Mass characterisation of organic transistors and Monte-Carlo circuit simulation

Abstract

We present a method for designing organic circuits using Monte-Carlo based circuit simulation. The organic devices suffer from mismatch and variations that are due to systematic and random fluctuations in the process and material characteristics. In this work, we have used the variable range hopping model to extract the model parameters using a mass characterisation technique. The parameter fluctuations of organic transistors are taken into account and process corners determined based on static (noise margin) and transient (delay) characteristics. Thus a methodology is developed to find the parameter range of individual devices, within which the circuits are having good performance, for instance inverters working with desired noise margin. We also found out the critical parameters of the transistor, that predominantly affects the static and transient performance of an inverter. These critical parameters can be provided as input to the process engineers to fine tune the process. This information can also be used in developing robust circuit design techniques, which can overcome the variation effects of these critical parameters. Thus, a mass characterisation of transistors combined with the proposed method, allows robust circuit design in the presence of huge process variations.