow trap growing method for improving stress release and carrier storage

Abstract

The invention discloses a light emitting diode shallow trap growing method for improving stress release and current carrier storage. A low temperature shallow quantum well consisting of 5-12 cycles of InxGa1-XN(0.04<x<0.4) / GaN multiple quantum wells is grown on a Si N-doped type GaN layer, the growing mode of the multiple quantum wells is a similar funnel mode, and the mole constituent content of In in the multiple quantum wells is 5%-15%; and a low temperature luminous layer of multiple quantum wells consisting of 3-15 cycles of InyGa1-yN(x<y<1) / GaN is grown on the low temperature shallow quantum well, and the mole constituent content of In in the multiple quantum wells is 10%-50%. According to the method disclosed by the invention, the funnel-shaped structure is adopted in a shallow well, pressure can be effectively slowly released and current carriers in the SW (shallow well) can be temporarily stored through the change of gradient formed by different In concentration doping and different growing time, the speed of injecting electrons into a luminous area can be reduced, electron overflow caused by that the concentration of carriers doped in an N area is higher than that in a P area and the mobility ratio is higher is avoided particularly when an energy band is changed before injecting into MQW (multiple quantum wells).

Description

technical field [0001] The invention relates to the technical field of manufacturing gallium nitride-based semiconductor materials, in particular to a light-emitting diode shallow well growth method for improving stress release and carrier storage. Background technique [0002] In the existing GaN-based light-emitting diodes, the spontaneous polarization is caused by the dipole moment between the positive and negative charges of the GaN crystal in the multi-quantum well light-emitting diode structure of the five-three-group nitride material, and the lattice mismatch between InGaN and GaN Stress will cause piezoelectric polarization, and the polarization electric field generated by this polarization effect will cause the energy band of the multiple quantum well (Multiple Quantum Wells, MQWs) structure to deform, thereby producing the Quantum Confined Stark Effect (Quantum Confined Stark Effect) , QCSE), changing the quantum well band gap, resulting in electron overflow (Elect...

AI Technical Summary

Problems solved by technology

[0002] In the existing GaN-based light-emitting diodes, the spontaneous polarization is caused by the dipole moment between the positive and negative charges of the GaN crystal in the multi-quantum well light-emitting diode structure of the five-three-group nitride material, and the lattice mismatch between InGaN and GaN Stress will cause piezoelectric polarization, and the polarization electric field generated by this polarization effect will cause the energy band of the multiple quantum well (Multiple Quantum Wells, MQWs) structure to deform, thereby producing the Quantum Confined Stark Effect (Quantum Confined Stark Effect) , QCSE), changing the quantum well band gap, resulting in electron overflow (Electron Overflow); especially under high-power drive current, the internal leakage current of the device becomes serious, resulting in a decrease in the internal quantum efficiency, which seriously hinders the gallium nitride LED Application under high current density injection; another important reason affecting luminous efficiency is: the mobility and concentration of carriers (electrons) after N-doping are higher than those of P-doped carriers (holes) The mobility and concentration are large, especially when driven by high power and high current, it will quickly cross the quantum well region to P pole recombination, and electrons overflow the active region to form invalid current injection, resulting in non-radiative recombination, resulting in a rapid decline in light efficiency

[0003] For the stress caused by the lattice mismatch and thermal mismatch between the heterojunction epitaxial layer and the substrate, people grow a low-temperature buffer layer between the gallium nitride film and the substrate to relieve the mismatch stress. In the N-layer gallium nitride The electron blocking layer (Electron Blocking Layer, EBL) of aluminum component is inserted in to weaken the polarization effect between it and the space layer (Space Layer); while the stress and polarization effect generated in the InGaN / GaN superlattice region have no Very good release, so the shallow well region acts as a slow release region between the N region and the superlattice, which has a certain effect on the release region of this stress and the slow release of carrier (electron) storage. At present, the shallow well is a fixed well Wide cyclic growth and shallow barrier growth time before and after are too long and the density has limited effects on the stress release of multiple quantum wells and the injection, storage and output of carriers

Images