Principle of the Technology
The MOVPE (metal organic vapour phase epitaxy) technique is suitable for compound semiconductors preparation and uses chemical elements thermally decomposed from precursors – metalorganic molecules and hydrides. The decomposition takes place in the reactor on the top of the inductively heated graphite susceptor, where substrate is situated. The carrier gas for metalorganic molecules is mostly palladium-purified hydrogen with impurity concentration less than 1 ppb. The advantage of this technique for laboratory purposes is the possibility to prepare a broad spectrum of semiconductor materials in one apparatus. This technology does not require high vacuum, therefore it is preferred by the industry.
The possible diagnostic performed during epitaxial growth makes the use of different surface reflectivities in perpendicular crystallographic directions for incoming light (RAS - reflectance anisotropy spectroscopy). This enables the growth monitoring of individual atomic layers as well as the composition and the quality of epitaxial ones.
MOVPE technology, together with molecular beam epitaxy (MBE), is suitable for the preparation of heterostructures also on the nanoscale.