COMPOUND SEMICONDUCTOR GROWTH BY METALLORGANIC MOLECULAR-BEAM EPITAXY (MOMBE)

The replacement of elemental sources with gaseous precursors allows many of the advantages of metallorganic chemical vapour deposition (MOCVD) to be combined with those of molecular beam epitaxy (MBE). This technique has come to be known as metallorganic molecular beam epitaxy (MOMBE) or alternatively chemical beam epitaxy (CBE). While retaining many desirable properties of the parent techniques, however, new challenges are created by this combination, particularly in the area of growth chemistry. This article will review the status of semiconductor deposition by MOMBE, paying particular attention to the areas of impurity contamination and precursor selection. At present, MOMBE has been applied primarily to deposition of III-V materials; consequently this article will focus on these materials. Many of the issues reviewed in this article are applicable to other material systems as well. Basic equipment design, growth efficiency, contamination control, dopant incorporation, selective epitaxy and the role of hydrogen are all discussed.