Fabrication and characterization of polymer based metal-oxide-semiconductor and non-volatile memory devices

Organic field-effect transistors (FETs) have been widely investigated due to their potential applications in low cost, large area, and flexible electronics. Despite the rapid progress in organic FETs there are still obstacles- high density of defect in organic semiconductor and poor interface between dielectric and organic semiconductor, which leads to relatively high operating voltage.;Due to the large bandgap, polyfluorenes are very promising organic semiconductor for blue emitting display application. The electrical characteristics of ethyl-hexyl substituted polyfluorene (PF2/6) devices rely on the type and quality of polymer semiconductor and dielectric. Trapped and interfacial charges have significant impact on the performance of polymer light-emitting diodes and FETs resulting in delay time of electroluminescence at low voltages and voltage instability. Electrical measurement allows the extraction of material parameters, such as doping density, mobility, and interface states density.;In this dissertation, detailed charge transport characteristics of PF2/6 using hybrid metal-oxide-semiconductor (MOS) structures are presented. Capacitance-voltage and conductance-voltage measurements give insight into the presence of distribution of trap charges at the dielectric/polymer semiconductor interface and bulk of polymer. By thermal annealing of PF2/6 film to a semicrystalline phase, the device characteristics such as field-effect mobility as well as the interface properties of dielectric/(PF2/6) are significantly improved.;Charge storage characteristics of MOS structure containing size tunable sub-2 nm Pt nanoparticles between Al2O3 tunneling and capping oxide layers were studied. Significantly different amounts of memory window were obtained with the different size of Pt nanoparticles embedded in the MOS structure and reached a maximum of 4.3 V using 1.14 nm Pt nanoparticles, which corresponds to the largest particle density and optimum interparticle distance obtained in our particle deposition method. Satisfactory long term non-volatility was attained in a low electric field due to the Coulomb blockade and quantum confinement effects in ∼1 nm Pt nanoparticle. These properties are very promising in view of device application. Further, our metal nanoparticle formation at room temperature is integrated to polymer dielectric and semiconductor to produce polymer-based non-volatile memory.