Liquid Phase Epitaxy (LPE) is a method to grow semiconductor crystal layers from the melt on solid substrates.

This happens at temperatures well below the melting point of the deposited semiconductor. The semiconductor is dissolved in the melt of another material.

At conditions that are close to the equilibrium between dissolution and deposition the deposition of the semiconductor crystal on the substrate is slowly and uniform.

The equilibrium conditions depend very much on the temperature and on the concentration of the dissolved semiconductor in the melt.

The growth of the layer from the liquid phase can be controlled by a forced cooling of the melt. Impurity introduction can be strongly reduced.

Doping can be achieved by the addition of dopants.

In the case of a horizontal tool for liquid phase epitaxy the melt or the melts are brought in contact with the substrate(s) by a sliding boat system.

When the dedicated process is finished the next melt can be brought in contact with the next substrate.

This way, it is possible to grow multi-layer stacks in an easy way. Depending on the set-up of the system one or several wafer can be processed at the same time.

The melt volume to substrate surface area ratio is small, and the melt needs to be refreshed after each growth experiment.