Epitaxial growth method capable of improving anti-static electricity capacity of III-V class compound semiconductor LED (light emitting diode) chip

Abstract

The invention provides an epitaxial growth method capable of improving the anti-static electricity capacity of an III-V class compound semiconductor LED (light emitting diode) chip. An LED epitaxial structure comprises a GaN non-doped layer, an N-type doped GaN layer, an n-type AlGaN / GaN composite insert layer, a high-temperature P-type GaN layer and a P-type contact layer, wherein the n-type AlGaN / GaN composite insert layer specifically comprises the following steps of growing a layer of the n-type AlGaN layer of which the content of Al components is gradually increased; growing an n-type doped AlGaN layer of which the content of the Al components is constant; growing a layer of n-type AlGaN and GaN composite structural layer of which the content of the Al components is gradually reduced, and after the temperature is increased to 1,000-1,200 DEG C, growing a GaN layer. According to the epitaxial growth method, the n-type AlGaN and GaN composite structural layer with the variable content of the Al components is inserted between an N-type GaN layer and a shallow trap layer, so that breakdown of a device, which is caused by ultrahigh regional current, is effectively avoided, and the anti-static electricity capacity of the device is improved; the piezoelectric field effect of the instrument is reduced; the injection efficiency for a current carrier is improved, and the luminous efficiency of a GaN-based LED is improved.

Description

technical field [0001] The invention relates to the technical field of preparation of Group III nitride materials, in particular to an epitaxial growth method for improving the antistatic ability of Group III-V compound semiconductor LED chips. Background technique [0002] LED is the abbreviation of Light Emitting Diode in English. Its core part is a wafer composed of p-type semiconductor and n-type semiconductor. There is a transition layer between p-type semiconductor and n-type semiconductor, which is called p-n junction. In the PN junction of some semiconductor materials, when the injected minority carriers recombine with the majority carriers, the excess energy will be released in the form of light, thereby directly converting electrical energy into light energy. [0003] At present, 80% of the substrates used in the production of LEDs use sapphire (Al 2 o 3 ) substrate, however Al 2 o 3 The lattice mismatch with GaN is large and the difference in thermal expansion...

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Problems solved by technology

[0003] At present, 80% of the substrates used in the production of LEDs use sapphire (Al 2 o 3 ) substrate, however Al 2 o 3 The lattice mismatch with GaN is large and the difference in thermal expansion coefficient is relatively large. Therefore, during the epitaxial growth process, a large number of lattice defects are introduced and stress is also generated.

These dislocations tend to extend along the crystal lattice to the surface of the epitaxial wafer through the multi-quantum well region, forming threading dislocations, and the existence of a large number of dislocations makes the crystal quality of the device worse, and the local current is easy to be too large, resulting in the failure of the device. failure; and if the stress cannot be released before the quantum well active region, the compressive stress on the InGaN well layer will increase, making the quantum confinement Stark effect more obvious; gradually accumulating experiments prove that the existence of a large number of dislocations and stress limits the It further enters the high-end application market

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