A Novel Body Effect Reduction Technique to Recessed Channel Transistor Featuring Partially Insulating Layer Under Source and Drain : Application to Sub-50nm DRAM Cell

We have successfully fabricated fully integrated advanced RCAT (Recess Channel Array Transistor) featuring partially insulating oxide layers in bulk Si substrate, named Partially-insulated-RCAT (Pi-RCAT) to suppress body effect of conventional RCAT and improve current drivability in DRAM cell. The Pi-RCAT demonstrated superior characteristics in body effect, subthreshold slope (SW) and higher current drivability with comparable I
on
-I
off
characteristics in comparison with conventional RCAT. Furthermore, in the Partially-insulated-STI (Pi-STI) of core and peripheral structure formed simultaneously, well isolation characteristic is improved remarkably due to increase of effective isolation path. In this paper, Pi-RCAT is proved to be effective for the scalability and drivability of RCAT, and Pi-STI is suitable for the improvement of chip shrinkage efficiency.