Evaporation Stack for High Density OFETs

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

Datasheet

The key component is the lower support, which is milled from a solid block of aluminium to provide high-precision recesses for individual shadow masks and substrates, and allows mixing-and-matching of shadow masks within a single evaporation.

Size	75 mm x 75 mm
Thickness	2 mm (exc. bolts)
Material	Lower support: milled aluminium Lid: stainless steel Magnetic sheet: vinyl-laminated polymer resin with ferrite powder
Substrate capacity	Radial design: 10 substrates Square design: 12 substrates

Details of high density OFET mask and support — Magnified example of high-density OFET source-drain mask within completed stack.

The diagram below shows an deconstructed view of how the evaporation stack fits together. At the base of the system is the lower support, which prevents the thin and flexible shadow masks from warping. This support has recesses in which individual masks are placed with the substrates placed on top of them. The lid is used to bolt everything together into a mechanically stable system that can be mounted in a deposition system at any orientation. Finally, a thick, low strength magnetic sheet is placed on to pull the shadow mask in close contact with the substrates (note that this differs from the low density evaporation stack where the magnetic sheet is placed underneath the lid).

High-density OFET evaporation stack (exploded view)

Magnetic sheet
Holds the shadow masks flush against the substrates

Lid
Holds the substrates in position

Substrates (sold separately)
Up to ten substrates per mask

Shadow Masks (sold separately)
Mix and match masks with different geometries within the same evaporation

Combined Lower Support (square) and Substrate Holder
Milled from a single piece of aluminium to provide mechanical support for the shadow masks and substrates.

High density substrate holder — Dimensioned drawing of the square orientation lower support for the high-density OFET evaporation stack.

Demonstration Video

PLEASE NOTE: The magnetic sheet should now be placed on top of the lid, so that it can be taken off while the substrates are still secure in the stack, thus avoiding damage to the substrates.

This video demonstrates how to load the high density OFET stack typically used to thermally evaporate (vacuum deposit) source-drain contacts. The video shows the below steps:

Loading the interchangeable source-drain masks into the lower support (this is combined with the substrate holder).

Loading the substrate

Adding the magnetic sheet

Screwing the lid on.

Learn more and get started with high density OFETsThe high density OFET fabrication system makes it simpler and quicker to make and test a large number of devices for statistical and optimisation purposes. Find our more by viewing ourhigh density OFET overview and schematic,contact our OFET teamorbuy the high density OFET stack.

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.