Fully integrated and functioned 44nm DRAM technology for 1GB DRAM

44 nm feature sized 8F
²
1Gb DRAM is fully integrated and functioned for the first time with the smallest cell size of 0.015 um
²
. A novel cell-transistor structure and new DRAM process technologies are developed. In order to control the threshold voltage uniformity and body-bias sensitivity of saddle-fin cell-transistor, the channel doping profile and saddle-fin geometric dependency were analytically expressed with experimental data. The weak fin height dependency on cell-V
_T
diminishes the burden of the saddle-fin patterning processes. And the low body-bias sensitivity of the saddle-fin cell-transistor leads wide tWR (write recovery time) margins. Cylinder-like MIM cell capacitor with ZAZ dielectric is exploited on cell capacitor. Copper implemented triple-metal layer and WN barrier-metal techniques were developed to decrease chip size.