A unified 7.5nm dash-type confined cell for high performance PRAM device

We present a new-type confine structure within 7.5 nm width dash-contact for sub 20 nm generation PRAMs. Phase change material (PCM) by chemical vapor deposition (CVD) was perfectly filled in a 7.5 nm width dash-contact without void along with 30 nm depth. By adopting confined CVD-PCM, we were able to reduce the reset current below ~160 muA and to obtain high reliability. In addition, the programming time of dash-confined cell was much improved to 50 ns due to volume confinement of PCM cell. Consequently, we firstly demonstrate the high performance of the 7.5 nm width confined cell, which is the smallest size close to physical limit.