Technological characterization of a standard Closed cell for Molecular Field-Coupled Nanocomputing

Moore’s Law, which has long described the scaling evolution of electronic devices, is now approaching its limit, highlighting the constraints of CMOS technology under extreme miniaturization. The search for alternatives to silicon-based systems has therefore driven research toward new and more promising technologies, capable of complex computation with minimal size and power consumption. One of the most relevant beyond-CMOS approaches is Molecular Field-Coupled Nanocomputing (MolFCN). MolFCN encodes binary information by localizing charges within molecules organized on a substrate to form functional structures, such as wires. The initial MolFCN wire design, known as the trench device, features a core metallic layer hosting molecules deposited at the bottom of a dielectric trench, with two metal electrodes placed at the top of the trench walls. Information propagation in MolFCN occurs through electrostatic interactions between neighboring molecules, making the system current-less. This process relies on the activation and deactivation of the localized charge on molecules by means of the applied vertical electric field, flowing from the top electrodes to the bottom metal substrate. The field effectiveness depends not only on its strength, but also on the geometrical positioning of electrodes with respect to molecules. Simulations of the trench device revealed that the top electrodes have limited influence on the central regions of wider wires, where information propagation becomes unreliable. To overcome these limitations, a new Closed design was introduced, in which the upper part of the trench is completely filled with metal surrounded by dielectric, forming a single continuous top electrode. This work focuses first on the creation and simulation of the Closed structure using Sentaurus Structure Editor. A mono-electrode Closed wire is generated through automated scripts, which define key geometrical parameters—such as wire width, height, and length—and build the structure for subsequent electrical simulation in Sentaurus SDevice. This automation allows rapid simulations of multiple geometries, enabling the identification of structural limits and optimal operating conditions. Once the Closed device is simulated, it is compared with a structurally analogous trench device. The comparison focuses on the analysis of electric field distribution within the central wire regions. Both devices are simulated using Sentaurus and SCERPA (Self-Consistent ElectRostatic Potential Algorithm), a tool that iteratively solves electrostatic interactions between molecules to model information propagation. A range of wire widths is analyzed to assess propagation efficiency, showing the superior performance in terms of field driving capabilities of the Closed design, particularly for wider wires. Following this comparison, a three-electrode Closed wire is investigated, to study how the spacing between multiple top electrodes affects field distribution in the inter-electrode core regions. Various electrode distances are simulated to identify potential fabrication constraints that could compromise device operation. The analysis is supported by a MATLAB script linking SDevice output fields to SCERPA, automatically extracting the relevant data and generating pre-simulation structures. By examining information propagation across multiple configurations, the study identifies the maximum allowable inter-electrode spacing that ensures correct device operation, defining the geometrical limits of this technology.