OFET Test Board for High Density OFETs

Order Code: E481


(excluding Taxes)


The Ossila High Density OFET Test Board has been designed to enable quick, easy and reliable testing of up to 20 devices. It is compatible with our High Density OFET Fabrication System as well as with our Prefabricated High Density Substrates.

manual iconView our OFET measurement manual



We are pleased to introduce the High Density OFET Test Board which can provide high precision, current-voltage measurement of up to 20 OFETs with each substrate. As such, this test board can speed up your research and help you to achieve more reliable results in greater volumes.

Until now, high density OFETs had to be tested using a mechanical needle probe station which was a delicate and laborious process. The testing slot on this board features 20 gold-plated, spring-loaded pogo connectors to make a reliable electrical contact with each device on the substrate. Not only does this make the testing process far simpler and faster, it also ensures uniform electrical contact with every single substrate tested.

The High Density OFET Test Board has been designed to reduce non-negligible error which often occurs as a result of stray capacitance, electromagnetic noise and difficulty isolating the test components (BNC cables, switches, board). Our test board has the following features to enable precision low-current measurement:

  • Double Ground Plane – to reduce electromagnetic pickup from the environment
  • Intelligent wire tracks – designed to reduce noise, leakage current and stray capacitance
  • “Ideal” switch selection – proven to show almost no extra resistance to current flow when ON, and does not introduce leakages current when OFF

This test board uses BNC connectors to enable incredibly easy connection of the source-drain and gate to an array of test equipment. The substrate to be tested is simply dropped into the testing slot and secured in place with a push-fit lid. The optical window then provides access for photosensitivity, photodoping and sensing measurements.

Exploded view High Density OFET Test Board
Exploded drawing of High Density OFET Test Board with push-fit lid.


OFET measurements are made using two source measure units; one to set the gate voltage and measure any gate leakage current, and the second to sweep either the source (n-type) or drain (p-type) voltage and measure the current. The termination terminal (drain/source for n-type/p-type respectively) is then usually grounded.

Our High Density OFET Board has 8 independent gate switches which makes it suitable for top gate architecture. The board is also neat and compact at just 200 mm2 which is small enough for easy use within a glove box.

The High Density OFET Test Board has been designed with maximum experimental versatility in mind and has the following features:

  • Twin BNC connectors for easy attachment to source measure units (SMUs). Channel B is used for the source or drain connection while channel A measures the gate connection.
  • The Drain and Gate share a common ground in order to eliminate earth-loop currents which is essential for nanoamp range measurements.
  • Gate connection switches to activate the gate connection to Channel A. 8 independent gates.
  • Device sense switches to connect the source (n-type) or drain (p-type) contacts of the 20 individual OFETs to Channel B.
  • Optical window for experimental access. Can be used to either illuminate devices for sensing/doping experiments or microscope inspection or a wide array of optoelectrical measurements.


High Density OFET testboard features
High Density OFET Test Board diagram


High Density OFETs feature 20 individual devices on each substrate which offers a number of benefits over their low-density equivalents:

  • Less man hours are required, both for fabricating and testing the devices
  • A greater volume of statistics can be produced which can provide more robust and reliable research
  • OFET variability is reduced since less individual substrates need fabricating, resulting in more consistent and reliable results
  • Cost per OFET is reduced as a result of higher volume of OFETs per substrate


Compatible Products

The High Density OFET Test Board has been designed to be compatible with our High Density OFET Fabrication System and our Prefabricated High Density Substrates.

Prefabricated substrates can reduce OFET fabrication time by up to 50%; preparing the substrates for use is then simply a case of spinning on your semiconductor. For this reason they are ideal for high throughput material screening experiments where a large volume of reliable statistics are required.

We can provide various substrate designs including linear with fixed channel length, linear with variable channel length and interdigitated. We can also provide the substrates with or without OTS treatment. See all the variations available here or contact us to enquire into custom substrates unique to your research needs.

If you prefer to fabricate your own OFETs, you can use our High Density OFET Fabrication System which contains all the relevant components needed including substrates, interchangeable masks, lower support and lid.


exploded View of High Density OFET fabrication systemHigh Density OFET test chip (finished)
High Density OFET System and our Prefabricated Substrates


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.