[paper] Logic Without CMOS

Jonathan Hall and Manus Hayne

Logic Without CMOS: A III-V Semiconductor, Single Charge Carrier Approach to Digital Logic

WOCSDICE-EXMATEC 2023, Palermo (Italy), 21-25 May 2023

Department of Physics, Lancaster University, Lancaster, United Kingdom

Abstract: A new patent-pending approach to digital logic devices is proposed as an alternative to complimentary metal-oxide-semiconductor (CMOS) logic. A novel III-V semiconductor digital logic device combines both the “n” and “p” equivalents of CMOS into a single heterostructure device using just one type of charge carrier. The device, which forms an inverter, consists of two charge-accepting channel layers which sandwich a central electron (or hole) reservoir. Under zero bias the charge remains in the reservoir with both channel layers absent of free charge carriers (off state). Once a bias is applied to the gate, charge is either pushed into the bottom channel (negative bias) or pulled into the top channel (positive bias) turning one channel on whilst the other remains off. Thus, the complementary behaviour of logic, in which one part of the logic element is on and the other is off, is achieved without the asymmetry of hole and electron mobility. Proof of concept devices have been designed in both the well documented GaAs/AlxGa1-xAs system and in the 6.1Å family of semiconductors. One-dimensional, room temperature energy-band simulations using nextnano++ (software for semiconductor devices) [1] have shown effective and symmetric logic function at low voltage and an excess of 1,000× charge density ratio between the two channels under operation. Proof of concept devices are currently undergoing fabrication.

Fig: Proposed device architecture for an inverter, utilising electrons as the charge carrier. The “N” and “P” charge-accepting layers represent the equivalent CMOS transistors. With positive VG, the electrons are pulled from the reservoir into the upper channel, and with negative VG, the electrons are pushed into the lower channel. With zero bias, the charge remains within the reservoir and the channels are resistive (off). The barrier layers can consist of grown semiconductor or deposited dielectric.

Acknowledgments: Thanks to the Leverhulme Trust for a PhD studentship for Jonathan Hall and to nextnano for access to their software.

[paper] Compact Model for Electrostatics of III–V GAA Transistors

Mohit D. Ganeriwala, Francisco G. Ruiz*, Enrique G. Marin* and Nihar R. Mohapatra

A unified compact model for electrostatics of III–V GAA transistors with different geometries

Journal of Computational Electronics (2021)

Published: 07 August 2021

DOI: 10.1007/s10825-021-01751-2

 
Department of Electrical Engineering, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat, 382355, India
*Department of Electronics, University of Granada, Granada, Spain

Abstract: In this work, a physics-based unified compact model for III-V GAA FET electrostatics is proposed. The model considers arbitrary cross-sectional geometry of GAA FETs viz. rectangular, circular and elliptical. A comprehensive model for cuboid GAA FETs is developed first using the constant charge density approximation. The model is then combined with the earlier developed model for cylindrical GAA FETs to have a unified representation. The efficacy of the model is validated by comparing it with simulation data from a 2D coupled Poisson-Schrödinger solver. The proposed model is found to be accurate for GAA FETs with different geometries, dimensions and channel materials and computationally efficient.

Fig: III–V GAA transistors with different geometries

Acknowledgements: This work is supported by the Visvesvaraya PhD scheme by MeitY, Gover nment of India Enrique G. Marin gratefully acknowledges Juan de la Cierva Incorporation IJCI-2017-32297 (MINECO/AEI).

