Carrier traps in a GaAs/AlxGa1-xAs single electron transistor

We study carrier traps in a single electron transistor fabricated from a GaAs/AlxGa1-xAs heterostructure. In the heterointerface, there are many kinds of defects, which induce various trap levels in the band gap of AlxGa1-xAs or GaAs. The current through the transistor switches between two states because of trapping and detrapping of a single electron. The gate voltage dependencies of the switching indicate how the traps are spatially distributed, The possibility of the existence of a trap with multilevels is also discussed. (C) 1996 American Institute of Physics.