Moat-etched Schottky barrier diode displaying near ideal I–V characteristics

Abstract

A simple fabrication technique for Schottky diodes allows achievement of high breakdown voltage without sacrifice of speed at any current level. We have found the reverse blocking voltage of a Schottky diode can be increased to 80–90% of the bulk breakdown voltage of the silicon wafer by moat-etching into the wafer before deposition of the barrier metal. The moat-etched device exhibits the low leakage current and high reverse breakdown voltage characteristic of a guarded Schottky diode, but retains the fast switching speed of a planar device. In addition, it is observed that the moat-etched diode exhibits a lower barrier height than conventional planar or guarded structures so that a smaller junction area is required for given forward current in the moat-etched device. Junction areas as large as 0.11 cm 2 have been investigated.