A kind of preparation method of Gan-based LED chip

Abstract

A method for preparing a GaN-based LED chip relates to an LED chip. The invention provides a method for preparing a GaN-based LED chip which not only has obvious effect, is easy to operate, is compatible with conventional device technology, but also has low series resistance and good P-type ohmic contact. Deposit a layer of metal Zn film on the surface of LED epitaxial wafer P-GaN by sputtering or evaporation; irradiate the Zn / P-GaN surface of the sample with a laser; etch away the remaining Zn on the surface of the sample, clean and dry; The processed sample is etched by ICP to expose the n-type GaN layer, photolithography and sputtering Ti / Al metal layer, after peeling off to form an n-type electrode, annealing; the sample is photolithography again and Ni / Au metal is sputtered on the surface Layer, after peeling off to form a p-type electrode, annealed.

Description

technical field [0001] The invention relates to an LED chip, in particular to a method for preparing a GaN-based LED chip by laser-induced doping Zn. Background technique [0002] GaN-based light-emitting diodes (LEDs) have been widely used in digital and image display fields due to their advantages in high efficiency, energy saving, and environmental protection. In recent years, due to breakthroughs in the research of GaN-based materials, high-efficiency white and blue LEDs have been developed, which can not only be used in the field of large-screen color display, but also have the potential to replace existing incandescent lamps, fluorescent lamps and other lighting projects. into people's lives. However, so far, GaN-based LED devices still have many technical problems that have not been fully resolved. Among them, the most important problems restricting their development are the difficulty in achieving a high effective doping concentration of P-GaN and the preparation of...

AI Technical Summary

Problems solved by technology

However, so far, GaN-based LED devices still have many technical problems that have not been fully resolved. Among them, the most important problems restricting their development are the difficulty in achieving a high effective doping concentration of P-GaN and the preparation of a good P-type GaN ohmic contact. Difficult to wait

Generally, P-GaN doping of GaN-based LED epitaxial wafers is generally doped with Mg during MOCVD growth, and then activated by high-temperature annealing; or ion implantation high-temperature annealing, co-doping technology, etc.; but these technologies can do The P-type effective doping concentration of the GaN material is generally only 10 17 cm -3 magnitude

The P-type effective doping concentration of GaN materials is not high. The main reasons are as follows: when GaN is grown by MOCVD, the acceptor Mg easily forms an electrically neutral Mg-H complex with H, so that Mg cannot effectively It replaces Ga sites; secondly, N vacancies are easy to be generated when GaN is grown, and N vacancies are the donor source, so the GaN material is n-type without doping; in addition, the energy level of Mg in GaN materials is relatively deep, and generally the shallowest energy level also has about 170mev, difficult to ionize at room temperature

P-type effective doping concentration is not high, it is difficult to prepare a good P-type ohmic contact

For GaN-based LED devices, poor P-type ohmic contact increases the series resistance of the device

The higher P-type series resistance not only reduces the heat generation and carrier injection efficiency of the LED device, but also causes the device to generate heat during operation, reducing the luminous efficiency of the device and reducing the reliability of the device, thereby shortening the life of the device.

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