Comparison of design styles for top-gate bottom-contact OTFTs

Process yield, variability and scalability have always been a critical issue for scaling-up circuits in printed electronics. The organic materials and fabrication process as well as physical layout design play a significant role in controlling the performance of Organic Thin Film Transistors (OTFT). In order to design a robust and reliable organic circuit, designers are interested in having stable and predictable OTFTs. In this work, we study the electrical characteristics of OTFTs and digital logic cells for different layout design styles, and provide the statistical analysis of their variability and scalability. Arrays of OTFTs and cells have been designed by using parameterized cells (PCells) and python scripts in order to facilitate design parameters sweep. Very high yield and uniform OTFTs have been fabricated with excellent electrical characteristics. Finally some ring oscillator circuits have been demonstrated as a proof of concept.