Multi-terminal chalcogenide memory cells having multiple binary or
non-binary bit storage capacity and methods of programming same. The
memory cells include a pore region containing a chalcogenide material
along with three or more electrical terminals in electrical communication
therewith. The configuration of terminals delineates spatially distinct
regions of chalcogenide material that may be selectively and
independently programmed to provide multibit storage. The application of
an electrical signal (e.g. electrical current or voltage pulse) between a
pair of terminals effects a structural transformation in one of the
spatially distinct portions of chalcogenide material. Application of
electrical signals to different pairs of terminals within a chalcogenide
device effects structural transformations in different portions of the
chalcogenide material. The structural states produced by the structural
transformations may be used for storage of information values in a binary
or non-binary (e.g. multilevel) system. The selection of terminals
provides for the selective programming of specific and distinct portions
within a continuous volume of chalcogenide material, where each
selectively programmed portion provides for the storage of a single
binary or non-binary bit. In devices having three or more terminals, two
or more selectively programmable portions are present within the volume
of chalcogenide material occupying the pore region and multibit storage
is accordingly realized. The instant invention further includes methods
of programming chalcogenide memory cells having three or more terminals
directed at the storage of multiple bits of information in binary or
non-binary systems.