Top-gated chemical vapor deposited MoS{sub 2} field-effect transistors on Si{sub 3}N{sub 4} substrates

Journal Article · Mon Feb 09 00:00:00 EST 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4907885· OSTI ID:22412609

Sanne, A.; Ghosh, R.; Rai, A.; Movva, H. C. P.; Sharma, A.; Rao, R.; Mathew, L.; Banerjee, S. K. ^[1]

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1. Microelectronics Research Center, University of Texas, Austin, Texas 78758 (United States)

We report the electrical characteristics of chemical vapor deposited (CVD) monolayer molybdenum disulfide (MoS{sub 2}) top-gated field-effect transistors (FETs) on silicon nitride (Si{sub 3}N{sub 4}) substrates. We show that Si{sub 3}N{sub 4} substrates offer comparable electrical performance to thermally grown SiO{sub 2} substrates for MoS{sub 2} FETs, offering an attractive passivating substrate for transition-metal dichalcogenides (TMD) with a smooth surface morphology. Single-crystal MoS{sub 2} grains are grown via vapor transport process using solid precursors directly on low pressure CVD Si{sub 3}N{sub 4}, eliminating the need for transfer processes which degrade electrical performance. Monolayer top-gated MoS{sub 2} FETs with Al{sub 2}O{sub 3} gate dielectric on Si{sub 3}N{sub 4} achieve a room temperature mobility of 24 cm{sup 2}/V s with I{sub on}/I{sub off} current ratios exceeding 10{sup 7}. Using HfO{sub 2} as a gate dielectric, monolayer top-gated CVD MoS{sub 2} FETs on Si{sub 3}N{sub 4} achieve current densities of 55 μA/μm and a transconductance of 6.12 μS/μm at V{sub tg} of −5 V and V{sub ds} of 2 V. We observe an increase in mobility at lower temperatures, indicating phonon scattering may dominate over charged impurity scattering in our devices. Our results show that Si{sub 3}N{sub 4} is an attractive alternative to thermally grown SiO{sub 2} substrate for TMD FETs.

• OSTI ID: 22412609
• Journal Information: Applied Physics Letters, Vol. 106, Issue 6; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM OXIDES
CHEMICAL VAPOR DEPOSITION
COMPARATIVE EVALUATIONS
CURRENT DENSITY
DIELECTRIC MATERIALS
ELECTRIC CONDUCTIVITY
FIELD EFFECT TRANSISTORS
HAFNIUM OXIDES
MOLYBDENUM SULFIDES
MONOCRYSTALS
MORPHOLOGY
PHONONS
PRESSURE RANGE PA
SILICON NITRIDES
SILICON OXIDES
SUBSTRATES
SURFACES
TEMPERATURE RANGE 0273-0400 K
VAPORS