LED epitaxial growth method

Abstract

The invention provides an LED epitaxial growth method for improving antistatic capability and luminous efficiency. The LED epitaxial growth method specifically comprises the steps of 1, processing a substrate; 2, growing a low-temperature buffer layer gallium nitride layer on the substrate; 3, growing an undoped gallium nitride layer; 4, growing a composite N-type layer; 5, growing a multi-quantumwell light-emitting layer; 6, growing an electron barrier layer doped with aluminum and magnesium; 7, growing a magnesium-doped high-temperature P-type gallium nitride layer; and 8, annealing in a furnace for 25-30 minutes under the conditions that the temperature is 750-800 DEG C and the pressure is 500-800mbar, closing a heating system and a gas supply system, and cooling along with the furnace. According to the epitaxial growth method, the bottom stress is greatly released, the bottom dislocation density is reduced, the gallium nitride crystal quality is improved, the current expansion isimproved, the antistatic performance of the LED is improved, and the light output power of the LED is also improved.

Description

technical field [0001] The invention relates to the technical field of LEDs, in particular to an LED epitaxial growth method. Background technique [0002] At present, the LED epitaxial structure grown by metal chemical vapor deposition method MOCVD is prone to defects of lattice mismatch between the substrate and the gallium nitride layer. The defects include point dislocations, ductile dislocations and screw dislocations. The error density is between 1×10 10 ~3×10 10 piece / m 2 , the existence of dislocations destroys the original crystal ordering of gallium nitride, and brings many negative effects on LED devices. For example, screw dislocations make the LED epitaxial structure extend from the bottom layer of the epitaxial layer to the surface of the epitaxial layer, passing through the light-emitting layer, and providing LED devices The leakage current of the LED device provides a path, and the leakage current of the LED device accelerates the aging of the device, and ...

AI Technical Summary

Problems solved by technology

[0002] At present, the LED epitaxial structure grown by metal chemical vapor deposition method MOCVD is prone to defects of lattice mismatch between the substrate and the gallium nitride layer. The defects include point dislocations, ductile dislocations and screw dislocations. The error density is between 1×10 10 ~3×10 10 piece / m 2 , the existence of dislocations destroys the original crystal ordering of gallium nitride, and brings many negative effects on LED devices. For example, screw dislocations make the LED epitaxial structure extend from the bottom layer of the epitaxial layer to the surface of the epitaxial layer, passing through the light-emitting layer, and providing LED devices The leakage current of the LED device provides a path, and the leakage current of the LED device accelerates the aging of the device, and the antistatic ability of the LED device is also greatly weakened due to the existence of dislocations.

The existing LED market requires low drive voltage for LED chips, especially at high current densities, the lower the drive voltage the better, and the higher the light efficiency the better. Solved, the dislocation density has not been effectively reduced, and when the high-density current passes through the leakage path, it is easy to cause the LED device to be broken down and damaged

[0003] In summary, there is an urgent need for an LED epitaxial growth method to solve the problem of lattice mismatch between the substrate and the gallium nitride layer existing in the existing LED epitaxial structure

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