World's first monolithic 3D-FPGA with TFT SRAM over 90nm 9 layer Cu CMOS

World's first monolithically integrated Thin-Film-Transistor (TFT) SRAM configuration circuits over 90nm 9 layers of Cu interconnect CMOS is successfully fabricated at 300mm LSI mass production line for 3-dimensional Field Programmable Gate Arrays (3D-FPGA). This novel technology built over the 9
^th
layer of Cu metal features aggressively scaled amorphous Si TFT having 180nm transistor gate length, 20nm gate oxide, fully silicided gate, S/D, all below 400C processing essential to not impact underlying Cu interconnects. Low temperature TFT devices show excellent NTFT/PTFT transistor I
_on
/I
_off
ratios over 2000/100 respectively, operate at 3.3V, E-field scalable, and are stable for SRAM configuration circuits. We believe this 3D-TFT technology is a major breakthrough innovation to overcome the conventional CMOS device shrinking limitation.