[paper] Coplanar OTFT

Blurred Electrode for Low Contact Resistance in Coplanar Organic Transistors

Xiaolin Ye, Xiaoli Zhao, Shuya Wang, Zhan Wei, Guangshuang Lv, Yahan Yang, Yanhong Tong, Qingxin Tang, and Yichun Liu

American Chemical Society; Nano; Dec.18, 2020

DOI: 10.1021/acsnano.0c08122

*Center for Advanced Optoelectronic Functional Materials Research, and Key Lab of UV-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China

Abstract: Inefficient charge injection and transport across the electrode/semiconductor contact edge severely limits the device performance of coplanar organic thin-film transistors (OTFTs). To date, various approaches have been implemented to address the adverse contact problems of coplanar OTFTs. However, these approaches mainly focused on reducing the injection resistance and failed to effectively lower the access resistance. Here, we demonstrate a facile strategy by utilizing the blurring effect during the deposition of metal electrodes, to significantly reduce the access resistance. We find that the transition region formed by the blurring behavior can continuously tune the molecular packing and thin-film growth of organic semiconductors across the contact edge, as well as provide continuously distributed gap states for carrier tunnelling. Based on this versatile strategy, the fabricated dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (DNTT) coplanar OTFT shows a high field-effect mobility of 6.08 cm2 V–1 s–1 and a low contact resistance of 2.32 kΩ cm, comparable to the staggered OTFTs fabricated simultaneously. Our work addresses the crucial impediments for further reducing the contact resistance in coplanar OTFTs, which represents a significant step of contact injection engineering in organic devices.

Fig: Coplanar Organic Transistors (oTFTs)

[Highlights] 2020 IEEE IEDM

The IEEE International Electron Devices Meeting (IEDM), which this year was organized online (December 12-18, 2020), is a key forum for reporting developments in semiconductor and electronic device technology. 

Nature Electronics Research Highlights

Gate-all-around transistors stack up by Stuart Thomas; Nature Electronics	Gallium nitride gets wrapped up by Stuart Thomas; Nature Electronics
Vacuum transistors with high-power operation Matthew Parker; Nature Electronics	Beam scanning on a single chip Matthew Parker; Nature Electronics
FinFETs for cryptography Christiana Varnava; Nature Electronics	Electronics in an organic package Christiana Varnava; Nature Electronics

[mos-ak] [online publications] Virtual International MOS-AK Workshop, Silicon Valley, Dec. 10-11, 2020

Local organization THM Team together with the International MOS-AK Board of R&D Advisers as well as all the Extended MOS-AK TPC Committee have organized two days virtual/online event:

• 13th International MOS-AK Workshop,  Silicon Valley, Dec. 10-11, 2020
• virtual session 11:00 - 14:00 (PST) on Dec.10, 2020
• virtual session 11:00 - 14:00 (PST) on Dec.11, 2020

Online Publications:

There are MOS-AK technical presentations covering selected aspects of the compact/SPICE modeling and its Verilog-A standardization (see all the slide presentations online at corresponding link).

Postworkshop Publications:

Selected, best MOS-AK technical presentation will be recommended for further publication in a special Solid State Electronics issue on compact modeling planned for the next 2021 year.

The MOS-AK Association plans to continue its standardization efforts by organizing future compact modeling meetings, workshops and courses around the globe thru the next 2021 year, including:

• 1st MOS-AK Asia/South Pacific, (online) end Feb.2021
  
• 3rd MOS-AK/India Conference, Hyderabad (IN) Rescheduled 2021
• MOS-AK at LAEDC (MX), April 18-20 2021
• FOSS TCAD/EDA at 5NANO2021, Kottayam (IN) April, 2021
• 5th Sino MOS-AK Xi'an (CN),  Rescheduled 2021
• WCM at the Nanotech, Washington DC (US), Rescheduled 2021
• IRPhE, mmW and THz Conf. Aghveran (AM) Rescheduled 2021
• 19th MOS-AK at ESSDERC/ESSCIRC, Grenoble (F) Sept. 2021
• 14th US MOS-AK Workshop, Silicon Valley (US) Dec. 2021
  in timeframe of IEDM and Q4 CMC Meetings

