An optimized bidirectional lightning surge protection semiconductor device

Abstract

This paper addresses the analysis of a bidirectional lightning surge protection power semiconductor device called the bidirectional breakover diode (BBD). The BBD has a high-speed response, high current capability, and low conduction and switching losses. The influence of the layout on the trigger and holding current values has been studied by means of two-dimensional (2-D) electrical simulations. The length of the peripheral N/sup +/ diffusion together with the location of the edge contact between the metallization and the P/sup +//N/sup +/ diffusions are crucial in optimizing the trigger mechanism and the trigger and holding current values. The turn on of the inner cells has also been analyzed by numerical simulations, showing the effect of the central parasitic P/sup +/NP/sup +/ bipolar transistor at the initial phase of the turn on process. Experimental results have been obtained from fabricated 180-V BBD devices with holding current values in the range of 150-250 mA. The BBD surge protection capability has been corroborated by impulsive tests using a 10/1000 /spl mu/s, 50 A, 1000 V, current pulse. In addition, transient losses have been monitored in order to improve the surge protection capability of the device. Finally, the static and dynamic BBD thermal behaviour has also been analyzed.