EFFECTS OF IN PROFILE ON MATERIAL AND DEVICE PROPERTIES OF ALGAAS INGAAS/GAAS HIGH-ELECTRON-MOBILITY TRANSISTORS/

The molecular-beam-epitaxial growth of InxGa1-xAs on GaAs or AlyGa1-yA s leads to a variation of In content with depth, due to In segregation . However, by predepositing In at the beginning of ZnxGa1-xAs growth, and also thermally removing the excess In at the end, we can produce a layer with the ideal ''square'' In profile. We find that the performa nce of AlyGa1-yAs/InxGa1-xAs/GaAs high electron mobility transistors i s most enhanced by the predeposition step alone. (C) 1996 American Ins titute of Physics.