TY - JOUR
T1 - Negative Capacitance in Short-Channel FinFETs Externally Connected to an Epitaxial Ferroelectric Capacitor
JF - IEEE Electron Device Letters
Y1 - 2016/01//
SP - 111
EP - 114
A1 - Asif I. Khan
A1 - Korok Chatterjee
A1 - Juan Pablo Duarte
A1 - Zhongyuan Lu
A1 - Angada Sachid
A1 - Sourabh Khandelwal
A1 - Ramamoorthy Ramesh
A1 - Chenming C. Hu
A1 - Sayeef Salahuddin
KW - Capacitance
KW - Capacitors
KW - Epitaxial growth
KW - FinFETs
KW - hysteresis
KW - Integrated circuit modeling
KW - Logic gates
AB - We 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.
VL - 37
ER -
TY - JOUR
T1 - Negative Capacitance in a Ferroelectric Capacitor
JF - Nature Materials
Y1 - 2014/12//
SP - 182
EP - 186
A1 - Asif I. Khan
A1 - Korok Chatterjee
A1 - Brian Wang
A1 - Steven Drapcho
A1 - Long You
A1 - Claudy R. Serrao
A1 - Saidur R. Bakaul
A1 - Ramamoorthy Ramesh
A1 - Sayeef Salahuddin
KW - Electrical and electronic engineering
KW - Electronic devices
KW - Ferroelectrics and multiferroics
AB - The 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.
VL - 14
IS - 2
JO - Nat Mater
ER -