Very low forward drop JBS rectifiers fabricated using submicron technology

Abstract

Summary form only given. The impact of using submicron technology (0.5- mu m design rules) on JBS (junction barrier controlled Schottky) rectifiers is examined. Two-dimensional numerical simulations demonstrate that decreasing P/sup +/-junction width and depth improves the on-state voltage drop. This is due to the improved utilization of the active area for the Schottky region and improved spreading of majority carrier current from the Schottky contact. However, a junction depth of less than 0.3 mu m results in an undesirable high electric field at the Schottky interface during reverse bias, leading to barrier height lowering, which produces a large leakage current. A large reduction in the spreading resistance is possible by increasing the N-epitaxial layer doping and by reducing the cell pitch in order to achieve the same pinch-off voltage. However, increasing the doping above 2*10/sup 16/ cm/sup -3/ reduces the breakdown voltage below 25 V (which is required for 5 V power supplies). The simulations showed that, by using a proper choice of N-doping and P/sup +/-linewidth, one can reduce the leakage by one to two orders of magnitude as compared to a conventional Schottky buried diode. Experiments conducted to verify the simulations clearly demonstrate that the use of submicron technology can lead to significant improvement in JBS rectifier characteristics. >