A novel 0.79 /spl mu/m/sup 2/ SRAM cell by KrF lithography and high performance 90 nm CMOS technology for ultra high speed SRAM

The smallest SRAM cell, 0.79 /spl mu/m/sup 2/, was realized by a revolutionary cell layout, fine tuned OPC technique to overcome the 248 nm KrF lithography limitation, instead of using 193 nm ArF lithography. Sub-100 nm CMOS technology was indispensable to achieve the cell size as well as the performance. The high performance transistors were made with 80 nm gate length including 15 /spl Aring/ nitrided gate oxide layer, indium channel and halo implantation processes. The novel cell exhibits excellent neutron SER immunity, compared with ones of the SRAM cell by previous generation technologies.