Memory phenomena in heterojunction structures with variable Gap Injector.

The physics of a new GaAs/AlGaAs floating-gate memory device is investigated. Long electron storage times (e.g., 4 hours at 140K) have been measured and linked to the indirect nature of the GaAs-AlAs conduction band discontinuity. A simple analysis of the structure shows that tunneling-assisted thermionic emission processes and band-structure effects, not included in standard emission theories, must be considered to properly account for the observed long retention times.