Transistors are the switches or gates for electronic signals. The smaller these are, the smaller the electronic devices can be. Innovations have led to the ability to miniaturize electronic devices to the smallest scale – individual molecules. Understandably, this building process has proven to be challenging. Improved gating strategies, increased knowledge on structure and control, and the ability to operate at room temperature are critical factors in determining the full potential of molecular electronic devices.
This innovation describes the design of a molecular transistor capable of measuring electroconductivity on an electrostatically regulated atomic scale. The design considers a building process amenable to manufacturing and a variety of operating environments.
This technology is available for licensing or for further development through a collaborative research agreement with the National Research Council of Canada (NRC). The business opportunity may be referred to by its NRC ID: 2004-094.
Areas of application include memory storage devices, logic functions, and chemical sensing applications at the molecular scale.
How it works
An atomic scale transistor is created with a perturbing species having a localized electronic charge, and a sensing species having a changeable electronic conductivity. At least one of the perturbing species and sensing species are in the form of a single atom or a single molecule. The perturbing species can be a silicon dangling bond from a substrate atom that has a charge state that can add or withdraw a charge at the scale of one electron. Varying the substrate voltage modifies the charge state of the substrate atom at one electron unity of charge. When a grounded electrical contact and a sensing species with electronic conductivity are placed in proximity to the dangling bond, the dangling bond functions as a single atom gate electrode. If the dangling bond is placed in an array of sensing species, it results in the creation of a multi-channel gate transistor at the atomic-size level.
Currently, a large obstacle in microelectronics is the formation of high-density integrated circuits. By fabricating transistors with molecules and atoms, improved densities can be achieved. The formation of molecular electronic circuits can also be achieved through a self-assembly process, eliminating some constraints in lithographic processes. Because a single atom with a varying charge state can act as a gate, smaller structures are possible with reduced gate sizes and leakage. This implementation is also compatible with current silicon technology, enabling hybrid molecular-silicon devices. These devices can take advantage of the properties of various molecule types to enable specific or general functionality.
NRC file 2004-094-08:
- United States Divisional Patent No. 8,278,654 – Electrostatically regulated atomic scale electroconductivity device
NRC file 2004-094-03:
European patent office: EP 1856741 A1 - Electrostatically regulated atomic scale electroconductivity device
Patent issued in Canada and USA.