Patent ID: 8609490

Claim:
A method to form a lateral double-diffused metal-oxide-semiconductor transistor, comprising: forming a field oxide on a substrate structure; using a single mask, concurrently forming a gate/source/body opening and a drain opening in the field oxide down to the substrate structure; forming a gate oxide on exposed substrate structure surface in the gate/source/body opening; forming a polysilicon layer over the substrate structure, the polysilicon layer covering the field oxide, the gate/source/body opening, and the drain opening, the polysilicon layer having a minimum thickness in the gate/source/body opening less than a width of the gate/source/body opening; anisotropic ally etching the polysilicon layer down to the field oxide and a portion of the gate oxide, thereby forming polysilicon spacer gates in the gate/source/body opening and a polysilicon extended drain contact in the drain opening, the polysilicon spacer gates being separated by a space over a portion of the gate oxide, the polysilicon spacer gates having base widths that are determined by the minimum thickness of the polysilicon layer in the gate/source/body opening and a duration of the anisotropic etching; forming a body region of a first conductivity in the substrate structure, the body region being self-aligned about outer edges of the polysilicon spacer gates; forming a source region of a second conductivity in the body region, the source region being self-aligned about inner edges of the polysilicon spacer gates; forming an extended drain region of the second conductivity in the substrate structure, the extended drain region being located under the polysilicon extended drain contact and self-aligned with respect to the polysilicon spacer gates, a drift region being formed in the substrate structure between the extended drain region and the body region, and a channel region being formed in the body region between the source region and the drift region.