Carbon-paste nanocomposites as unconventional gate electrodes for electrolyte-gated organic field-effect transistors: electrical modulation and bio-sensing

Nanocomposite carbon-paste electrodes (NC-CPEs) have been investigated for the first time in electrolytegated organic field-e¿ect transistors (EGOFETs) as a replacement of conventional metal gate electrodes, using carbon nanotubes (CNTs) as a model carbon filler. Interestingly, the electrical properties of the resulting devices have been modulated by changing the loading percentage of CNTs within the insulating polymeric matrix. The potential of using such non-conventional gate electrodes for sensing purposes has also been evaluated by investigating, as a proof of concept, the formation of a supramolecular complex between a functionalized CNT-based NC-CPE containing ß-cyclodextrin (ß-CD) as a bio-recognition element and tryptophan (TRP). This approach, in synergism with the amplification function of an EGOFET, a¿ords a shift in the threshold voltage (VTH) of the transistor, giving promising analytical results with detection limits at picomolar levels (1.0 ± 0.1 pM) as well as a linear response from 10-12 to 10-9 M. Accordingly, NC-CPEs have been demonstrated to be a potential alternative to metal gate electrodes for the development of a new generation of highly sensitive carbon-based EGOFET bio-sensorsPostprint (published version

A New 6 Metal Gate PMOS Process

This paper presents the development, fabrication, and testing of a new 6” Metal Gate PMOS process. The new 6-inch Metal Gate PMOS process is an upgrade from the 4-inch Metal Gate PMOS process, which is the process currently used at RIT for the IC Technology course as ivell as the Short Course. The upgrades include the use of 6-inch wafers from 4-inch wafers, four levels per mask lithography instead of one level per mask lithography, ion implant instead of spin on dopant, and the number of control wafers was reduced from five wafers to three wafers. Development and fabrication of the 6-inch Metal Gate PMOS process are discussed, as well as the testing of the devices on the chip. The overall process was determined to be successful, yielding working devices, and is suitable to be used in the future with the IC Technology course and the Short Course

Polysilicon vs. Aluminum Gate PMOS Ring Oscillators

A nine stage PMOS ring oscillator was designed using polysilicon gates for a self-aligning process while another was designed using a standard metal gate process. A comparison of the polysilicon and metal gate PMQS processes was planned to show the reduced gate capacitance of the self-aligning process. This reduced gate capacitance was to be observed by measuring and comparing the propagation delay of each design on the oscilloscope

Electron lithography STAR design guidelines. Part 1: The STAR user design manual

The STAR system developed by NASA enables any user with a logic diagram to design a semicustom digital MOS integrated circuit. The system is comprised of a library of standard logic cells and computer programs to place, route, and display designs implemented with cells from the library. Library cells of the CMOS metal gate and CMOS silicon gate technologies were simulated using SPICE, and the results are shown and compared

An electret-based pressure sensitive MOS transistor

The operation of the MOSFET is based on the fact that the lateral conductivity of silicon at the silicon-dioxide-silicon interface strongly depends on the transverse electric field in the oxide. Adding a small air-filled spacer between the metal gate and the oxide, and applying a voltage across the insulator on top of the silicon, the lateral conductivity can become pressure sensitive. The generation of the electric field in the insulator can also be provided by means of an electret. The theory, realization, and performance of an integrated electret-MOSFET-based pressure sensor are presente

A device-level characterization approach to quantify the impacts of different random variation sources in FinFET technology

A simple device-level characterization approach to quantitatively evaluate the impacts of different random variation sources in FinFETs is proposed. The impacts of random dopant fluctuation are negligible for FinFETs with lightly doped channel, leaving metal gate granularity and line-edge roughness as the two major random variation sources. The variations of Vth induced by these two major categories are theoretically decomposed based on the distinction in physical mechanisms and their influences on different electrical characteristics. The effectiveness of the proposed method is confirmed through both TCAD simulations and experimental results. This letter can provide helpful guidelines for variation-aware technology development

Statistical variability and reliability in nanoscale FinFETs

A comprehensive full-scale 3D simulation study of statistical variability and reliability in emerging, scaled FinFETs on SOI substrate with gate-lengths of 20nm, 14nm and 10nm and low channel doping is presented. Excellent electrostatic integrity and resulting tolerance to low channel doping are perceived as the main FinFET advantages, resulting in a dramatic reduction of statistical variability due to random discrete dopants (RDD). It is found that line edge roughness (LER), metal gate granularity (MGG) and interface trapped charges (ITC) dominate the parameter fluctuations with different distribution features, while RDD may result in relatively rare but significant changes in the device characteristics

Evidence for multiple impurity bands in sodium-doped silicon MOSFETs

We report measurements of the temperature-dependent conductivity in a silicon metal-oxide-semiconductor field-effect transistor that contains sodium impurities in the oxide layer. We explain the variation of conductivity in terms of Coulomb interactions that are partially screened by the proximity of the metal gate. The study of the conductivity exponential prefactor and the localization length as a function of gate voltage have allowed us to determine the electronic density of states and has provided arguments for the presence of two distinct bands and a soft gap at low temperature.Comment: 4 pages; 5 figures; Published in PRB Rapid-Communication