Process control of threshold voltage in organic FETs

Publication Type:



Electron Devices Meeting, 2004. IEDM Technical Digest. IEEE International,, p.381-384 (2004)


-17 to 116 V, -27 to 26 V, 2004, 2013 and earlier, C-V characterization, circuit design, circuit functionality, Circuit synthesis, circuit yield, Conductivity, Dielectrics, electron traps, field effect transistors, I-V characterization, integrated circuit design, interface structure, mobile charges, OFETs, optical measurements, organic FET, organic polymer gate dielectric, organic semiconductors, oxygen plasma treatments, parasitic bulk conductivity, Pentacene, Plasma measurements, Polymers, process control, semiconductor-dielectric interface traps, Threshold voltage, threshold voltage control, trap-introduced charges, UV-ozone treatments, voltage control


We report a technique for systematically modifying the threshold voltage of pentacene organic FETs at the process level. Threshold voltage control
is critical to practical circuit design using OFETs, since it ultimately
determines circuit functionality and yield. This work shows that oxygen
plasma and UV-ozone treatments of an organic polymer gate dielectric,
parylene, introduce traps at the semiconductor-dielectric interface. We
model the effects of trap-introduced charges as both fixed charges that
shift the threshold voltage and mobile charges that increase parasitic
bulk conductivity. I-V and C-V characterization confirm that threshold
voltage can be varied from - 27V to +26V by exposure to UV-ozone and from