Method, apparatus, and system having super steep retrograde well with engineered dopant profiles

A method for forming a transistor, comprising:

• implanting a substrate to form at least one of an n and p doped region;
• depositing an epitaxial semiconductor layer over the substrate;
• forming trenches through the epitaxial layer and partially through at least one of an n and p doped region;
• forming dielectric isolation regions in the trenches;
• forming a fin in an upper portion of the epitaxial semiconductor layer by partially recessing the dielectric isolation regions;
• forming a gate dielectric adjacent at least two surfaces of the fin;
• and
• diffusing dopant from at least one of the n and p doped regions at least partially into the epitaxial semiconductor layer to form a diffusion doped transition region, wherein the diffusion doped transition region adjacent a bottom portion of the fin has a higher dopant concentration than the diffusion doped transition region adjacent the at least one of the n and p doped region.