Factors determining forward voltage drop and forward blocking in the field terminated diode (FTD)

Using exact numercial solutions of the full set of semiconductor device equations the field terminated diode (FTD) structure is investigated. It is shown that the grid structure reduces current flow by causing the electron current to funnel around the grid and at the same time diverting hole current through the grid. In addition, it is shown that the best tradeoff between forward blocking capability and forward drop for a given grid aspect ratio is achieved by low doped, shallow, and closely spaced grids.