GaN remote EPI on SiC

GaN (Gallium Nitride) Remote EPI (Epitaxy) on SiC (Silicon Carbide) substrate is a technology that involves the growth of a thin layer of GaN on top of a SiC substrate using epitaxial growth techniques. This technology is gaining popularity in the semiconductor industry due to the excellent electrical and thermal properties of GaN and SiC.

Challenges: One of the main challenges associated with GaN Remote EPI on SiC substrate is the lattice mismatch between the two materials. The lattice constant of GaN is about 3.19 Å, while that of SiC is about 4.36 Å. This large lattice mismatch can cause defects and dislocations in the GaN layer, which can degrade its electrical and optical properties.

Another challenge is the growth of a uniform and high-quality GaN layer on SiC substrates. The growth of GaN on SiC involves several complex steps, including nucleation, growth initiation, and crystal growth. The process requires precise control of temperature, gas flow, and pressure to ensure a high-quality epitaxial layer.

New approach: To address these challenges, researchers are exploring new approaches such as the use of interlayers and buffer layers to reduce the lattice mismatch between GaN and SiC. One approach involves the use of a thin layer of AlN as an interlayer between GaN and SiC. AlN has a lattice constant that is close to that of GaN, which can help to reduce the lattice mismatch and improve the quality of the GaN layer.

Another approach involves the use of a buffer layer to reduce the stress caused by the lattice mismatch between GaN and SiC. This approach involves the growth of a graded layer of GaN on SiC, which gradually changes its lattice constant to match that of GaN. This can help to reduce the defects and dislocations in the GaN layer and improve its electrical and optical properties.

Overall, GaN Remote EPI on SiC substrate is a promising technology with many potential applications in the semiconductor industry. However, further research is needed to overcome the challenges associated with this technology and to develop new approaches that can improve the quality and performance of the GaN layer on SiC substrates.