Photonic quasicrystal graph sapphire substrate and manufacturing method thereof and light emitting diode and preparation method thereof

Abstract

The invention relates to a sapphire substrate and a manufacturing method thereof and a light emitting diode adopting the sapphire substrate and a preparation method thereof. The surface of the sapphire substrate is provided with a graph structure of a photonic quasicrystal structure. The proportion of the area of a C surface of the sapphire substrate, which is exposed in the graph structure, in the whole bottom area of the sapphire substrate is low. The surface of the sapphire substrate is provided with the graph structure of the photonic quasicrystal structure; the graph structure is formed in a mode that sub regions are periodically arrayed and has the lattice constant of 0.2 to 5mum; a space between each two adjacent sub regions is of a V shape or a similar V shape; the sub regions extend to the side wall of the C surface of the sapphire substrate and are at an angle of 25 to 60 degrees with the C surface of the sapphire substrate; and the proportion of the C surface of the sapphire substrate, which is exposed in the graph structure, is lower than 20 percent. The manufacturing method of the sapphire substrate comprises the following steps of: forming the photonic crystal structure on the surface of the sapphire substrate; and then carrying out anisotropic etching on the side wall of the photonic crystal structure by using a phosphoric acid / sulphuric acid mixed solution so as to form the photonic quasicrystal graph structure.

Description

technical field [0001] The invention relates to a sapphire substrate with a quasi-photon crystal pattern and a manufacturing method thereof, a light-emitting diode and a manufacturing method thereof. Background technique [0002] Light-emitting diodes based on III-nitride semiconductor materials (GaN, AlN, InN and their alloys) have the advantages of small size, long life, and high efficiency. They are used in general lighting, traffic indication, outdoor full-color display, LCD backlight, household It has broad application prospects in many fields such as electrical indicator lights. Compared with silicon carbide (SiC) and silicon (Si) substrates, epitaxial GaN-based LED materials on sapphire substrates have the advantages of high technological maturity, low cost, and large-scale production, and have been widely adopted by the industry. [0003] Due to the difference in lattice constant and thermal expansion coefficient between the sapphire substrate and GaN-based LED mate...

AI Technical Summary

Problems solved by technology

However, photonic crystal pattern substrates still have several disadvantages: First, the geometric dimensions of photonic crystals are all on the sub-micron scale. In addition to demanding photonic technology, voids are easily formed during epitaxial growth, which increases the cost of LED chips. Thermal resistance, which limits the further improvement of LED optical power

However, the roughening process depends on the defect density of the GaN material. With the continuous improvement of the quality of GaN epitaxial materials, the effect of the roughening process on improving the light extraction efficiency is becoming more and more limited.

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