Recent Developments In Gas Source Molecular Beam Epitaxy

Abstract

Several interesting variations of Molecular Beam Epitaxy (MBE), have been developed out of our need, in optical communications, to grow heterostructures incorporating P containing III-V compounds, most importantly in the GaInAs(P)/InP system. These come under the general heading of Gas Source Molecular Beam Epitaxy (GSMBE), and include two major variations. In the first of these the solid elemental group V sources of conventional (or Elemental Source) MBE are replaced with gaseous sources, usually arsine and phosphine, that are thermally decomposed to produce beams of group V dimers and H2 [1]. We now call this method Hydride Source MBE. In the second variation an additional modification is that the elemental group III sources of ESMBE are replaced with simple alkyl compounds of those group III elements [2]. Since those compounds are relatively volatile, beams containing their molecules can readily be generated and impinged on a heated substrate in the MBE system. We call this variation Metal Organic MBE (MOMBE). HSMBE has been shown to be a very versatile method for the investigation of a variety of heterostructures, while MOMBE appears to provide easier access to very low doping background and is potentially the most easily scalable of all of the III-V epitaxy methods for the growth of GaInAs(P)/InP heterostructures.