OTS PHASE CHANGE RANDOM ACCESS MEMORY ELEMENT FOR IMPROVING VT DRIFT FROM OVONIC THRESHOLD SWITCH AND REFERENCE DETERMINING METHOD OF THE SAME

摘要

Disclosed are a phase change memory device for improving voltage drift generated in OTS, and a method of determining a sensing reference value of the phase change memory device. According to an embodiment, the phase change memory device includes: a plurality of bit lines; A plurality of source lines disposed to cross the plurality of bit lines; A plurality of memory cells disposed at intersections of the plurality of bit lines and the plurality of source lines, each configured to include a phase change layer and an OTS; A mapping circuit for determining and storing a sensing reference value used in a process of performing a read operation on the plurality of memory cells; A sensing circuit configured to output a resistance value of the at least one memory cell when a read operation is performed on at least one of the plurality of memory cells; And a control unit updating the sensing reference value based on a resistance distribution according to a resistance value output from the sensing circuit.