Organic field effect transistors (OFET)#
If an (organic) semiconductor layer is deposited on such a substrate, the Si bulk takes over the gate function and controls the current flow between the gold electrodes. A suitably doped Si-SiO2 interface in CMOS quality guarantees a reproducible gate contact. The gold electrodes with patented adhesive layer suppress the formation of injection barriers between the gold electrodes and the organic in the transistor channel, even for p-type semiconductors, so that reliable ohmic source / drain contacts are formed in the OFET.
Due to their reliability and reproducible preparation, these substrates are used worldwide by all major developers of organic semiconductor materials as part of standardised material monitoring.
In the standard OFET layout, a 200 mm wafer has almost 1800 individual transistors on 112 chips, each sized at 15 × 15 mm². Each chip carries four groups with four identical transistors, with a channel length of 2.5, 5, 10, 20 μm respectively). Identical layouts with graded channel widths as well as a flexible selection of the oxide thickness allow the adjustment to a broad voltage and conductivity range of the test materials. Customer-specific layouts with different electrode geometries are possible at any time. In advantage for our customers, beside the wafers we offer wafflepacks with 16 seperated chips.