Silicon Sensors and Actuators

As steadily increasing use is being made of microelectronics in many measuring and control systems in laboratories, plants, offices, hospitals and homes, the technical community is starting to realize that the further penetration of microelectronics into new products and markets is seriously being hampered by the lack of input transducers or sensors, which have a performance/price ratio comparable to that of microelectronic circuits. To narrow this gap, an ever-increasing amount of research and development is being devoted to the field of sensors. One of the results of this increased activity is a new class of sensors, called Silicon Sensors or Integrated Sensors. The aim of this book is to present an introduction to the most important research work being carried out in this area and to the physical effects on which the sensors are based. There are several different ways in which sensors can be grouped. It is possible to group them according to the main physical effects employed in the sensors or to group them according to the measurand domains of the desired information. Because sensors often employ more than one physical effect and for ease of reference, the material of this book is divided mainly, though not fanatically, in accordance with the underlying physical principles. In the introduction (Chapter 1) the general principles of measurement and control systems and of signal conversion in sensors are briefly discussed. In Chapter 2 silicon sensors for the measurement of electromagnetic radiation and nuclear particles are presented. Chapter 3 describes silicon sensors for the measurement of mechanical signals such as strain, pressure and acceleration. Chapter 4 describes silicon sensors for the measurement of temperature and temperature differences. Silicon sensors for the measurement of magnetic fields are described in Chapter 5, while in Chapter 6 silicon sensors for the measurement of chemical measurands such as gas concentration, pH and humidity are presented. Chapter 7 gives a short review of silicon-processing technology, special attention is paid to those steps which are of particular interest to silicon-sensor fabrication, such as micromachining. Finally, in Chapter 8 the interface-electronic circuits required to connect sensors to data acquisition systems are presented.