3D Simulation Method to Predict Breakdown Voltage of Complex Large-Scale Ring Corner in SJ MOSFET

We present a fast and accurate 3D TCAD simulation method to predict breakdown voltage (BV) and charge imbalance process margin in the complicated large-scale ring corner region of a super junction (SJ) MOSFET by building an automatic structure editing algorithm and a proposed BV model. The algorithm automatically analyses 300 ×300 μm
²
GDS within minutes, subdividing it into more than 50 sections based on the pillar design, and creates a 3D structure using physics-based 2D process simulation for each section. The proposed empirical BV model is established by combining the maximum electric-field extracted from 3D TCAD simulation and experimental BV results obtained from different ring corner designs. We developed a 650V-class SJ MOSFET using the proposed method. To find better design solution, the proposed simulation method can be used to analyze the design weakness of the ring corner by evaluating the spatial distribution of the electric field. In addition, the measured BV value and thermal emission microscope images show that the proposed method is accurate in predicting BV levels and BV hot spots. Therefore, it can be seen that the proposed 3D analysis method is valuable for predicting BV in SJ ring corners and can be expanded to other large devices in a fast and accurate way using 3D TCAD.