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Long Channel OFET Fabrication System Overview

The Long Channel Organic Field-Effect Transistor (OFET) source/drain evaporation stack is designed to make fabrication as simple as possible so you can focus on material testing rather than fabrication.

Note that this is our original OFET design and is provided for legacy support and specialist purposes but in general has been superseded by our Low Density and High Density OFET fabrication systems.

We provide OFET shadow masks, substrates and mechanical support that fit together to produce a simple-to-use fabrication system for top/bottom contact OFETs. Using our source/drain evaporation stack, makes it easy to evaporate the source/drain contacts onto our standard size substrates (20 mm x 15 mm).

Below is an exploded-view diagram of the source/drain evaporation stack. The key component is, the shadow mask. However, to make high-quality OFETs it is crucial for the mask to be in close contact with the substrates - which can be difficult in many evaporators which hold substrates upside down. As such, we've designed our system to provide this close contact no matter what angle it is held at. Two mechanical supports hold the OFET mask flat and the substrates in place. A magnetic sheet then pulls the thin bars which define the channel between the source and drain into close contact with the substrate. A lid bolts everything in place for a mechanically stable system suitable for use in a variety of evaporation systems.

The stack will accommodate up to 12 substrates, each of which has six OFETs with standard source/drain contacts of 2 mm x 4 mm. Interchangeable masks allow for different mask designs.

OFET Source/Drain Evaporation Stack

Long channel OFET evaporation stack 3D schematic


Holds the substrates and magnetic sheet in position

Magnetic sheet

Pulls the shadow mask into contact with the substrate - even upside down


Up to twelve substrates per mask (sold separately)

Upper support

Holds and aligns the substrates in position above the shadow mask

Shadow mask

Interchangeable shadow masks with varying designs. Six OFETs per substrate

Lower support

Provides mechanical support to the thin and flexible shadow masks

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