Multi-day dynamic storage of holes at the AlAs/GaAs interface

We have used a deep-depletion capacitance-voltage (CV) technique to measure the storage time of holes in AlAs/n-GaAs MIS capacitors in the dark. We measure a storage time of 75 s at 175 K, increasing to 500 min at 140 K. At 77 K, the storage time is greater than 220 h. These values are far in excess of what is needed to make a one-transistor dynamic RAM for the MODFET technology.