Название: Amorphous Silicon Thin-Film Transistors: Operation, Modelling and Applications
Автор: Zoubeida Hafdi
Издательство: Springer
Год: 2023
Страниц: 141
Язык: английский
Формат: pdf (true), epub
Размер: 10.1 MB

This book explains the basic elements that readers need to know about amorphous silicon material and a-Si:H TFTs. It includes the main principles of the transistors operation, modeling and applications. Fundamentals about transport mechanisms in a-Si:H TFTs and the associated electronic properties are introduced and extended to design examples and strategies to build reliable, large-area, performance optimized circuits. The book also reviews the effect of the amorphous silicon nature and how it impacts the transistors properties and their relevant applications. Fundamentals are made as simple as possible to be easily grasped as they cover everything expected to be important for an easy understanding of the introduced concepts.

The idea that one-day amorphous silicon (a-Si) will be used for large-scale manufacturing of complex integrated circuits (ICs) was too ambitious to be realized because of its immaturity due to the degraded performance of the material. Remarkable progress has been made since 1975, when Spear, Lecomber and Madan of the University of Dundee in Scotland [1] showed that the amorphous silicon conductivity could be controlled. It turned out at that time that the issue was familiar to only a few physicists in the scientific community who had not yet realized the importance of this emerging technology.

Comparing to crystalline silicon-based electronic devices, electronic properties of those based on amorphous silicon are not suitable for applications requiring high functioning speeds. a-Si:H TFTs are thus acquiring more importance in applications where strict frequency specificities are not critical. They are now established as forming a part of a low-cost technology for a significant domain of applications in the microelectronics domain especially photovoltaics, large area electronics, sensors and currently flexible electronics. In flat panel displays, these transistors are particularly suitable in the design of switching elements in the matrices forming these panels because of their low off-state current. The applications extend from digital imaging applications, to active matrix liquid crystal displays and active matrix organic light emitting diodes (AMOLEDs), a-Si:H gate drivers for LCD applications and X-ray detection. Owing to thin-film technology improvement over the past years, thin-film transistors have known a great development in terms of electronic applications.

The book is dedicated to undergraduate and graduate students. It is also appropriate for device and circuit simulator developers, integrated circuits designers and manufacturers, as well as everyone who would like to have introductory concepts in thin-film transistors based on amorphous silicon. Fundamentals are made as simple as possible to be easily grasped as it includes the main principles of the a-Si:H TFT operation and modeling.

The remainder of the book sheds light on some important applications for a-Si transistors that expose the challenges with amorphous silicon circuit design. Possible improvements in a-Si technology depend not only on the understanding of the device physics but also on its implementation in circuits and systems. Therefore, superior stability and feasibility come into question. Once the operation and characteristics of these circuits are thoroughly understood, the results can then be extended to the design of more complex circuits. Such study is provided in this book for some basic logic gates, namely an a-Si inverter, nor and nand gates. a-Si-based digital circuits still operate at low frequencies, high supply voltages, have diode-connected load transistors and the dynamic power is small in comparison to the static power. For any integrated circuit technology used in digital design, digital circuits can be modeled as an inverter. A more comprehensive look at these basic circuits is taken investigating their performance and exploring the trade-offs available in their design. The investigation of such gates may serve as a foundation for the design and implementation of a-Si logic circuits.

Contents:
1. Introduction
2. Hydrogenated Amorphous Silicon Thin-Film Transistors
3. Amorphous Silicon-Based MIS Structure
4. Hydrogenated Amorphous Silicon Thin-Film Transistor: A DC Analysis
5. Interface States in Amorphous Silicon Thin-Film Transistors
6. Hydrogenated Amorphous Silicon Thin-Film Transistor: A Dynamic Analysis
7. Amorphous Silicon Thin-Film Transistors for Digital Circuits
8. Amorphous Silicon Thin-Film Transistors for Charge Pump Circuits