Overview Description of Power Semiconductor Devices for Power Applications Based on a Literature Study

Rapport, 2007

The use of semiconductor components has come to play an important role in the development of modern power electronic applications. The main criteria for a semiconductor adapted for these types of applications are their ability to handle large currents and voltages. Semiconductor components with a current rating of more than 1 Ampere are generally referred to as power semiconductors. The basic physical mechanisms of these devices are in general the same as for low power devices, but when dealing with high voltages, the concept of plasma is often used in order to reduce the losses of the component. Plasma in a power semiconductor is a mixture of positively and negatively charged particles that plays an important role in defining the characteristics of a power semiconductor and will consequently be dealt with thoroughly. Even though power electronics is a constantly growing industry, the available literature covering this topic can be considered to be somewhat limited. The continuous development of power semiconductors that has taken place under the last decades makes this compilation essential for further work with power semiconductors. This report is a literature study that covers the underlying physics of a semiconductor, gives an overview and insight of how they work, and gives a brief explanation of their operating characteristics. The power semiconductor devices addressed in this report are mainly used in low to medium power applications, i.e. MOSFETs and IGBTs. In addition to this, there are semiconductors that handle even higher currents and voltages, up to several tens of kilovolts. However, even though the basic operating principles do not differ that much, these devices are out of scope for this report. The main intention of this report is to serve as a basis for further studies in the project ‘Reduction of EMI from Switched Power Converters’ financed by Ericsson AB/SAAB Microwave Systems AB, Volvo Car Corporation, SKF AB and Vinnova.