Ferroelectric tunnel fet switch and memory
AssigneeEcole Polytechnique Federale De Lausanne (Epfl)
InventorMihai Adrian IONESCU
Life of this patent
Estimating the term…
Abstract
A Ferroelectric tunnel FET switch as ultra-steep (abrupt) switch with subthreshold swing better than the MOSFET limit of 60 mV/decade at room temperature combining two key principles: ferroelectric gate stack and band-to-band tunneling in gated p-i-n junction, wherein the ferroelectric material included in the gate stack creates, due to dipole polarization with increasing gate voltage, a positive feedback in the capacitive coupling that controls the band-to-band (BTB) tunneling at the source junction of a silicon p-i-n reversed bias structure, wherein the combined effect of BTB tunneling and ferroelectric negative capacitance offers more abrupt off-on and on-off transitions in the present proposed Ferroelectric tunnel FET than for any reported tunnel FET or any reported ferroelectric FET.
Claims12
A ferroelectric tunnel FET comprising a ferroelectric gate stack and a band-to-band tunneling in gated p-i-n junction, wherein the ferroelectric material included in the gate stack creates, due to dipole polarization with increasing gate voltage, a positive feedback in the capacitive coupling that controls the band-to-band (BTB) tunneling at the source junction of a silicon p-i-n reversed bias structure, such that the combined effect of band-to-band tunneling and ferroelectric negative capacitance offers more abrupt off-on and on-off transitions than for any reported tunnel FET or any reported ferroelectric FET.
A ferroelectric Tunnel FET one transistor (1T) memory based on the hysteretic behavior generated by ferroelectric material, the ultra-low Ioff offered by the reversed biased silicon p-i-n junction and the abrupt off-on and on-off transitions.
A unipolar or ambipolar ferroelectric carbon nanotube tunnel FET comprising a carbon nanotube tunneling device with ferroelectric gate stack and band-to-band tunneling mechanism.
A semiconductor device based on a gated junction or field effect transistor effect that combines very steep switching the band-to-band tunneling and the positive feedback or negative capacitance associated with a ferroelectric gate stack.
Dependencies are inferred from the claim text.