METHODS OF FORMING POWER SEMICONDUCTOR DEVICES HAVING MERGED SPLIT-WELL BODY REGIONS THEREIN AND DEVICES FORMED THEREBY

摘要

Methods of forming power semiconductor devices having merged split-well body regions include the steps of forming a semiconductor substrate containing a drift region of first conductivity type (e.g., N-type) therein extending to a first face thereof. First and second split-well body regions of second conductivity type (e.g., P-type) may also be formed at spaced locations in the drift region. First and second source regions of first conductivity type are also formed in the first and second split-well body regions, respectively. A central body/contact region of second conductivity type is also formed in the drift region, at a location intermediate the first and second split-well body regions. The central body/contact region preferably forms non-rectifying junctions with the first and second split-well body regions and a P-N rectifying junction with the drift region at a central junction depth which is less than the maximum well junction depths of the split-well body regions. First and second insulated gate electrodes may also be formed on the first face, opposite respective portions of the first and second split-well regions. Proper choice of drift region resistivity and implant conditions can be used to form a preferred dumbbell-shaped body region and move the location of breakdown within the device to a location which facilitates decoupling of device characteristics. A drift region extension of relatively high conductivity can also be provided along the bottom of the central body region to further limit the degree of coupling between device characteristics.