Investigations of Photovoltaic Ferroelectric-Semiconductor Nonvolatile Memory

The feasibility of a new kind of nonvolatile digital memory is proposed and examined. The basis of the memory is an anomalous photovoltaic phenomenon found in ferroelectric ceramics--a photovoltage with a polarity that depends on the direction of the remanent polarization. Described are proposed memory cell structures that function in matrix arrangements as nonvolatile read/write random access memory or electrically alterable programmable read-only memory. Test results obtained with an experimental test unit also are described. Included is a survey of methods for producing ferroelectric films. (Author)