Isolation structure and device structure including the same

Abstract

An isolation structure is described, including a doped semiconductor layer disposed in a trench in a semiconductor substrate and having the same conductivity type as the substrate, gate dielectric between the doped semiconductor layer and the substrate, and a diffusion region in the substrate formed by dopant diffusion through the gate dielectric from the doped semiconductor layer. A device structure is also described, including the isolation structure and a vertical transistor in the substrate beside the isolation structure. The vertical transistor includes a first S/D region beside the diffusion region and a second S/D region over the first S/D region both having a conductivity type different from that of the doped semiconductor layer.

Dependencies are inferred from the claim text.