Fabrication and Evaluation of Organic Field-Effect Transistors (OFETs) : TIPS Pentacene

Fabrication and evaluation of vacuum-deposited TIPS Pentacene [B5942]-based OFETs

< Substrate >

• HMDS-treated Si/SiO₂ (thickness of SiO₂：200 nm) + with PFBT-treated Au electrodes (thickness of Au：40 nm)

< Vacuum Deposition >

• Deposition rate of Au: 0.2 Å/s, (under a pressure of ∼10⁻⁴ Pa)

< Self-Assembly Monolayer (SAM) Treatment >

• PFBT [P0861] (For Au surface treatment) + HMDS [H0089] (For Si/SiO₂ surface treatment)
  1. UV/O₃ treatment (20 min)
  2. Immersion in PFBT [P0861] solution (0.01 M toluene, 3 min, Air)
  3. Exposure to vapor (IPA, 1 min)
  4. Spin-coating of HMDS [H0089] (4000 RPM, 40 sec, Air)
  5. Exposure to vapor (IPA, 1 min)

< Spin-coating >

• TIPS Pentacene [B5942], 1 mg/ml toluene
• Spin-coating condition: 1000 RPM, 60sec, N₂

< Device configuration >

• [n⁺-Si/SiO₂ (200 nm) / Au (40 nm) / TIPS Pentacene [B5942] (15 nm) ]
• Bottom-Contact Bottom-Gate Type (BCBG)
• Channel Length: 50 μm
• Channel width: 1.5 mm

< Evaluation condition >

• Under N₂
• Field-effect mobilities (μ) were determined from the transfer curves in the saturation regime using the following equation:
  I_D = (W/2L) μ Ci (V_G − V_th)²