Improving Specific On-Resistance and Breakdown Voltage in SOI LDMOSs with Several N-Type Windows

We propose a lateral double-diffused metal oxide semiconductor (LDMOS) structure in which several N-type windows with higher densities than its drift region are located deep in the drift region. We have named the proposed LDMOS as several N-type windows LDMOS (SNW-LDMOS). This work has two main ideas: the first is to reduce the specific on-resistance due to the presence of the windows with a doping density higher than the drift region. The second is the increase in breakdown voltage due to the creation of new peaks by the N-type windows located in the drift region, where these windows can optimize the distribution of the electric field. On the other hand, these windows modify the electric field by expanding the depletion region in the drift region. Therefore, the breakdown voltage of the proposed SNW-LDMOS transistor increases. Also, the results from a two-dimensional numerical simulation show that, by optimizing the N-windows, the figure of merit and the current flow are significantly improved compared to a conventional LDMOS device.