[PhD Thesis] III-V MOS-HEMTs for 100-340GHz Communications Systems

UNIVERSITY OF CALIFORNIA

Santa Barbara

III-V In_xGa_1-xAs / InP MOS-HEMTs for 100-340GHz Communications Systems

A dissertation for PhD degree in Electrical and Computer Engineering

by Brian David Markman

Abstract: This work summarizes the efforts made to extend the current gain cutoff frequency of InP based FET technologies beyond 1THz. Incorporation of a metal-oxide-semiconductor field effect transistor (MOSFET) at the intrinsic Gate Insulator-Channel interface of a standard high electron mobility transistor (HEMT) has enabled increased g_m,i by increasing the gate insulator capacitance density for a given gate current leakage density. Reduction of RS,TLM from 110 Ω.μm to 75Ω.μm and Ron(0) from 160Ω.μm to 120Ω.μm was achieved by removing/thinning the wide bandgap modulation doped link regions beneath the highly doped contact layers. Process repeatability was improved by developing a gate metal first process and D_it was improved by inclusion of a post-metal H₂ anneal. In_xGa_1-xAs / InAs composite quantum wells clad with both InP and In_xAl_1-xAs were developed for high charge density and low sheet resistance to minimize source resistance. 

Figure a) InP-based HEMT b) III-V DC optimized MOSFET c) proposed InP-based MOS-HEMT

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[Citation] Markman, B. D. (2020). III-V In_xGa_1-xAs / InP MOS-HEMTs for 100-340GHz Communications Systems. UC Santa Barbara. ProQuest ID: Markman_ucsb_0035D_14853. Merritt ID: ark:/13030/m5v4681j. Retrieved from https://escholarship.org/uc/item/6st812pb

[postponed]: EUROSOI-ULIS 2020

6th EUROSOI-ULIS

Caen, Normandy, France

The EUROSOI-ULIS organizers have announced that the conference 

and of the associated satellite events will be postponed to 

August 31st - September 4th

The sixth joint EUROSOI-ULIS conference will be hosted by Normandy University (ENSICAEN, UNICAEN, ESIGELEC) in Caen, inside the William the Conqueror Castel, in the auditorium of Museum of Fine Arts. The organizing committee invites scientists and engineers working on SOI technology and advanced nanoscale devices to actively participate by submitting high quality, original contributions (2-page abstracts).

The sixth joint EUROSOI-ULIS conference will be hosted by Normandy University (ENSICAEN, UNICAEN, ESIGELEC) in Caen, inside the William the Conqueror Castel, in the auditorium of Museum of Fine Arts. The organizing committee invites scientists and engineers working on SOI technology and advanced nanoscale devices to actively participate by submitting high quality, original contributions (2-page abstracts).

Important dates :

• abstract submission deadline : January 30, 2020
• notification of acceptance : February 3, 2020
• postponed confernce dates : August 31st - September 4th 2020

Papers in the following areas are solicited:
• Advanced SOI materials and structures: physical mechanisms and innovative SOI-like devices
• New channel materials for CMOS: strained Si, strained SOI, SiGe, GeOI, III-V and high mobility materials on insulator, carbon nanotubes, graphene and other two-dimensional materials
• Properties of ultra-thin films and buried oxides: defects, interface quality, thin gate dielectrics, high-κ materials for switches and memory.
• Nanometer scale devices: technology, characterization techniques and evaluation metrics for high performance, low power, reliability, high frequency and memory applications
• Alternative transistor architectures: FDSOI, Nanowire, FinFET, MuGFET, vertical MOSFET, FeFET and Tunnel FET, MEMS/NEMS, Beyond-CMOS nanoelectronic devices
• New functionalities in silicon-compatible nanostructures and innovative devices representing the More than Moore domain: nanoelectronic sensors, biosensor devices, energy harvesting devices, RF devices, imagers, etc.
• CMOS scaling perspectives: device/circuit level performance evaluation, switches and memory scaling; three-dimensional integration of devices and circuits, heterogeneous integration
• Transport phenomena: compact modeling, device simulation, front- and back-end process simulation
• Advanced test structures and characterization techniques: parameter extraction, reliability and variability assessment techniques for new materials and novel devices

Need help or information : eurosoiulis2020@sciencesconf.org
Conference Chair: Bogdan Cretu