Novel lateral merged double Schottky (LMDS) rectifier: proposal and design

The authors report a new Schottky structure, called the lateral merged double Schottky (LMDS) rectifier, which utilises the trenches filled with a high barrier metal to pinch off a low barrier Schottky contact during the reverse bias. Two-dimensional numerical simulation is used to evaluate and compare the performance of the LMDS rectifier with the conventional Schottky and the recently reported lateral merged PiN Schottky (LMPS) rectifier. The authors show that the proposed device provides an order of magnitude reduction in the reverse leakage current and three times higher reverse breakdown voltage when compared to the conventional Schottky rectifier. A significant feature of the LMDS rectifier is that, in spite of having only Schottky junctions, it gives an extremely sharp breakdown similar to that of a PiN diode. It is demonstrated that for forward current densities up to 400 A/cm² , the LMDS rectifier can provide twice the current that can be realised using the LMPS rectifier for a given forward voltage drop. Furthermore, it is shown that even up to an operating temperature of 80°C, power losses in the LMDS rectifier are smaller than those found in the LMPS rectifier. The reasons for the improved performance of the LMDS rectifier are analysed, and design tradeoffs between the forward voltage drop and the reverse leakage current are presented