On the Modeling and Simulation of Novel Schottky Based Silicon Rectifiers

This report has been written in conclusion to a master's project in the Semiconductor Components group at the University of Twente. The topic is the DC (Direct Current) current voltage characteristic of both the aMSM- (asymmetric Metal Semiconductor Metal) and the CP- (Charge Plasma) diode. We will make a comparison by focusing on the modeling and simulation of both devices, after comparing those to experimental obtained from conventional vertical Schottky diodes. This report reflects the work which has been done during this project and allows the reader to understand the DC current voltage characteristics of the proposed diodes. We present an analytical model for the IV characteristics of both diodes. This model is verified using the Synopsys device simulator. The model and the simulator show a good agreement. It was found that when one of the metal work functions is located much further away from silicon midgap then the other, then it is either the transport of holes or electrons which dominates the current. Both the on- and the off-current can be scaled independently from each other by scaling the n-metal gate and p-metal gate length. An example is shown from which the metal work functions are extracted from experimental Schottky diode test structures. In this case proper scaling of both gate lengths can improve the on/off current ratio of the diode by a factor twenty. In another case work functions from literature were used, here the on/off current ratio couldn't be improved.