Novel Lithography-Independent Pore Phase Change Memory

We have successfully demonstrated a novel "pore" phase change memory cell, whose critical dimension (CD) is independent of lithography. Instead, the pore diameter is accurately defined by intentionally creating a "keyhole" with conformal deposition. Fully integrated 256 kbit test chips have been fabricated in 180nm CMOS technology. We report SET times of 80ns, RESET currents less than 250μA, and accurate sub-lithographic CDs that can be less than 20% the size of the lithographically -defined diameter.