Vertical GaN-based LED chip and manufacture method thereof

Abstract

The invention provides a vertical GaN-based LED chip and a manufacture method thereof. The chip comprises a substrate, N type GaN, a quantum well active layer, P type GaN, a current expansion layer, a metal mirror and a conductive substrate; a P electrode is manufactured on the conductive substrate; a window directly toward a N type GaN layer is arranged on the substrate; a layer of metal is evaporated at each side in the window; a N electrode is led out from the metal layer. The manufacture method comprises the following steps: epitaxially growing the N type GaN, the quantum well active layer, the P type GaN and the current expansion layer on a sapphire or 6H-SiC transparent substrate from bottom to top in sequence according to the conventional method; the metal mirror is manufactured onthe current expansion layer; the conductive substrate is welded on the metal mirror; the window directly toward the N type GaN layer is processed; the metal layer is evaporated at each side in the window and the N electrode is led out from the metal layer. The invention reduces the influence of instable factors in the technological process. The GaN-based LED chip is high in utilization ratio of effective light-emitting area, good in current expansion and good in heat dissipation of tube cores.

Description

technical field

[0001] The invention relates to a GaN-based light-emitting diode (LED) chip and a preparation method thereof, belonging to the technical field of optoelectronic devices. Background technique

[0002] Sapphire substrate has the advantages of mature production technology, good device quality, high stability, high temperature resistance growth process, high mechanical strength, easy handling and cleaning, etc., and has become the most widely used substrate for growing GaN-based LED epitaxial layer substrates. However, the sapphire substrate has lattice mismatch and thermal stress mismatch, which cause a large number of defects in the epitaxial layer. At the same time, sapphire is an insulator, and its resistivity at room temperature is greater than 10. 11 Ω·cm, unable to make conductive electrodes, such as figure 1 As shown, the n-type and p-type electrodes have to be made on the upper surface of the epitaxial layer, so a vertically structured LED chip cannot b...

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