Switching device having bi-directional drive characteristics and method of operating same

A phase-change memory device comprising:

• a first electrode;
• a second electrode;
• a P-type phase-change layer interposed between the first electrode and the second electrode, the P-type phase-change layer being used as a data storage as a crystal state changes due to a voltage applied through the first electrode and the second electrode;
• and
• an N-type semiconductor layer arranged on the P-type phase-change layer,
• wherein the P-type phase-change layer and the N-type semiconductor layer form a PN diode, and
• the P-type phase-change layer forms a Schottky diode at a contact interface with the second electrode.

A phase-change memory device comprising:

• a first electrode;
• a second electrode;
• and
• a phase-change memory cell interposed between the first electrode and the second electrode,
• wherein the phase-change memory cell comprises:
• a first N-type semiconductor material layer;
• a second N-type semiconductor material layer;
• a P-type intermediate layer between the first and second N-type semiconductor material layers and used as data storage as a crystal state changes due to a voltage applied through the first electrode and the second electrode;
• a first tunneling thin film arranged between the first N-type semiconductor material layer and the P-type intermediate layer, the first tunneling thin film configured to reduce a leakage current in the intermediate layer or prevent intermixing between a N-type dopant present in the first N-type semiconductor material layer and a P-type dopant present in the P-type intermediate layer.