T1.5 Statistical characterization and modeling of Resistive Switching Devices
Global objective 1 and 6 subobjective 1.4 and 6.1 and 6.2
Description
Though related to the TDDB mechanism, the Resistive Switching (RS) phenomena will be treated in a separate task,
because there is a change of point of view: whereas in the previous tasks in this WP TDDB is treated as a reliability
problem (and as such it should be studied to be predicted and avoided), in this task it is treated as the physical
principle of a new category of emerging devices. This is because some materials, as high-k dielectrics, show two
interchangeable conductivity states (a High Resistive State, HRS, and Low Resistive State, LRS) after the formation
of a conductive filament (CF, the BD event itself), what is known as Resistive Switching (RS). This phenomenon is
the basis of ReRAMs, which simply consist of MIS or MIM structures whose dielectric shows the RS behavior.
However, the UAB and UPC groups have recently shown that RS can be also observed in MOSFETs, having
presented a new device concept, the memFET, which could be defined as a multifunction electrically reconfigurable
device. In this task, a multidomain characterization (nanoscale, because of the extremely localization of the CF in the
device area) and device level (where their properties could be exploited) of resistive switching devices (MIM, MIS
and memFETs) based on ultrathin high-k devices will be carried out, addressing in this way the physical origin of the
conductive filament and the variability of key parameters for the device performance. The dependences of this
performance with the operation conditions will be also studied. Different technological options will be compared at
both levels, on test structures provided by the UAB external partners and/or fabricated at the IMB-CNM. The aim is
the evaluation of the optimal characteristics of the materials in the devices and the complete characterization of the
devices performance. In particular, the addressed issues will be:
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Characterization of the RS phenomenon at the nanoscale with AFM related techniques. Evaluation of the
technological/physical factors that control the mechanism and its variability at the nanoscale. From the
information extracted at the nanoscale and using device simulation tools, their impact at device level will be
addressed.
Evaluation at device level of the variability of relevant RS parameters (set and reset voltages, HRS and LRS
currents, switching times, power consumption, endurance…). Specific experimental set-ups (as those already
developed by the UAB group) will be used for the measurements of some of the parameters. Empirical laws for
their time, voltage and temperature dependences will be determined. Key parameters for the development of
reconfigurable computing architectures (T4.4) will be evaluated.
Schedule:
M1-M36
People involved: UAB:
UPC:
Rosana, Porti
Rubio
Inputs
D441 Simulation results of basic structures. Input to T1.5 (M24)
Expected Deliverables:
Deliverables
D151: Improved understanding of the RS mechanism and variability of the CF properties (M36)
D152: Laws for the operation dependence of relevant design-parameters of RS devices. Input to T4.4 (M12)
D153: Statistical models for RS devices. Input to T4.4 (M24)
D154: Optimized models of RS devices for best option architecture. Input to T4.4 (M32)