Epitaxial structure capable of improving light effect of large-sized chip and growing method thereof

Abstract

The invention provides a preparation method for an epitaxial structure capable of improving the light effect of a large-sized chip. The preparation method comprises the following steps: growing a GaN buffer layer on a PSS substrate; growing a UGaN layer on the GaN buffer layer; growing a Si-doped N type GaN layer on the U type GaN layer; alternately growing to form a first NAlGaN layer doped with Si and Al and a first UGaN layer not doped with Si and alternately growing for 38 to 40 cycles; alternately growing to form a second NAlGaN layer doped with Si and Al and a second UGaN layer not doped with Si and alternately growing for 25 to 26 cycles; alternately growing to form a third NAlGaN layer doped with Si and Al and a third UGaN layer not doped with Si and alternately growing for 15 to 16 cycles; and periodically growing an active layer MQW and a PGaN layer. By adopting the method that a NAlGaN/NGaN superlattice structure replaces the traditional N type GaN layer (NGaN), the external quantum luminous efficiency of a light-emitting diode (LED) is improved effectively, so that the device can increase the mobility ratio of electrons, reduce the forward voltage of the large-sized chip and improve the luminous efficiency.

Description

technical field [0001] The invention relates to an LED epitaxial structure and a preparation method thereof. The traditional N-type GaN layer (NGaN) is replaced by a NAlGaN / NGaN superlattice, so that the device can improve the mobility of electrons, reduce the voltage of small and medium sizes, and reduce the voltage of large sizes. The light effect of the chip. Background technique [0002] Now on the market, large-size high-power chips with a specification of 45mil*45mil are used in street lighting, and small and medium-sized chips with a size of 10mil*23mil are used in backlighting. The heat dissipation of large-sized chips is an important indicator. The luminous performance of large-sized chips is no longer defined by high lumens. Now the market value of high-power is oriented to lumens / (watt*unit price), and small and medium-sized chips do not need to consider heat dissipation. Market value Oriented as lumens / unit price; [0003] At present, there are many epitaxial g...

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Problems solved by technology

[0011] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a method for preparing an epitaxial structure that improves the light efficiency of a large-scale chip, which is used to solve the problem that the epitaxial str...

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