Inherently soft free-wheeling diode for high temperature operation

Abstract

Traditionally, the major driver in IGBT and diode development is to minimize the static and dynamic losses. A significant reduction of the n-base thickness would yield this, however it can also jeopardize the switching characteristic leading to high overshoot voltages during diode reverse recovery. In this paper, we present an improved Field-Charge Extraction (FCE) concept that is achieving a soft reverse recovery behavior inherently. The new design allows for a 10% reduction of the thickness of the diode's n-base, while still maintaining the blocking capability and the softness of the conventional diode. Therefore, the technology curve and the ruggedness are improved significantly.