On the role of Coulomb scattering in hafnium-silicate gated silicon n and p-channel metal-oxide-semiconductor-field-effect-transistors

• In this work, the impact of the local and remote Coulomb scattering mechanisms on electron and hole mobility are investigated. The effective mobilities in quasi-planar finFETs with TiN/Hf(0.4)Si(0.6)O/SiO(2) gate stacks have been measured at 300 K and 4 K. At 300 K, electron mobility is degraded below that of bulk MOSFETs in the literature, whereas hole mobility is comparable. The 4 K electron and hole mobilities have been modeled in terms of ionized impurity, local Coulomb, remote Coulomb and local roughness scattering. An existing model for remote Coulomb scattering from a polycrystalline silicon gate has been adapted to model remote Coulomb scattering from a high-kappa/SiO(2) gate stack. Subsequently, remote charge densities of 8 x 10(12) cm(-2) at the Hf(0.4)Si(0.6)O/SiO(2) interface were extracted and shown to be the dominant Coulomb scattering mechanism for both electron and hole mobilities at 4 K. Finally, a Monte Carlo simulation showed remote Coulomb scattering was responsible for the degraded 300 K electron mobility.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Publication and Content Type

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art (subject category)