Simulation study of single-event gate rupture using radiation-hardened stripe cell power MOSFET structures

A two-dimension simulation study of single-event gate rupture (SEGR) in radiation-hardened stripe cell power MOSFETs is reported. Simulations are performed on stripe-cell structures employing three different neck widths. A simple methodology is presented showing how these simulations can be used to approximate the drain and gate biases required to induce SEGR. These biases are then compared with the experimental data and found to be in good agreement. By means of simulations, we investigated the effects of various physical mechanisms and input parameters, which are likely to be important in SEGR and found that impact ionization plays a crucial role in the process. The simulations show that the N+ source and P+ plug are critical to the hardened design (narrower neck widths). Clearly, simulations could become a useful tool in evaluating certain design and processing variations.