Evaporation Stack for Long Channel OFETs

Order Code: E191


(excluding Taxes)


The evaporation stack holds the OFET source-drain shadow masks and substrates in close contact for thermal evaporation. This is crucial for effective device fabrication as the source-drain channel is usually the most critical feature on an OFET. For use with the Ossila long channel OFET source-drain evaporation masks (sold separately).



A mechanical support system for use with Ossila's shadow masks to make evaporation of the source and drain contacts for Organic Field-Effect Transistors (OFETs) as simple and quick as possible. The Organic Field-Effect Transistors (OFETs) evaporation stack consists of a mask support which holds the flexible shadow masks in place. A substrate holder that holds up to 12 substrates is aligned with the shadow mask. A weakly-magnetic sheet ensures that the thin bars of the shadow mask which define the channel are held in close contact with the substrate. Finally, a lid bolts everything together for a mechanically stable system for use in a variety of evaporation system in any orientation. Suitable for use in high-vacuum equipment (tested to <10-6 mbar).


OFET evaporaton stack exploded diagram for long channel design       

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.





Designed for use with Ossila standard-sized substrates and with interchangeable shadow masks (substrates and shadow masks sold separately). The top gate shadow mask is also available.


Outer dimensions 75 mm x 75 mm
Number of OFETs 72 (12 standard sized Ossila substrates with 6 OFETs each)
Compatible masks E201, E211 and E261. Custom masks available upon request


OFET geometries available with the Ossila OFET fabrication system

Bottom Gate Bottom Contact OFET on silicon gate with silicon oxide insulatorBottom Gate Bottom Contact OFET on ITO glass with polymeric dielectric
Schematic of bottom gate, bottom contact OFETs using Ossila's source-drain evaporation stack and Si/SiO2 substrates (top) and ITO substrates (bottom).


Bottom Gate Top Contact OFET on silicon gate with silicon oxide insulatorBottom Gate Top Contact OFET on glass ITO with polymeric insulator
Schematic of bottom gate, top contact OFETs using Ossila's source-drain evaporation stack and Si/SiO2 substrates (top) and ITO substrates (bottom).


OFET Source-drain evaporation stack components

OFET shadow mask long channel linearShadow mask long channelOFET substrate supportOFET evaporation stack magnetic sheetEvaporation stack lid photo
Mask Support,  Interchangeable Shadow Masks (sold separately), Substrate Holder, Magnetic Sheet and Lid.


Loading Procedure

How to load OFET evaporaton stack 

Stage 1
The lower support provides mechanical stability to the thin and flexible shadow mask


Stage 2
The shadow masks (interchangeable and sold separately) are then placed upon the lower support.


Stage 3
The substrate alignment plate is placed over the shadow mask.


Stage 4
Substrates are then loaded.


Stage 5
The weakly-magnetic sheet is used to pull the shadow mask into contact with the substrates such that evaporation can be done in any orientation, even upside down.


Stage 5
The lid then bolts everything in place for a mechanically stable system.




Ossila OFET Source-drain evaporation stack demonstration video


Mask Dimensions (mm)

Evaporation stack lower support schematic
Lower Support


Evaporation stack substrate support schematic
Substrate Support


Evaporation stack lid dimensions


To the best of our knowledge, the technical information provided here is accurate. However, Ossila assume no liability for the accuracy of this information. The values provided here are typical at the time of manufacture and may vary over time and from batch to batch.