Overview of the Technology
Over the last decade, nanoelectronic devices have been fabricated using a variety of material systems. At Qusemde, our R&D work on nanoelectronic devices is focused primarily on devices that can be formed from gates on a silicon nanowire. The key nanoelectronic device is the single electron transistor (SET). The SET is based on the Coulomb Blockade of tunneling in an ultrasmall capacitor. In the early days, the primary applications of the SET were on high end instruments especially for use in scientific applications. The applications include supersensitive electrometer, dc current standards, charge state logics, single-electron spectroscopy, and sensitive thermometry. Recently with the advance of standard CMOS technology into the tens of nanometer regime, it appears that it should be able to make devices that can operate at reasonable temperatures and hence expand the range of instruments and applications. Here, we outline the components of the technology: a) the devices of interest; b) the physical structures in silicon that are compatible with the basic physics; c) the fabrication technology; and d) software for simulation.
Devices
- single electron transistor
- single electron tunnelling diode
Nanowires in silicon
- Silicon nanowires have been fabricated, by other teams, using a combination of e-beam and other technologies.
Fabrication Technology
- Qusemde has developed a propriety process for the fabrication of SETs in a commercial CMOS foundry
- Silicon on Insulator (SOI) 45nm, 32nm, and 28nm.
Software
- The need for software that enables the simulation of single electron transistors and other nonstandard devices is growing as designers begin to utilize those devices. The present circuit simulation software tools are based on models for the mosfet and it has always been difficult to include nonstandard devices. Now, based partly on our experience in designing, Qusemde is developing software that can be incorporated into the standard simulation software.