Floating RESURF (FRESURF) LDMOSFET devices with breakthrough BVdss-Rdson (for example: 47V - 0.28mΩ.cm2 or 93V - 0.82 mΩ.cm2)

In this paper, we propose and demonstrate a novel device concept, which is an extension of the conventional reduced surface field (RESURF) concept. A heavily doped n-type floating region is introduced in the conventional lateral DMOSFET (LDMOS) device structure which allows the breakdown capability of the device to be increased significantly while at the same time making it high-side capable. This floating RESURF (FRESURF) device concept allows the realization of significantly higher breakdown voltage in a thin epitaxy based power IC technology. Several different LDMOS type device structures based on the FRESURF concept are proposed, simulated and experimentally demonstrated. Breakthrough BV_dss-R_dsonA trade-off has been realized using this device, which can be fabricated in a conventional power IC technology without any added process complexity. BV_dss-R_dsonA figures like 47 V 0.28mΩ.cm² or 93 V - 0.82 mΩ.cm² have been realized, which are best reported figures in the industry for this class of power device and on-par with some of the figures achieved using more complicated superjunction technology.