FIPMS267

Back-gated LOFET Circuit Substrate

transistors, inverters and ring oscillators, Ti/TiN source/drain, Au contact, 200 nm gate-insulator, chips (diced)

• UNSPSC Code: 43211915

Properties

• form: chips (diced)
• packaging: pack of 1 (wafer of 56 diced chips)
• storage temp.: 15-25°C

Description

General description

Substrate: 150 mm wafer according to semiconductor standard
Structure classes: transistors, inverters, and ring oscillators, additional technology test structures, basic circuits
Die size: 15 × 15 mm²
No. of dies: 56
No. of pads: 39 + 2
Pad size: 1200 × 800 μm²
Gate oxide: 200 nm ± 10 nm
Structured layers: 3 (gate, contacts, source/drain)
Gate layer: Ti/TiN, Rs about 10Ω/sq
Contacts: standard 20 × 20 μm², R around 20Ω
Top layer: 70 nm Au with 10 nm high work function adhesion layer (ITO), by lift-off technique, Rs about 0.65 Ω/sq/ 0.45 Ω/sq
Documentation: included in shipment
Shadow mask: possible, but not required
Probecard: possible, but not required
Protection: resist protection layer (AR PC 5000/3.1, soluable in AZ-thinner or acetone)

Transistors (11)
Connections:

• shared gate (2 pads on different chip sides)
• shared source (2 pads on different chip sides)
• drain for each transistor

Measurements

• transfer and output characteristics for each transistor to evaluate new organic semiconductors or to monitor organic material fabrication

Characterization

• designed for parameter extraction to obtain simulation models

Description see manual

Inverters (4)
All 4 inverters are used within the ring oscillator stages or output drivers
Connections

• shared gate IN for the active transistors (2 pads on different chip sides)
• shared gate GEX for the load transistors (2 pads on different chip sides)
• shared VSS
• VDD and output OUT pads for each inverter

Layout

• Layout designed for single transistor separation
• Channel length of all transistors: L=5 μm

Measurements

• Inverter (input/output) characteristics for rapid monitoring of organic materials
• Supply voltages on VDD and VSS (e.g. for p-type organic material: most positive voltage connected to VDD and ground connected to VSS)
• Voltage on IN (gate of active transistor) with value between VDD and VSS
• Different voltage on GEX (gate of load transistor) changes driver/load ratios
• Important: measure output voltages with high impedance volt meter

Ring oscillators (4)

• Connections - left edge (2 ring oscillators)
• shared gates (GATE_1_2) for all load transistors
• shared VSS
• VDD and output OUT pads for each oscillator

Connections - right edge (2 ring oscillators)

• shared gates (GATE_3_4) for all load transistors
• shared VSS
• VDD and output OUT pads for each oscillator

Layout

• 7 or 15 ring stages
• Simple inverter layout or inverter layout, designed for single transistor separation
• Different driver/load ratios
• Channel length of all transistors: L=5 μm

Measurements

• Measure result: oscillation frequency on OUT and calculated inverter delay
• No input signal required
• Supply voltages on VDD and VSS (e.g. for p-type organic material: most positive voltage connected to VDD and ground connected to VSS)
• Different voltage on GEX (gate of load transistors) changes driver/load ratios
• Changing these voltage (more positive or more negative than VSS) triggers oscillation
• Measure output: high impedance oscilloscope probe required

Application

Back-gated LOFET Circuit Substrate transistors (Lateral organic field-effect transistors) can be potentially used in the fabrication of lighter, flexible, and cost-effective organic electronic devices. They potentially show a lateral hole mobility of 3.3 x 10-5 cm²V^-1s^-1.

Packaging

diced wafer on foil with air tight packaging

Preparation Note

Recommendation for resist removal:
To guarantee a complete cleaning of the wafer / chip surface from resist residuals, please rinse by acetone and then dry the material immediately by nitrogen (compressed air).

Recommendation for material characterization:
If gate currents appear during the characterization of the field effect transistors, considerable variations could occur at the extraction of the carrier mobility. Therefore it is necessary to check the leakage currents over the reverse side (over the chip edges) of the OFET-substrates.

Storage and Stability

Store the wafers at a cool and dark place and protect them against sun.

Resist layer was applied to prevent damage from scratches.
Expiration date is the recommended period for resist removal only. After resist removal, the substrate remains functional and does not expire.

Legal Information

Product of Fraunhofer IPMS