Digital Design Flow Techniques and Circuit Design for Thin-Film Transistors

Thin-Film Transistor (TFT) technology refers to process and manufacture transistors, circuits, Integrated circuits (ICs) using thin-film organic or metal-oxide semiconductors on different substrates, such as flexible plastic foils and rigid glass substrates. TFT technology is attractive and used for applications requiring flexible, ultrathin ICs to enable seamless integration into devices. TFT technology shows great potential to be an enabling technology for Internet of Things (IoT) applications. TFT is currently used and a dominant technology for switching circuits in flatpanel displays and are the main candidates for IoT applications in the near future because of its flexible structure, low cost. It is possible to design different kinds of Application-specific integrated circuits (ASIC) with flexible TFTs. Logic gates are considered as the basic building blocks of a digital circuit. An Integrated circuit (IC) is built from a standard cell library that consists of simple and complex logic gates. In this thesis, using TFTs, a variety of standard cell libraries are built using different logic styles. The designed standard cell libraries are compared with respect to parameters like performance, power and area. A digital ASIC design flow is a crucial and important for any System on Chip (SoC) implementation. The designed libraries are prepared for digital design flow such as synthesis, place and route and sign-off analysis to utilize the benefits of existing automated Electronic design automation (EDA) tools. This research was carried out at Imec. TFT technology transistors were used to design the circuits, standard cells and ICs presented in the thesis.TFT is currently the dominant technology used for switching circuits or switches in an active matrix of flat-panel displays. The key advantages of TFT technologies compared to traditional silicon Complementary Metal-Oxide Semiconductor (CMOS) transistors are that they can be manufactured at low-cost on and low processing temperatures, which allows it to be integrated onto a flexible substrate. Metal-oxide TFT are available only as N-type transistors, since they do not have P-type transistors, the cost of manufacturing goes down. There is an increase in demand to manufacture ICs; the three critical factors which influence the IC industry are power consumption, speed of operation and how small is the IC. Due to this high demand in the competitive market, there is a rise to another parameter known as schedule, which is time to manufacture an IC is very short. The quicker the design is completed helps the companies to seize the market with more opportunities. Designing an IC takes considerable time, the design flow of an IC needs to be accelerated. The increased advancements in the IC industry has increased the complexity of designing an IC. The design flow plays a crucial role in the design process. However, if the design flow is not optimum, the design cycle might take a huge time. Besides, during the design of an IC, it needs to be optimized several times before manufacturing. Therefore long and non-optimum design flow would increase the design lifetime and impacts the schedule parameter. Anybody who wants to design integrated circuits needs a methodology to navigate the complex design process. This methodology is usually called Design Flow. Hence this thesis uses TFT technology to not only to design digital circuits in transistor level but also to characterize and to have an entire digital design flow to design a larger IC