Homoepitaxy: The substrate and epitaxial layer are made of the same material (e.g., silicon grown on silicon). It is used to improve material purity or adjust doping concentration.
Heteroepitaxy: The substrate and epitaxial layer are made of different materials. It is necessary to address issues such as lattice mismatch and differences in thermal expansion coefficients.
Vapor Phase Epitaxy (VPE)
Chemical Vapor Deposition (CVD): Thin films are deposited on the substrate surface via chemical reactions. For example, silicon epitaxy commonly uses systems such as SiCl₄/H₂ or SiH₄/H₂.
Metal-Organic Chemical Vapor Deposition (MOCVD): It is used for the epitaxy of III-V group compounds (e.g., GaAs, InP) and nitrides (e.g., GaN), enabling the growth of high-quality optoelectronic device materials.
Molecular Beam Epitaxy (MBE)
Under an ultra-high vacuum environment, atomic or molecular beams are directly ejected onto the substrate surface, achieving atomic-level control. It is suitable for ultra-thin layers and quantum well structures.
Liquid Phase Epitaxy (LPE)
Molten materials undergo cooling and crystallization on the substrate surface. It is commonly used in infrared detectors (e.g., HgCdTe) and early-stage LED manufacturing.
Semiconductor Devices: Silicon epitaxy is used in high-frequency transistors and power devices; SiC/GaN epitaxy is applied in high-voltage and high-temperature devices.
Optoelectronics: Laser diodes (LD), light-emitting diodes (LED), and detectors.
Integrated Circuits: Silicon-on-Insulator (SOI) and epitaxial silicon/germanium-silicon channels in FinFETs.
New Materials: Epitaxial growth of two-dimensional (2D) materials (e.g., graphene) and topological insulators.
English