High-purity single crystal sapphire substrate

Product Description

Led sapphire substrate has the characteristics of high sound velocity, high temperature resistance, corrosion resistance, high hardness, high light transmittance, and high melting point (2045°C). It is a very difficult material to process, so it is often used as a photoelectric element s material. At present, the quality of ultra-high-brightness white/blue LEDs depends on the material quality of gallium nitride epitaxy (GaN), and the quality of gallium nitride epitaxy is closely related to the surface processing quality of the sapphire substrate used.

Technical Specification

Precautions

1. The structure matching of the substrate and the epitaxial film: the crystal structure of the epitaxial material and the substrate material are the same or similar, the lattice constant mismatch is small, the crystallization performance is good, and the defect density is low;

2. The matching of the thermal expansion coefficient of the substrate and the epitaxial film: the matching of the thermal expansion coefficient is very important. The large difference in the thermal expansion coefficient of the epitaxial film and the substrate material may not only reduce the quality of the epitaxial film, but also cause heating during device operation. And cause damage to the device;

3. The chemical stability of the substrate and the epitaxial film is matched: the substrate material must have good chemical stability, and it is not easy to decompose and corrode in the temperature and atmosphere of the epitaxial growth, and the quality of the epitaxial film cannot be reduced due to the chemical reaction with the epitaxial film ;

4. The degree of difficulty of material preparation and the level of cost: Taking into account the needs of industrial development, the preparation of substrate materials has simple requirements and the cost should not be high. The size of the substrate is generally not less than 2 inches.

Currently, there are many substrate materials used for GaN-based LEDs, but there are only two substrates that can be used for commercialization, namely sapphire and silicon carbide substrates.