A novel nonvolatile memory based on self-organized quantum dots

A novel type of memory based on self-organized quantum dots (QDs) is presented, which merges the advantages of the most important semiconductor memories, the dynamic random access memory (DRAM) and the Flash. A nonvolatile memory with fast access times and good endurance (>10¹⁵ write/erase cycles) as an ultimate solution seems possible. A storage time of 1.6 s at 300 K in InAs/GaAs QDs with an additional Al_0.9Ga_0.1As barrier is demonstrated and a retention time of 10⁶ years is predicted for GaSb QDs in an AlAs matrix. A minimum write time of 6 ns is obtained for InAs/GaAs QDs. This value is already in the order of the access time of a DRAM cell and at the moment limited by the RC low pass of the device. An erase time of milliseconds is shown in first measurements on GaSb/GaAs QDs at . Faster write/erase times below even at room temperature are expected for improved device structures.