Method for growing epitaxial wafer of GaN-based light emitting diode

Abstract

The invention discloses a method for growing an epitaxial wafer of a GaN-based light emitting diode, and belongs to the field of a light emitting diode. The method comprises successively growing a buffer layer, an N-type layer, a multi-quantum well layer and a P-type layer on a substrate, wherein the P-type layer is grown by use of a high-pressure low-speed growth mode, the growth pressure of the P-type layer is 400torr to 760torr, the flow of TMGa is lower than 90sccm, the flow of TEGa is lower than 2000sccm, and the thickness of the P-type layer is 10nm to 60nm. According to the invention, through adoption of high-pressure low-speed growth, the crystal quality is quite good, the defect density caused by crystal lattice mismatch is substantially reduced, electric leakage channels between the NP layers are reduced, the current expansion capability of the NP layers is better, breakdown points are reduced, the antistatic capability of the epitaxial wafer is enhanced, requirements are met simply by growing a quite thin P-type layer, the light absorption amount of the P-type layer with a quite small thickness is smaller, and the light emitting amount of the front surface of a chip and the light emitting efficiency of a device are guaranteed.

Description

technical field [0001] The invention relates to the field of light-emitting diodes, in particular to a method for growing GaN-based light-emitting diode epitaxial wafers. Background technique [0002] LED (Light Emitting Diode, light-emitting diode), especially GaN-based LED devices, has the advantages of small size, high efficiency, and long life, and is widely used in traffic lights, full-color displays, LCD screen backlights, automotive instruments and interior decoration. lights etc. [0003] The existing GaN-based LED epitaxial wafer mainly includes a buffer layer, an N-type layer, a multi-quantum well layer, a P-type layer and a P-type contact layer grown on the substrate in sequence, wherein the multi-quantum well layer includes InGaN quantum wells layer and GaN quantum barrier layer, usually, the growth pressure of the P-type layer will not be higher than 200torr, the crystal quality of the P-type layer grown by this low-pressure growth method is poor, and the latti...

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Problems solved by technology

[0003] The existing GaN-based LED epitaxial wafer mainly includes a buffer layer, an N-type layer, a multi-quantum well layer, a P-type layer and a P-type contact layer grown on the substrate in sequence, wherein the multi-quantum well layer includes InGaN quantum wells layer and GaN quantum barrier layer, usually, the growth pressure of the P-type layer will not be higher than 200torr, the crystal quality of the P-type layer grown by this low-pressure growth method is poor, and the lattice mismatch between the substrate and the epitaxial wafer is caused The defect density, and the defect density caused by the lattice mismatch between the InGaN quantum well layer and the GaN quantum barrier layer in the MQW layer, will be further amplified in the P-type layer, thereby increasing the NP(N-type layer The leakage channel between the NP layer and the P-type layer), the current spreading ability of the NP layer becomes weaker, the breakdown point increases, and the antistatic ability of the epitaxial wafer is relatively poor. In order to ensure the antistatic ability of the LED device, the P-type layer is usually However, due to the light-absorbing characteristics of the P-type layer, the P-type layer with a thickness of not less than 80nm will absorb more light, which will reduce the amount of light emitted from the front of the chip and reduce the device’s performance. Luminous efficiency

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