Epitaxial growth is a process used to create thin films of crystalline material on a substrate. This technique allows the new layer to grow in a specific orientation that matches the underlying crystal structure, which is crucial for producing high-quality semiconductor devices. There are various methods for epitaxial growth, including Molecular Beam Epitaxy (MBE) and Metal-Organic Chemical Vapor Deposition (MOCVD). These methods enable precise control over the thickness and composition of the layers, making them essential in the fabrication of advanced materials used in electronics and optoelectronics.