Performance assessment of (110) p-FET high-κ/MG: is it mobility or series resistance limited?

In this article the impact of Si-substrate orientation on mobility performance is studied for p-MOSFET's with both HfSiON and SiON based dielectrics. Consistent with previous studies, the I"o"n at fixed I"o"f"f is 100% larger for Si(110) larger than for standard Si(100). A thorough analysis of the factors influencing I"o"n (EOT, mobility and R"s"e"r"i"e"s) for short channel devices (until L"m"e"t=80 nm) indicates that a 200% increase of the mobility at high V"g is the source of this performance enhancement. The lower I"o"n increase (only 100%) compared to what is expected from the mobility is only explained by a larger impact of the R"s"e"r"i"e"s (70% of the total resistance) for short channel devices. As a result additional room for I"o"n improvement can be reached by device and R"s"e"r"i"e"s optimization.