PAM-XIAMEN offers pattern sapphire substrate(PSS) for high brightness GaN based LED EPI growing application. The patterned sapphire substrate wafer is to grow a dry etching mask on the sapphire substrate. The mask is engraved by a standard photolithography process. Then, the sapphire is etched by ICP etching technology, and meanwhile, the mask is removed. After that, the GaN material is grown on the sapphire,so that the vertical epitaxy of the GaN material becomes the horizontal epitaxy. The details of patterned sapphire substrate are below:
1. Specifications of Patterned Sapphire Substrate
|Material||High purity monocrystallinAl2O3|
|Total thickness variation||≤10||㎛|
|Primary flat length||16.0 ±1.0||㎜|
|Primary flat orientation||A plane ±0.2|
|Front surface quality||Epitaxial ready|
|Back surface roughness||1.0 ±0.1||㎛|
|Surface orientation A||0˚off ±0.1|
|Surface orientation M||0.2˚off ±0.10|
|Surface orientation R||R9|
2. Why Choose Patterned Sapphire Substrate for LED?
On the one hand, the cone-shaped patterned sapphire substrate wafer can effectively reduce the dislocation density of the GaN epitaxial material(the patterned sapphire substrate dislocation is low), thereby reducing the non-radiative recombination of the active area, reducing the reverse leakage current, and improving the life of the LED. On the other hand, the light emitted from the active region is scattered multiple times by the interface of GaN and sapphire substrate, and the exit angle of total reflection light is changed, increasing the probability that the light of the flip-chip LED emerges from the sapphire substrate, thereby improving the extraction efficiency of the light.
In summary, the emitted light brightness of the LED grown on the nano patterned sapphire substrate is greatly improved than that of the traditional LED. The reverse leakage current is reduced, extending the life of LED.
A patterned sapphire substrate belongs to the semiconductor industry. As a high-brightness epitaxial material, it is the source material of the LED lighting industry. Meanwhile, using PSS patterned sapphire substrate wafer to grow epitaxial wafers is the most effective way to improve the brightness of the chip. It is also the best choice for the high-power and high-brightness epitaxial wafers.