liquid-phase epitaxy abbr., LPE (rus. эпитаксия, жидкофазная) — a variation of epitaxy as one of technological methods to fabricate multilayered AlGaAs/GaAs semiconductor heterostructures.

Description

The first stage of liquid phase epitaxy includes the preparation of a mixture (batch) of the substance to grow the layers, a dopant, which can be donor or acceptor, and a solvent metal with a low melting point and good miscibility with the substrate material (Ga, Sn, Pb). The process takes place in the nitrogen and hydrogen atmosphere (to reduce the oxide films on the substrate or melt surface) or in vacuum after pre-reduction of the surface oxide film. The melt is applied onto the substrate surface (e.g., GaAs (100)), which partially dissolves the surface and removes contamination and defects. After exposing it to the maximum temperature of about 1200 K, the system is slowly cooled down, the melt grows supersaturated (whereas it was saturated) and the excess of the semiconductor is deposited on the substrate, which acts as a seed.

The main factors influencing the quality and properties of epitaxial layers are the initial equilibrium temperature and the cooling rate of the melt, the volume ratio of the melt and the contact area between the substrate surface and the melt, the nature of the solvent and the solute, and the substrate surface condition. Epitaxial growth of semiconductor heterostructures from the liquid phase has several advantages in producing highly-doped layers and p-n-junctions compared with vapour phase epitaxy.

Author

  • Gusev Alexander I.

Source

  1. Gusev A. I. Nanomaterials, Nanostructures, and Nanotechnologies (in Russian) // Fizmatlit, Moscow (2007) - 416 pp.

Contact us