The choice of substrate materials is a primary consideration for the fabrication of LED chips . Which suitable substrate should be used depends on the requirements of the device and the LED device. There are currently three materials available on the market as substrates:
Sapphire (Al2O3)
2. Silicon (Si)
3. Silicon Carbide (SiC)
Sapphire substrate
Typically, epitaxial layers of GaN-based materials and devices are primarily grown on sapphire substrates. Sapphire substrates have many advantages: First, the production technology of sapphire substrate is mature and the device quality is good. Secondly, sapphire has good stability and can be used in high temperature growth process. Finally, sapphire has high mechanical strength and is easy to handle. And cleaning. Therefore, most processes generally use sapphire as the substrate. Figure 1 illustrates an LED chip made using a sapphire substrate.
Figure 1 LED chip with sapphire as substrate
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