W.Grabinski on the behalf of International MOS-AK Committee 

WG221220

[paper] Radiation testing of a 6-axis MEMS inertial navigation unit

Radiation testing of a commercial 6-axis MEMS inertial navigation unit at ENEA Frascati proton linear accelerator

G. Bazzano^a,b, A. Ampollini^a, F. Cardelli^a, F. Fortini^a, P. Nenzi^a, G.B. Palmerini^b, L. Picardi^a, 

L. Piersanti^a, C. Ronsivalle^a, V. Surrenti^a, E. Trinca^a, M. Vadrucci^a, M. Sabatini^c

Advances in Space Research (2020)

DOI: 10.1016/j.asr.2020.11.031

^aENEA, Via Enrico Fermi 45, Frascati, Italy

^bScuola di Ingegneria Aerospaziale, La Sapienza Università di Roma, Italy

^cDipartimento di Ingegneria Astronautica, Elettrica ed Energetica, La Sapienza Università di Roma, Italy 

Abstract: We present the first results of a novel collaboration activity between ENEA Frascati Particle Accelerator Laboratory and University La Sapienza Guidance and Navigation Laboratory in the field of Radiation Hardness Assurance (RHA) for space applications. The aim of this research is twofold: (a) demonstrating the possibility to use the TOP-IMPLART proton accelerator for radiation hardness assurance testing, developing ad hoc dosimetric and operational procedures for RHA irradiations; (b) investigating system level radiation testing strategies for Commercial Off The Shelf (COTS) components of interest for SmallSats space missions, with focus on devices and sensors of interest for guidance, navigation and control, through simultaneous exploration of Total Ionizing Dose (TID), Displacement Damage (DD) dose and Single-Event Effects (SEE) with proton beams. A commercial 6-axis integrated Micro Electro-Mechanical Systems (MEMS) inertial navigation system (accelerometer, gyroscope) was selected as first Device Under Test (DUT). The results of experimental tests aimed to define an operational procedure and the characterization of radiation effects on the component are reported, highlighting the consequence of the device performance degradation in terms of the overall navigation system accuracy. Doses up to 50 krad(Si) were probed and cross sections for Single-Event Functional Interrupt (SEFI) evaluated at a proton energy of 30 MeV. 

Fig: Polyedric support for MEMS accelerometer characterization

[paper] Cross Domain Modeling of a Meander Beam MEMS Accelerometer

Cross Domain Modeling of a Meander Beam MEMS Bulk Micromachined Accelerometer

in COMSOL Multiphysics® and SPICE

Mahdieh Shojaei Baghini*

*Department of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, Netherlands

Abstract: This paper presents the design of a bulk Silicon MEMS single-axis 8-beam accelerometer utilizing meander beams in the Structural Mechanics and MEMS Module of COMSOL Multiphysics®. To obtain further insights into the design of the accelerometer, an electrical lumped element model of the structure is derived and represented in SPICE. Quantities such as eigenfrequencies and proofmass displacement have been extracted from COMSOL Multiphysics® as well as analytical studies. The effects of parasitic frequencies in the structure are observed by automatic tilting of the accelerometer at higher order eigenfrequencies due to finite off-axis stiffness coefficients. In order to mathematically quantify the response of the accelerometer arising due to parasitic frequencies, the transient damping response has been derived in COMSOL Multiphysics® as well as SPICE, and the differences are highlighted. Finally, the eigenfrequencies of the meanderbeam accelerometer have been compared with that of a simple-beam accelerometer and the validity of small deflection theory is tested for the lumped model approach. While the target damping factor of the accelerometer was 0.7, the obtained damping factor increased to 1.1 due to the aforementioned parasitic frequencies and reduction in the resonance frequency of the sensor. This effect was precisely captured during the COMSOL Multiphysics® simulation.

Fig: The designated sensor is damped using plates placed at a distance equal to h0; its a) electrical circuit equivalent of squeeze-film damped accelerometer; b) electrical circuit considering symmetric damping; c) simplified equivalent circuit for gap height derivation.