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

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} substratemore » for TMD FETs.« less
Authors:
; ; ; ; ; ; ;  [1]
  1. Microelectronics Research Center, University of Texas, Austin, Texas 78758 (United States)
Publication Date:
OSTI Identifier:
22412609
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 6; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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