The use of computer controlled group V valved sources for interface type control in InGaSb/InAs strained layer superlattices

The purpose of this research is to demonstrate the necessity of computer co ntrolled valved group V effusion cell sources in the growth of indium galli um antimonide/indium arsenide (InGaSb/InAs). These sources allow enhanced c ontrol of the group V flux. This flux control allows the reduction of unwan ted cross contamination and complete control of the interface type. For sim ple structures, this control can be done manually, however, for complicated structures the control must be automated to allow for reproducibility and uniformity. The InGaSb/InAs strained layer superlattice (SLS) is an example of a complicated structure with hundreds of layers that requires interface type control. Arsenic incorporation with typical flux shuttering was found to be a problem in the growth of antimonide layers and limit interface typ e control. The antimony incorporation was not found to occur for the growth of arsenide layers. In addition, antimony exposure to critical interfaces did not appear to reduce the interface quality. This research demonstrates that the use of computer controlled valve sources is only required for the arsenic source when attempting to create InGaSb/InAs SLS structures.