Dopant-free complementary metal oxide silicon field effect transistors

We present a dopant-free CMOS technology where n- and p-type semiconductor contacts are realized exclusively based on ultrathin silicon nitrides and metals with appropriate work function. Ellipsometry and FTIR measurements are applied to characterize the thermally grown nitride layers. Unipolar behavior and ohmic contact behavior are accomplished showing that with an appropriate nitride thickness dangling bonds as well as metal-induced gap states can be suppressed, thus yielding a depinning of the Fermi level. n-type and - for the first time - p-type MOSFETs using low-and high-work-function metals such as aluminum, nickel, or platinum are successfully presented. In contrast to (metal-silicon) Schottky-barrier MOSFETs, the fabricated devices exhibit on/off ratios larger than 10(6). (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim