A temperature gradient cell for liquid phase epitaxial growth of GaAs

A liquid phase epitaxial growth cell designed to produce a temperature gradient normal to the substrate while maintaining a very uniform temperature in the transverse direction is described. The temperature gradient appears to increase the density of nuclei during the initial phase of growth, improving the surface smoothness of the layer. With a gradient of 10 °C/cm, the cell consistently yields high quality GaAs layers that are optically smooth, and are uniform and controllable in thickness from 0.2 μm to 20 μm.