Bulk fin-type field-effect transistor-based capacitorless dynamic random-access memory with strong resistance to geometrical variations

In this study, a bulk fin-type FET (FinFET)-based capacitorless one-transistor dynamic random-access memory (1T-DRAM) was proposed. The fabrication process of the proposed 1T-DRAM was similar to that of a typical junctionless bulk FinFETs, except that the p-type doped body fin region operated as a charge storage region. The effects of the geometrical variations, such as the fin angle (θ _fin) variation and line edge roughness (LER), which are inevitable in fabrication, on the transfer characteristics and memory performance of the proposed 1T-DRAM were studied. θ _fin was varied from 90° to 80°, and 200 samples with the LER were analyzed. Results revealed that the transfer characteristics and memory performance were affected by geometrical variations. However, the proposed 1T-DRAM exhibited an excellent retention time in all cases because the charge storage region was separated from the region of operation.