Baffle‐free refractory dimer arsenic source for molecular‐beam epitaxy

A refractory, two‐zone, large‐capacity, baffle‐free arsenic cracking source for molecular‐beam epitaxy is presented. The new features of this design include the use of a molybdenum tube to provide efficient cracking, a horizontal sublimator at a right‐angle geometry to the cracking section, a baffle‐free design, and the use of expanded tantalum heating filaments. High‐efficiency cracking is obtained at cracking tube temperatures between 750 and 1050 °C. Bulk GaAs and GaAs/AlGaAs heterostructures grown using this source exhibit good electrical and optical properties, with clear improvements in electrical behavior when compared to an As4 source. We believe this source design can be easily applied to other column V materials such as phosphorus and antimony.