RESURF Region Variation Induced Current Crowding Effect on HV p-LDMOS

The nonuniform current distribution of high-voltage laterally-diffused metal-oxide semiconductor (HV LDMOS) is an inevitable phenomenon if the process does not consider the shadow effect of implant. It is because some implants to fabricate transistor are not the self-aligned processes and usually tilted at an angle. From T-CAD simulation, it reveals that the width and doping profile of reduced surface (RESURF) regions vary with the location of HV LDMOS, resulting in the current crowding at the shortest RESURF region due to the base push-out induced snapback.