Arsenic atom source

Abstract

The present invention provides a source of Group V and VI atoms, and in particular arsenic atoms, usable in MBE as a growth source or a doping source. The arsenic atoms are produced in two steps. In the first step, a sublimator vaporizes solid arsenic, producing a molecular beam of arsenic tetramers and/or dimers. The molecular beam source can optionally include a cracker to produce As.sub.2 from As.sub.4. In the second step, the molecular beam impinges on a surface of a heated element, termed an atomizer, producing an output beam containing atomic arsenic. The atomizer is at a temperature above about 1200K and a pressure below about 10.sup.-3 torr or at a temperature above about 1400K and a pressure below about 10.sup.-2 torr. For other Group V and VI elements, different atomizer temperatures and pressures are used. Materials which can be used for the atomizer include tungsten, lanthanum, niobium, rhenium, molybdenum, tantalum, stainless steel, nickel, carbon, platinum, boron, silicon, ceramics and boron nitride.