Modeling Second Breakdown in PN Junctions with NET-2

A diode model has been constructed which simulates second breakdown and which allows for the calculation of junction temperature as a function of time in the reverse region. The model was generated for the NET-2 circuit analysis code, and also includes avalanche breakdown. Second breakdown is assumed to begin at the critical temperature at which the resistivity is a maximum; at this point the junction area is caused to rapidly decrease, causing an increase in the temperature and the thermally generated leakage current. This results in the rapid voltage drop characteristic of second breakdown. With the addition of temperature calculations in the forward region and capacitive effects, it is anticipated that the model will be useful for predicting second breakdown for general inputs, and in general circuit configurations.