Vapor Phase Epitaxy
The vapor phase epitaxy has been developed to prepare the main semiconductor compounds of the nitrides. Vapor phase epitaxy uses a gaseous phase composed of elements of the materials to be obtained. At a fixed temperature the vapor phase precursors decompose and react at the substrate surface, giving the desired layer. Vapor phase epitaxy was initially developed using chloride and hydride compounds, and later improved by the introduction of new precursors and methodologies such as metal-organic compounds and atomic layer epitaxy. Metalorganic Vapor Phase Epitaxy is based on the principle that metalorganics and hydrides precursors are cracked on a hot substrate where the deposition takes place. These precursors are transported in the growth chamber by a carrier gas (usually hydrogen). In Atomic layer epitaxy, the precursors are introduced alternately into the growth chamber, followed by a cleaning/purge step with a carrier gas. The vapor phase epitaxial growth technique is very complex when it is viewed at the atomic scale.