Epitaxial growth is a process used to grow a high-quality crystalline thin film on a substrate, typically a semiconductor material. In this process, the newly grown thin film adopts the lattice structure of the substrate crystal, resulting in a highly ordered single-crystal film. Epitaxial growth is essential for manufacturing semiconductor materials with specific properties, such as high electron mobility, low defect density, and excellent optoelectronic characteristics.
Various techniques can be employed for epitaxial growth, including:
Liquid Phase Epitaxy (LPE): In this method, the substrate material is immersed in a solution containing dissolved source material. As the solution cools, the source material deposits on the substrate, forming a crystalline thin film.
Vapor Phase Epitaxy (VPE): Vapor phase epitaxy encompasses Chemical Vapor Deposition (CVD) and Metal-Organic Chemical Vapor Deposition (MOCVD). In these methods, the source material is transported to the substrate surface in gaseous form and undergoes a chemical reaction at appropriate temperatures and pressures, forming a crystalline thin film.
Molecular Beam Epitaxy (MBE): In this technique, the source material is irradiated onto the substrate surface in the form of molecular beams under high vacuum conditions. The molecular beams react with the substrate surface, forming a high-quality crystalline thin film.
Epitaxial growth techniques play a crucial role in the manufacturing of semiconductor devices, such as high-speed electronic devices, optoelectronic devices, and solar cells. Through epitaxial growth, heterostructures between different materials can be achieved, enabling new device functionalities and performance optimization.