Platinum OFET Test Chips (High-Density)

Order Code: S403
Price excludes taxes
Not in stock (price excludes taxes)

Due to high demand, the 5 micron constant interdigitated channel length test chips (S411) are currently out of stock. Please contact us for more details on the expected return date.

Ossila's new range of robust and reusable platinum test chips are designed to save you time and money.

The OFETs were patterned via photolithography, meaning very narrow channel lengths are acheivable.

The platinum is sputtered onto a titanium adhesion layer to provide an extremely robust contact and channel allowing it to withstand cleaning procedures such as solvent sonication, plasma etching, and swabbing. This allows the test chips to be reused multiple times for testing various materials saving a significant amount of time and money. 

NOTE: Patterning using photolithography leaves exposed edges of the titanium adhesion layer. The consequence of this is that charge injection into the semiconducting layer can occur from the adhesion layer boundary instead of the platinum. Therefore these devices are recommend for single-crystal or single-flake materials that can sit on top of the electrode and span the electrode gap.

Mobility screening is made quick and simple with our prefabricated high density test chips, by depositing your semiconductor directly onto the surface you can create up to 20 OFETs on a single chip. In addition when using our  high-density OFET test board you can test an entire chip in as little as 3 minutes reducing the overall time of both fabrication and measurement.


Quantity Price
S403 Linear 1 mm 2-10 μm Variable 1 £83
S411 Interdigitated 26.6 mm 5 μm 1 £83


User Manual User Manual


Substrate / Gate Silicon (p-doped)
Gate dielectric 300 nm thermally grown silicon dioxide
Source-Drain electrodes Platinum (100 nm) / Titanium adhesion layer (5 nm)
Depostion method Plasma sputtering
Patterning method Photolithography



Ossila High Density Substrates feature 20 OFETs which can benefit your research in a number of ways. Firstly, production cost is reduced as a result of a higher volume of OFETs per substrate compared to the low density equivalents. This can help to stretch your budget to allow you to produce and test larger numbers of OFETs.

Secondly, producing OFETs is a far faster and less laborious process. Fabrication time is reduced by up to 50% when using prefabricated high density OFETs, freeing up more time to test the devices. As a result of this, greater volumes of statistics can be produced which in turn can provide more robust and reliable research.

Furthermore, OFET variability is reduced since a larger number of OFETs are produced with each fabrication. At Ossila we have optimised the fabrication process in order to produce consistently high quality substrates. In this respect, using our prefabricated substrates rather than fabricating your own can help you to gather more reliable data to benefit your research project.

Prefabricated high density substrates are ideal for mobility testing as they enable swift, efficient testing of high volumes of OFETs. The Ossila high-density OFET test board has been designed for this purpose. 

Rather than using a mechanical probe station to test OFETs, which is a delicate and time-consuming process, the high density test board allows testing of multiple OFETs at one time; simply drop the substrate into the test slot, secure the push-fit lid and connect the board via its BNC connectors to an array of test equipment.

The board has been intelligently designed to reduce external noise, leakage current and stray capacitance in order to provide reliable and precise low-current testing.


High density FET mobility test board
The Ossila High Density OFET Test Board, designed for rapid, reliable testing of multiple OFETs.



We fabricate p-doped silicon substrates with an insulating 300 nm silicon oxide top layer. Platinum is deposited on top to produce gate electrodes which also cover the conductive edge of the substrate. It is therefore essential that the edge of the substrate is conductive and not covered with the silicon oxide layer. If not, the silicon oxide must be scratched off the sides of the substrates before it can be used.

Prefabricated OFET: gate electrode details
Structure of our prefabricated silicon/silicon oxide substrates.


At Ossila we have optimised the fabricating process to ensure that the edges are conductive and the substrate immediately ready to use.

We fabricate our high-density substrates with 5 nm of titanium and 100 nm of platinum.

For individual details and dimension drawings of each substrate type see below.


Linear 1 mm x 2 µm variable channel length substrate (S403)

Geometry Linear
Arrangement 20 OFETs, 5 channel widths
Channel width 1 mm
Channel length 2, 4, 6, 8, and 10 µm
Variable platinum OFET schematic
Dimension drawing of 1 mm x 2 µm substrate.


Interdigitated 22.6 mm x 5 µm constant channel length substrate (S411)

Geometry Interdigitated
Arrangement 20 identical OFETs
Channel width 22.6 mm
Channel length 5 µm
interdigitated 50 micron channel HD FET schematic
Dimension drawing of one of the 22.6 mm x 5 µm devices on the high density substrate.


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.