3D simulation study of 375V partial SOI SJ LDNMOS BDS limitation

Full physical 3D TCAD are often limited to smaller geometries. As the simulation domain increases in size an emulation approach is often taken with lower accuracy [1]. The 375V partial SOI LDNMOS is a large device with a complex, high aspect ratio, multi-region deep trench isolation (DTI) termination structure combined with the HW diode. Additionally, the device has a multitude of small floating silicon regions and a significant amount of silicon/oxide interfaces, coupled with floating field plates. As such, a complete 3D simulation was impossible. A new methodology of domain decomposition using Silvaco’s Victory 3D TCAD [3] has been introduced. The device is broken down into several elements, small enough to enable usage of Monte Carlo Implantation and physical annealing models. After the process simulation, the elements are then joined and re-meshed for device simulation.