Phosphorous effusion apparatus and method for Molecular Beam Epitaxy

Abstract

A phosphorus effusion cell for molecular beam epitaxy consists of a vessel in which, by sublimation of red phosphorus, the vapour of this element is produced, the vessel being closed by means of a vacuum-tight valve (3) which regulates its flow. In the vessel, there are two zones having different temperatures, one for (1) of red phosphorus and another (2) for condensation and re-evaporation of white phosphorus, both zones being thermally insulated by means of reflecting screens (6) which prevent the temperature of the heating resistance from having to reach temperatures above 350 DEG C. The valve, intermittent closing of which regulates the effusion of phosphorus vapour, is at a temperature slightly above that of the thermostated zone of condensation/reevaporation of white phosphorus. It finds application in the manufacture of semiconducting structures.