Dual-workfunction gate engineering in a corner parasitics-free shallow-trench-isolation complementary-metal-oxide-semiconductor technology

In this work, through-the-gate implantation (TGI) of channel- and well-dopi ng is favorably combined with n(+)/p(+) gate implantation. This approach of fers an additional degree of freedom to optimize dual-workfunction gales in dependently from the fabrication of ultra-shallow source/drain junctions. B y using the same masks for each device type. no increase in process complex ity occurs. In combination with the extended trench isolation gate technolo gy (EXTIGATE) process architecture, a center parasitics-free shallow trench isolation (STI) is provided together with the separation of pre-implanted n(+)/p(+) polySi areas to inhibit lateral n(+)/p(+) cross-diffusion during gate activation. Nitrogen co-implantation into the gate is implemented to s uppress boron penetration and to provide relief from residual impurity cros s-diffusion within the gate during SID anneals. Besides high drive currents , excellent short channel-behavior and improved narrow width characteristic s are obtained with TGI-CMOS.