LONDON – An Intel-led team will reveal a tri-gate FinFET-type quantum-well InGaAs MOSFET at the upcoming International Electron Devices Meeting being held Washington D.C. December 5 to 7.
The full IEDM program has yet to be revealed but a paper set to be given by Marko Radosavljevic has been tipped by the organizers as one of the highlights of the conference. The authorship team will include Welsh wafer supplier IQE plc (Cardiff, Wales). The full program is due to be published towards the end of September.
Intel (Santa Clara, Calif.) has caused a stir the semiconductor industry with the introduction of its tri-gate, or FinFET, technology as part of its 22-nm CMOS silicon manufacturing process technology offering. Intel is the first company to do so with others, such as TSMC and Samsung looking to do so at 14-nm.
At IEDM Intel plans to show the way again with a compound semiconductor version that promises faster transistors than silicon. Intel technical executives have in the past tipped InGaAs, possibly embedded on silicon for ease of manufacturing and to carry non-critical circuitry as a way forward for the semiconductor industry. Intel Fellow Paolo Gargini has proposed the integration of an InGaAs quantum-well FET with a high-K dielectric gate stack. (see Intel's Gargini pushes III-V-on-silicon as 2015 transistor option).
Radosavljevic's IEDM presentation on InGaAs FinFET devices with improved electrostatic performance, due to the fin shape, looks set to be in-line with that proposal.
However, until now, though, the best performing III-V MOSFETs have been planar types, scaled to 10-nm gate lengths and with ultra-thin-bodies. Two key metrics are sub-threshold slope (the steeper it is, the more abruptly the device can switch) and drain-induced barrier lowering, or DIBL (the smaller it is, the less sensitive the device is to drain voltage and the more efficiently it can turn off).
Long-channel devices exhibited a subthreshold slope of 66 mV/decade, close to the theoretical minimum of 60 mV/decade, while DIBL of short gate length devices was significantly improved over best-in-class planar III-V MOS devices. The better electrostatics of these devices comes from their narrow fin width and high-quality high-k gate dielectric.
The image above is a cross-sectional scanning electron micrograph of the 3-D tri-gate InGaAs device structures perpendicular to the fin direction, after fin and gate recess etches and before high-k/metal gate deposition, with a 30-nm fin-width and 50-nm height.
The Intel paper is number 33.1 Electrostatics Improvements in 3-D Tri-Gate Over Ultra-Thin Body Planar InGaAs Quantum Well Field Effect Transistors with High-K Gate Dielectric and Scaled Gate-to-Drain/Gate-to-Source Separation, M. Radosavljevic et al, Intel/IQE.
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