HIGH FREQUENCY GRAPHENE TRANSISTORS USING LARGE-AREA CVD GRAPHENE AND ADVANCED DIELECTRICS

2011 ◽  
Vol 20 (03) ◽  
pp. 669-677
Author(s):  
OSAMA M. NAYFEH ◽  
TONY IVANOV ◽  
JAMES WILSON ◽  
ROBERT PROIE ◽  
MADAN DUBEY
Keyword(s):  
High Frequency ◽  
Gate Dielectric ◽  
Chemical Vapor ◽  
Hole Mobility ◽  
Monolayer Graphene ◽  
Large Area ◽  
Cvd Graphene ◽  
Ambipolar Behavior ◽  
Chemical Vapor Deposited ◽  
First Time

Graphene transistors using large area chemical-vapor-deposited (CVD) monolayer graphene and advanced dielectric stacks are constructed and examined. Top-gated devices with a SiO 2/ Al 2 O 3 gate-dielectric have a Dirac Point (DP) located at less than 5 V and asymmetric electron/hole mobility. In contrast, devices based on an advanced AlN interfacial layer have a DP located near 0V and a near symmetric carrier mobility- characteristics that could be more suitable for applications that require ambipolar behavior and low-power operation. For the first time, a measured RF cut-off frequency range of 1GHz is measured for top-gated transistors using CVD graphene. The results are of importance for the realization of graphene based, wafer-scale, high frequency electronics.

HIGH FREQUENCY TOP-GATED GRAPHENE RF AMBIPOLAR FETs USING LARGE-AREA CVD GRAPHENE AND ADVANCED DIELECTRICS

2011 ◽  
Vol 1283 ◽  
Author(s):  
Osama M. Nayfeh ◽  
Madan Dubey
Keyword(s):  
Dirac Point ◽  
Gate Dielectric ◽  
Field Effect Transistors ◽  
Hole Mobility ◽  
Monolayer Graphene ◽  
Large Area ◽  
Electron Hole ◽  
Cvd Graphene ◽  
Graphene Fet ◽  
P Type

ABSTRACTAmbipolar top-gated field effect transistors (FETs) based on large area Cu catalyzed CVD-grown monolayer graphene interfaced to advanced dielectrics have been constructed and examined both for their material and electrical qualities. Interfacing of the graphene with novel insulators/substrates could be tailored for the particular application and provide for enhanced device functionality. In contrast to graphene FETs using SiO2-based top-gate dielectric, which show asymmetric electron/hole mobility (with larger hole mobility), and Dirac point shifted to positive levels, FETs constructed using advanced AlN show Dirac point almost near neutral levels and near symmetric electron/hole mobility. The DP is shifted likely due to compensation of the intrinsic p-type doping by n-type doping introduced by the AlN deposition and potentially via a contribution of polarization-induced carrier density. Finally, we demonstrate a top-gated graphene FET with the first observation of RF operation with GHz cut-off frequency based on large area CVD graphene.

PMMA direct exfoliation for rapid and organic free transfer of centimeter-scale CVD graphene

2D Materials ◽  
2021 ◽  
Author(s):  
Hewei Zhao ◽  
Xianqin Xing ◽  
Gehui Zhang ◽  
Wenyu Liu ◽  
Haoyu Dong ◽  
...  
Keyword(s):  
Graphene Film ◽  
Chemical Vapor ◽  
Complete Removal ◽  
Large Area ◽  
Pmma Layer ◽  
Cvd Graphene ◽  
Higher Carrier Mobility ◽  
P Type ◽  
First Time ◽  
Incomplete Domains

Abstract Despite the various techniques developed for the transfer of large area graphene grown by chemical vapor deposition (CVD), the conventional PMMA transferring technique has been widely applied in laboratories due to its convenience and economical cost. However, the complete removal of PMMA on graphene surface has become a troublesome, and the PMMA residue could degrade the properties of graphene significantly. We report here a facile water assisted technique to directly peel off the PMMA layer over centimeter-sized CVD graphene film for the first time. No organic solvents are involved in the whole transfer process. The transferred graphene film is clean and intact over large area because of the cooperative effect of the capillary force and the van der Waals force which facilitates the conformal contact between graphene film and the substrate. Various types of graphene samples (i.e. monolayer, multilayer, and incomplete domains) can be easily transferred to diverse substrates including silicon wafer, sapphire, and quartz with good integrity. The transferred graphene film is of high cleanliness, and the graphene transistors show higher carrier mobility and lower level of p-type doping comparing to the conventional wet transfer technique.

Plasma-assisted chemical vapor deposited silicon oxynitride as an alternative material for gate dielectric in MOS devices

2006 ◽  
Vol 37 (1) ◽  
pp. 64-70 ◽  
Author(s):  
A. Szekeres ◽  
T. Nikolova ◽  
S. Simeonov ◽  
A. Gushterov ◽  
F. Hamelmann ◽  
...  
Keyword(s):  
Gate Dielectric ◽  
Chemical Vapor ◽  
Silicon Oxynitride ◽  
Mos Devices ◽  
Chemical Vapor Deposited ◽  
Alternative Material

Characteristics of Large-Area Plasma Enhanced Chemical Vapor Deposited TEOS Oxide with Various Short-Time Plasma Treatments

2001 ◽  
Vol 685 ◽  
Author(s):  
Ting-Kuo Chang ◽  
Ching-Wei Lin ◽  
Chang-Ho Tseng ◽  
Huang-Chung Cheng ◽  
Yuan-Ching Peng ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Chemical Vapor ◽  
Electrical Strength ◽  
Large Area ◽  
Plasma Treatments ◽  
Chemical Vapor Deposited ◽  
Bias Temperature Stress ◽  
Short Time ◽  
Harmful Effects

AbstractIn this work, high quality silicon dioxide (SiO2) films were prepared by large-area plasmaenhanced chemical vapor deposition (LA-PECVD) using tetraethylorthosilicate(TEOS)-oxygen based chemistry. The effects of various short-time plasma treatments on these as-deposited TEOS oxide were also investigated. Different plasma treatments such as O2, N2O, and NH3 were used in our experiments. Electrical characteristics were exploited to examine the effects of plasma treatments. It was shown that after N2O, and NH3 plasma treatments, the electrical strength of oxide was enhanced. Besides, NH3 plasma treatment exhibited the highest enhancement efficiency. O2- plasma treatment, however, showed some harmful effects on the electrical properties of the TEOS oxide. The reliability tests including charge to breakdown (Qbd) and bias temperature stress (BTS) were also analyzed in these samples. Although better pre-stress characteristics were observed in those samples treated by NH3-plasma, samples with N2O plasma treatment showed superior stress endurance. Consequently, N2O plasma treatment seems to be the best candidate for future TFTs under the consideration of long-term reliability.

scholarly journals Electrical Homogeneity of Large-Area Chemical Vapor Deposited Multilayer Hexagonal Boron Nitride Sheets

2017 ◽  
Vol 9 (46) ◽  
pp. 39895-39900 ◽  
Author(s):  
Fei Hui ◽  
Wenjing Fang ◽  
Wei Sun Leong ◽  
Tewa Kpulun ◽  
Haozhe Wang ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Chemical Vapor ◽  
Large Area ◽  
Chemical Vapor Deposited
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