Efficacy of Charge Sharing in Reshaping the Surface Electric Field in High-Voltage Lateral RESURF Devices

A simple one-dimensional (1-D) analytical solution method for analyzing and determining the breakdown properties of reduced surface field (RESURF) lateral devices is presented. The solution demonstrates quantitatively and qualitatively the reshaping and reduction of the electric field and its dependence on the device/process key parameters. The solution is based on a simple and physical charge-sharing approach that takes into account the modulation of the lateral depletion layer spreading caused by the vertical depletion extension, and therefore transforms the inherent two-dimensional effects into a simple 1-D equivalent. It also provides a reasonable insight on the breakdown voltage sensitivity of lateral RESURF devices to key device/process parameters that other researchers failed to provide. Using the technique, device designers can set and choose the optimal processing window of the device's critical layers to yield high breakdown voltages. The results obtained using the proposed solution method agree well with the experimental and simulation results.