Submicron and nanoscale organic field-effect transistors and circuits

The first part of this work is the electrical characterization and numerical analysis of the performance of an organic field-effect transistor (OFET) with novel components such as dielectrics, semiconductors, surface treatment, and electrode material. Since the electrode contact affects the device performance in most cases, a new transistor structure with a number of floating electrodes inserted in a channel was devised to decouple the resistance of the contact and channel. It was shown that the contact was an active component not a passive resistor, as is the case in inorganic transistor. This method can be used to develop accurate analytical models based on experimental data. In addition, a new simulation tool for an OFET has been developed using MATLAB and C language, which provides considerable freedom in order to include charge transport models and application environments that are often necessary for an accurate description of OFETs. Fabricating submicron and nanoscale OFETs and their use in an inverter circuit and rectifier are the second part of the work because decreasing the channel length is expected to enhance device performance by increasing the switching frequency. A nanoscale ambipolar FET consisting of thin layers of p- and n-type semiconductors has been studied which will simplify the fabrication of circuits in ease by removing a masking step for semiconductor. Submicron complementary inverters were studied because complementary circuits possess low power consumption and high noise margins. The characteristics of poly(4-vinyl phenol) (PVP) dielectric were also studied since all organic/polymer submicron circuits are the desired goal. It was found that the PVP and other polymer dielectrics are convenient to use but can be charged depending on the environmental condition and produce unstable output.