Explanation

The technology of growing thin layer of single crystal materials from supersaturated solution on the basis of a certain orientation single crystal. For example, GaAs thin layers are grown on GaAs single crystal substrates by supersaturated solutions of Ga with As as solute. Its growth driving force is the supersaUiration degree of solute in solution, and its dynamic process is solute diffusion, convection transport to the growth interface, and adsorption, reaction, migration and nucleation on the substrate surface. Its main advantages are simple growth equipment, high growth rate, safer operation compared to VPE, wide selection of dopants, and easy control of the composition and thickness of the epitaxial layer. The main drawbacks are poor surface morphology of the epitaxial layer and high requirements for matching the epitaxial layer with the substrate lattice. The growth process is divided according to the way the substrate contacts the boat: boat tilting method, crucible immersion method, reaction tube rotation method, and sliding boat method, with the latter method being the most widely used. There are temperature drop method and temperature difference method to control supersaUiration degree of solution; The former is further divided into equilibrium cooling method, subcooling method, step cooling method, and two-phase solution cooling method. liquid phase epitaxy (LPE) is one of the main processes for the industrial production of a variety of compound semiconductor epitaxial materials.

Classification