01754nas a2200349 4500008004100000022001300041245007900054210006900133260003900202490000800241520071500249653001600964653003100980653002501011653002001036653002801056653002101084653002501105653002301130100001501153700001701168700001901185700001101204700001101215700001501226700001401241700001701255700001101272700002401283700001901307856007801326 2017 eng d a0003695100aDifferential voltage amplification from ferroelectric negative capacitance0 aDifferential voltage amplification from ferroelectric negative c bAmerican Institute of Physics Inc.0 v1113 aWe demonstrate that a ferroelectric can cause a differential amplification without needing such an external energy source. As the ferroelectric switches from one polarization state to the other, a transfer of energy takes place from the ferroelectric to the dielectric, determined by the ratio of their capacitances, which, in turn, leads to the differential amplification. This amplification is very different in nature from conventional inductor-capacitor based circuits where an oscillatory amplification can be observed. The demonstration of differential voltage amplification from completely passive capacitor elements only has fundamental ramifications for next generation electronics. © 2017 Author(s).10aCapacitance10aDifferential amplification10aDifferential voltage10aEnergy transfer10aExternal energy sources10aferroelectricity10anegative capacitance10aPolarization state1 aKhan, A.I.1 aHoffmann, M.1 aChatterjee, K.1 aLu, Z.1 aXu, R.1 aSerrao, C.1 aSmith, S.1 aMartin, L.W.1 aHu, C.1 aRamesh, Ramamoorthy1 aSalahuddin, S. uhttps://rameshlab.lbl.gov/publications/differential-voltage-amplification02206nas a2200457 4500008004100000022001300041245011100054210006900165260005900234300001200293490000700305520079900312653001601111653001501127653001801142653002801160653002901188653002601217653002801243653002101271653002401292653001901316653001401335653002501349653002401374653002801398653003201426653001001458653002101468653002901489100001501518700001901533700001701552700001101569700001501580700001901595700002401614700001101638700001901649856008001668 2016 eng d a0741310600aNegative Capacitance in Short-Channel FinFETs Externally Connected to an Epitaxial Ferroelectric Capacitor0 aNegative Capacitance in ShortChannel FinFETs Externally Connecte bInstitute of Electrical and Electronics Engineers Inc. a111-1140 v373 aWe report subthreshold swings as low as 8.5 mV/decade over as high as eight orders of magnitude of drain current in short-channel negative capacitance FinFETs (NC-FinFETs) with gate length Lg=100 nm. NC-FinFETs are constructed by connecting a high-quality epitaxial bismuth ferrite (BiFeO3) ferroelectric capacitor to the gate terminal of both n-type and p-type FinFETs. We show that a self-consistent simulation scheme based on Berkeley SPICE Insulated-Gate-FET Model:Common Multi Gate model and Landau-Devonshire formalism could quantitatively match the experimental NC-FinFET transfer characteristics. This also allows a general procedure to extract the effective S-shaped ferroelectric charge-voltage characteristics that provides important insights into the device operation. © 2015 IEEE.10aCapacitance10aCapacitors10aDrain current10aEpitaxial ferroelectric10aFerroelectric capacitors10aFerroelectric devices10aFerroelectric materials10aferroelectricity10aintegrated circuits10aMOSFET devices10aNC-FinFET10anegative capacitance10aOrders of magnitude10aReconfigurable hardware10aSelf-consistent simulations10aSPICE10asub-60 mV/decade10aTransfer characteristics1 aKhan, A.I.1 aChatterjee, K.1 aDuarte, J.P.1 aLu, Z.1 aSachid, A.1 aKhandelwal, S.1 aRamesh, Ramamoorthy1 aHu, C.1 aSalahuddin, S. uhttps://rameshlab.lbl.gov/publications/negative-capacitance-short-channel-002207nas a2200433 4500008004100000022001300041245005400054210005400108260002800162300001200190490000700202520095300209653002701162653002301189653001601212653001501228653002301243653002301266653003401289653002901323653002601352653002401378653002801402653002101430653002501451653002101476653002501497653002101522100001501543700001901558700001301577700001601590700001201606700001501618700001701633700002401650700001901674856008001693 2015 eng d a1476112200aNegative capacitance in a ferroelectric capacitor0 aNegative capacitance in a ferroelectric capacitor bNature Publishing Group a182-1860 v143 aThe Boltzmann distribution of electrons poses a fundamental barrier to lowering energy dissipation in conventional electronics, often termed as Boltzmann Tyranny. Negative capacitance in ferroelectric materials, which stems from the stored energy of a phase transition, could provide a solution, but a direct measurement of negative capacitance has so far been elusive. Here, we report the observation of negative capacitance in a thin, epitaxial ferroelectric film. When a voltage pulse is applied, the voltage across the ferroelectric capacitor is found to be decreasing with time - in exactly the opposite direction to which voltage for a regular capacitor should change. Analysis of this inductance -like behaviour from a capacitor presents an unprecedented insight into the intrinsic energy profile of the ferroelectric material and could pave the way for completely new applications. © 2015 Macmillan Publishers Limited. All rights reserved.10aBoltzmann distribution10aBoltzmann equation10aCapacitance10aCapacitors10aDirect measurement10aEnergy dissipation10aEpitaxial ferroelectric films10aFerroelectric capacitors10aFerroelectric devices10aFerroelectric films10aFerroelectric materials10aferroelectricity10aFundamental barriers10aIntrinsic energy10anegative capacitance10aNew applications1 aKhan, A.I.1 aChatterjee, K.1 aWang, B.1 aDrapcho, S.1 aYou, L.1 aSerrao, C.1 aBakaul, S.R.1 aRamesh, Ramamoorthy1 aSalahuddin, S. uhttps://rameshlab.lbl.gov/publications/negative-capacitance-ferroelectric-002066nas a2200373 4500008004100000020001800041245007600059210006900135260005900204520086500263653001601128653001501144653002201159653002301181653002901204653002601233653002801259653002101287653000901308653002501317653001401342653003801356653002601394653002301420653003301443653001301476653002301489653002501512100001501537700001901552700002401571700001901595856007801614 2015 eng d a978146738568800aUnderstanding negative capacitance dynamics in ferroelectric capacitors0 aUnderstanding negative capacitance dynamics in ferroelectric cap bInstitute of Electrical and Electronics Engineers Inc.3 aWe investigate negative capacitance transients-the time period during ferroelectric switching when the voltage across a ferroelectric changes in a direction opposite to that of the charge-by constructing a simple series network of an isolated single crystalline ferroelectric capacitor and an external resistor. A study of negative capacitance dynamics in such a circuit reveals that the time scale of this phenomenon is controlled by the external resistor rather than by the material dependent intrinsic speeds. As a canonical approach for directly measuring ferroelectric negative capacitance, these experiments could guide the efforts to stabilize negative capacitance in a transistor structure for sub-60 mV/decade subthreshold characteristics as well as help assess negative capacitance response speed at technologically relevant dimensions. © 2015 IEEE.10aCapacitance10aCapacitors10aenergy efficiency10aExternal resistors10aFerroelectric capacitors10aFerroelectric devices10aFerroelectric switching10aferroelectricity10airon10anegative capacitance10aResistors10aSemiconductor device measurements10aSemiconductor devices10aSingle-crystalline10aSubthreshold characteristics10aSwitches10aTransient analysis10aTransistor structure1 aKhan, A.I.1 aChatterjee, K.1 aRamesh, Ramamoorthy1 aSalahuddin, S. uhttps://rameshlab.lbl.gov/publications/understanding-negative-capacitance