Long-time storage of surface-acoustic-wave signals in zinc-oxide–on–silicon structure

A surface-acoustic-wave memory device with very long storage time is demonstrated using a ZnO/SiO2/Si monolithic convolver. Stored signals in the form of the charge grating in the SiO2/Si interface is duplicated in the second storage centers in the ZnO by injecting electrons from the metal electrode. A storage time of more than 10 h has been obtained.