This title slide introduces suspended graphene field-effect transistors (FETs), focusing on their microfabrication and electrical/mechanical characterization. The subtitle highlights advanced nanotechnology for high-performance transistors.

Microfabrication and Electrical/Mechanical Characterization of Suspended Graphene Field-Effect Transistors

Advanced Nanotechnology for High-Performance Transistors

Source: Academic Presentation Redesign

This agenda slide outlines the structure of the presentation, starting with an Introduction. It covers key sections including Microfabrication Process, Device Characterization, Electrical Results, Mechanical Properties, and ends with a Conclusion.

Presentation Overview

1. Introduction
2. Microfabrication Process
3. Device Characterization
4. Electrical Results
5. Mechanical Properties
6. Conclusion

Source: Microfabrication and electrical/mechanical characterization of suspended graphene field-effect transistors

This section header slide introduces suspended graphene field-effect transistors, focusing on their microfabrication and electrical/mechanical characterization. It covers background on graphene properties, the motivation for suspended structures, and the research objectives.

Microfabrication and electrical/mechanical characterization of suspended graphene field-effect transistors

01

Introduction to Suspended Graphene FETs

Background on graphene properties, motivation for suspended structures, and research objectives

Source: Introduction to Suspended Graphene FETs

The microfabrication process workflow outlines five key steps for creating suspended graphene devices on a Si/SiO₂ substrate: substrate preparation via cleaning and baking, graphene transfer using PMMA-assisted wet transfer and annealing, patterning via RIE with O₂ plasma and photolithography, suspension through HF vapor etching and critical point drying, and electrical contacting with Cr/Au evaporation and lift-off. Each step includes detailed descriptions and specific techniques employed.

Microfabrication Process

Source: Redesign of 'Microfabrication and electrical/mechanical characterization of suspended graphene field-effect transistors'

Electrical characterization employs I-V sweeps to assess conductance and contact resistance, alongside Hall effect measurements in a 4-probe setup at 1.6 K to determine carrier type, density, and mobility versus gate voltage. Key findings reveal mobility exceeding 10,000 cm²/Vs near the Dirac point, ambipolar transport with charge neutrality at Vg ≈ -10 V, electron/hole symmetry, and enhanced transconductance peak visibility.

Electrical Characterization

| • Current-Voltage (I-V) sweeps: Assess conductance and contact resistance.

• Hall effect measurements: Extract carrier type, density (ns), and mobility (μ) vs. gate voltage (Vg). Standard 4-probe configuration at 1.6 K. | • Mobility peaks at >10,000 cm²/Vs near Dirac point.
• Ambipolar transport with charge neutrality at Vg ≈ -10 V.
• Hall data shows electron/hole symmetry (high contrast plots). Improved visibility of transconductance peaks. |

Source: Microfabrication and electrical/mechanical characterization of suspended graphene field-effect transistors

Key Electrical Results show electron mobility exceeding 10,000 cm²/Vs in suspended devices, a ~50 meV Dirac point shift post-annealing, and 10x higher conductance versus supported graphene. Contact resistance variation is under 1% across devices.

Key Electrical Results

• >10,000: Electron Mobility

cm²/Vs in suspended devices

• ~50: Dirac Point Shift

meV post-annealing

• 10x: Conductance Increase

vs. supported graphene

• <1%: Contact Resistance

variation across devices Source: Microfabrication and electrical/mechanical characterization of suspended graphene field-effect transistors

Mechanical characterization involves Raman spectroscopy for strain and doping analysis, alongside bending tests to evaluate flexibility and resilience. Stress-strain curves reveal key mechanical properties, with optimized figure spacing enhancing clarity.

Mechanical Characterization

• Raman spectroscopy for strain and doping analysis
• Bending tests to evaluate flexibility and resilience
• Stress-strain curves revealing mechanical properties
• Optimized figure spacing for enhanced clarity

Source: Microfabrication and electrical/mechanical characterization of suspended graphene field-effect transistors

We fabricated suspended graphene FETs with superior electrical/mechanical properties, low defect density, and high carrier mobility (>10,000 cm²/Vs), demonstrating strain-tunable bandgap and robust structures. Future work includes scaling to arrays, integration with quantum devices, and 2D heterostructures, paving the way for next-gen nanoelectronics—contact us to collaborate.

Conclusions and Outlook

<ul><li><strong>Achievements:</strong> Fabricated suspended graphene FETs with superior electrical/mechanical properties, low defect density, and high carrier mobility (&gt;10,000 cm²/Vs).</li><li><strong>Key Insights:</strong> Demonstrated strain-tunable bandgap and robust suspended structures via advanced microfabrication.</li><li><strong>Future Work:</strong> Scale to arrays, integrate with quantum devices, explore 2D heterostructures.</li></ul><p><strong>Closing:</strong> Graphene FETs pave the way for next-gen nanoelectronics.</p><p><em>Call-to-Action:</em> Contact us to collaborate on cutting-edge 2D materials research.</p>

Thank you | Questions?

Source: Microfabrication and electrical/mechanical characterization of suspended graphene field-effect transistors