SILICIDED TRENCH CONTACT TO BURIED CONDUCTIVE LAYER

摘要

A trench contact silicide is formed on an inner wall of a contact trench that reaches to a buried conductive layer in a semiconductor substrate to reduce parasitic resistance of a reachthrough structure. The trench contact silicide is formed at the bottom, on the sidewalls of the trench, and on a portion of the top surface of the semiconductor substrate. The trench is subsequently filled with a middle-of-line (MOL) dielectric. A contact via may be formed on the trench contact silicide. The trench contact silicide may be formed through a single silicidation reaction with a metal layer or through multiple silicidation reactions with multiple metal layers.

主权项

1. A semiconductor structure comprising:
a buried conductive layer in a semiconductor substrate; a trench contact silicide contacting said buried conductive layer and contacting a top surface of a semiconductor layer located above said buried conductive layer; a middle-of-line (MOL) dielectric located on and within said trench contact silicide; and a doped semiconductor region that is topologically homeomorphic to a torus, wherein an inner sidewall of said doped semiconductor region laterally contacts a sidewall of said trench contact silicide, and an outer sidewall of said doped semiconductor region is adjoined to, and underlies, said trench contact silicide.