Ultrafast high power switching diodes

Impressive progress in semiconductor switch technology has been demonstrated at the A.I. Ioffe Physiotechnical Institute in St. Petersburg, Russia. In the moderate voltage (1 kV), moderate current (100 A) regime, the Ioffe group´s technology demonstrates switching times of 2 ns or a di/dt of 5/spl times/10/sup 10/ A/s. In the thyristor area, large diameter devices have demonstrated rates of current rise approaching 10/sup 12/ A/s, which is comparable with spark gaps. A three year research project is underway in collaboration with the Ioffe group which seeks to define the physics, assess the technology, and identify the critical parameters that allow for successful development of semiconductor switches capable of operating at the parameters described above. The initial stage of the program studies individual switches produced by the Ioffe group in order to verify their operational parameters. The second stage of the program will study the physics issues important in achieving the operational specifications. The final stage of the program will suggest modifications to the device manufacture process that may yield further improvements in performance. This paper presents information on a computer-controlled test stand that was developed for testing a variety of components produced by the Ioffe group. Information on circuit modeling using PSPICE and one specific test circuit are discussed. Finally, performance results for two kinds of drift step recovery diodes (DSRD) are presented.