Gate-Controlled Reverse Recovery for Characterization of LDMOS Body Diode

Reverse recovery behavior is a useful tool for monitoring lifetime variations in the body diode of power MOSFETs. However, correct interpretation of the laterally diffused MOSFET (LDMOS) reverse recovery is challenging and requires special attention. This is due to the fact that the stored charges in the LDMOS drift region can flow from two different directions with each having different lifetime values. By studying the effects of diode reverse bias and gate voltage on the current flow direction during the reverse recovery, we present a simple approach to extract meaningful lifetime values, which can be used to determine material quality at different locations in the drift region of the LDMOS devices.