Obtaining a flat area of solid amorphous boron by chemical vapor deposition

It is shown that to obtain a flat area of amorphous-boron by C.V.D., the most important conditions concern the mass transportation of the reactant vapours. When the deposition cell provides for a gas stream of high velocity normal to the substrate, the a-boron deposition is deposited regularly. The average time after which there is a notable probability of crystallization decreases sharply when the deposition temperature increases. (Auth.)