A silicon-carbide mosfet cell structure and method for forming same

In one embodiment, the invention comprises a silicon-carbide MOSFET comprising individual MOSFET cells. Each cell comprises a U-shaped well (228) (P type) and two parallel sources (260) (N type) formed within the well. A plurality of source rungs (262) (doped N) connect sources (260) at multiple locations. Regions between two rungs (262) comprise a body region (252) (P type). These features are formed on an N-type epitaxial layer (220), which is formed on an N-type substrate (216). A contact (290) extends across and contacts a plurality of source rungs (262) and body regions (252). Gate oxide and a gate contact overlie a leg of a well of a first cell and a leg of a well of a second adjacent cell, inverting the conductivity responsive to a gate voltage. A MOSFET comprises a plurality of these cells to attain a desired low channel resistance. The cell regions are formed using self-alignment techniques at several states of the fabrication process.