DMOS transistor structure having improved performance

A trench DMOS transistor structure that includes at least three individual trench DMOS transistor cells formed on a substrate of a first conductivity type, said plurality of individual DMOS transistor cells being dividable into peripheral transistor cells and interior transistor cells, each of said individual transistor cells comprising:

• body region on the substrate, said body region having a second conductivity type, wherein said body region has a bimodal distribution across the width of the transistor cells in which they are respectively located;
• at least one trench extending through the body region and the substrate;
• an insulating layer that lines the trench;
• a conductive electrode in the trench overlying the insulating layer;
• and
• wherein at least said interior transistor cells each further include a source region of the first conductivity type in the body region adjacent to the trench, and wherein said at least one trench extends to a depth below the depth of said body region, and
• further wherein the body regions of said peripheral transistor cells are more lightly doped than the body regions of said interior transistor cells.