Light emitting diode epitaxial wafer and fabrication method thereof

Abstract

The invention discloses a light emitting diode epitaxial wafer and a fabrication method thereof, and belongs to the technical field of semiconductors. The fabrication method comprises the steps of providing a patterned sapphire substrate (PSS); forming an aluminum nitride buffer layer on a surface, on which patterns are arranged, of the PPS, wherein the aluminum nitride buffer layer comprises first parts and second parts, the first parts are arranged on the patterns, the second parts are arranged among the patterns; coating photoresist on the aluminum nitride buffer layer, wherein the thickness of the photoresist arranged on the first parts is smaller than the thickness of the photoresist arranged on the second parts; performing dry etching on the photoresist until the photoresist arranged at the tops of the first parts is removed; removing the tops of the first parts; laying a silicon dioxide material; removing the residual photoresist to form a silicon dioxide layered structure; and sequentially growing an N-type gallium nitride layer, a light emitting layer and a P-type gallium nitride layer. By the fabrication method, the epitaxial defect of a top end of the PPS caused by the aluminum nitride buffer layer can be prevented, and lattice mismatching also can be buffered by the aluminum nitride buffer layer.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a light-emitting diode epitaxial wafer and a manufacturing method thereof. Background technique [0002] A light emitting diode (English: Light Emitting Diode, referred to as: LED) is a semiconductor device that can convert electrical energy into light energy. The chip is the core component of the LED, and the chip includes an epitaxial wafer and electrodes arranged on the epitaxial wafer. [0003] The existing epitaxial wafer includes a substrate and an N-type semiconductor layer, a light-emitting layer and a P-type semiconductor layer stacked on the substrate in sequence. Wherein, the substrate is made of sapphire, and the N-type semiconductor layer, light emitting layer and P-type semiconductor layer are made of gallium nitride (GaN) material. [0004] There is a large lattice mismatch between GaN material and sapphire. In order to alleviate the lattice mismatch betw...

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Problems solved by technology

[0006] If PSS is used on the substrate, and an AlN buffer layer is set between the substrate and the GaN material, the GaN material is very weak on the AlN buffer layer because the enablement of the AlN surface is lower than that of sapphire. Easy to grow, the characteristics of gallium nitride material on the tapered slope of PSS to select the direction for lateral growth will be destroyed, unable to merge and offset the dislocations and defects caused by the lattice mismatch between gallium nitride material and sapphire, and the growth of epitaxial wafers quality will decrease

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