Since a molecular-beam apparatus was first successfully used by Cho and Arthur in the late 1960s to crystallize and investigate GaAs epilayers, high vacuum epitaxial growth techniques using particle beams have developed rapidly. This development accelerated when different semiconductor devices with quantum­ well structures were invented in the 1970s. The important implementation of these structures in devices like quantum-well lasers, high electron mobility tran­ sistors or superlattice avalanche photodiodes gave added impetus to research work and to increasing production aims. Coincident with this development, orig­ inal research papers and reviews devoted to problems concerning these growth techniques have also rapidly grown in number, and in addition